Crustacea: Amphipoda - Universidad de Sevilla

Journal of Natural History, 2002, 36, 675–713

The Caprellidea (Crustacea: Amphipoda) from Ceuta, North Africa, with the description of three species of Caprella, a key to the species of Caprella, and biogeographical discussion J. M. GUERRA-GARCIÂA² and I. TAKEUCHI³ 1 ² Laboratori o de Biologõ Â a Marina, Departamento de Fisiologõ Â a y Biologõ Â a Animal, Facultad de Biologõ Â a, Universidad de Sevilla, Apdo. 1095, 41080 Sevilla, Spain, e-mail: [email protected] s ³ Otsuchi Marine Research Center, Ocean Research Institute, the University of Tokyo, Akahama, Otsuchi, Iwate 028-1102 , Japan (Accepted 16 November 2000) The caprellidean fauna of Ceuta, located on the North African side of the Strait of Gibraltar, was studied with regard to species composition and biogeographical characteristics. A new species, Caprella ceutae n. sp. is described and compared with the closest species of this genus, C. equilibra and C. fretensis. Furthermore, two species, C. tuberculata and C. liparotensis are redescribed in detail. Of the nineteen species collected, three are recorded for the ® rst time in the Mediterranean Sea, i.e. C. fretensis, C. erethizon and C. tuberculata. With regard to biogeographical distribution, the Strait of Gibraltar has a very high proportion of endemic species of the Caprellidea, contributing 30.8% of the Mediterranean endemisms. A key to the 13 species of Caprella from the region of Ceuta is also provided. Keywords: Amphipoda, Caprellidea, Caprella, taxonomy, biogeography, Ceuta.

Introduction Although the caprellidean amphipods are considered to be very important as secondary and tertiary producers in benthic marine communities, they have not been su ciently studied in the Mediterranean Sea. Most general amphipod studies have been focused mainly on gammarids and only little supplementary information is given about caprellids (Nicolaidou and Karakiri, 1989; Conradi et al., 1997; Procaccini and Scipione, 1992; Conradi and LoÂpez-GonzaÂ lez, 1999). Moreover the amphipod fauna of the North African coast has still been relatively unexplored, except for scarce and very fragmented data. Following research on North African 1 Present address: Departament of Life Environment Conservation, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan, e-mail: [email protected] Journal of Natural History ISSN 0022-293 3 print/ISSN 1464-526 2 online Ñ 2002 Taylor & Francis Ltd http://www.tandf.co.uk/journals DOI: 10.1080/00222930010025923

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J. M. Guerra-GarcÌá and I. Takeuchi

amphipods conducted up to the beginning of the twentieth century (Lucas, 1849; Chevreux, 1888, 1910, 1911; Schellenberg, 1928, 1936) and Mayer’s monographs (Mayer, 1890, 1903), a long interval ensued until the recent work of Bakalem and Dauvin (1995), carried out on the Argelian coast, and our previous work on Ceuta (Guerra-Garcõ Â a and Takeuchi, 2000). Material and methods This study was conducted at Ceuta (Northern Africa), during the summers of 1998 and 1999. Caprellids, together with their natural substrata, mainly algae and hydroids, were collected by SCUBA diving at 23 localities along diŒerent depths (A, 5± 15m; B, 20± 25m; C, 30± 35m; D, 40± 45m) (® gure 1). These substrata were collected in plastic bags containing seawater. In addition to SCUBA diving collection, soft bottom samples were taken with box-core and Van veen grabs at 10 localities (® gure 1). The sediment samples were sieved using a 0.5 mm mesh. Caprellids were separated, sorted, preserved in a 10% seawater-formol solution and then identi® ed to species level and counted. Results A total of 1051 specimens was examined and grouped into 19 diŒerent species of caprellids (table 1). The dominant species collected from the hard bottom samples were

Fig. 1. Location of Ceuta in the Strait of Gibraltar. Arabic numerals correspond to localities of Ceuta where caprellids were collected by SCUBA diving (Depth: A, 5± 15 m; B, 20± 25 m; C, 30± 35 m; D, 40± 45 m). Sediment samples are indicated in Roman numerals (grabs were always used between 5 and 10 meters in each locality).

The Caprellidea from Ceuta, North Africa Table 1.

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Species composition of the Caprellidea from Ceuta and number of specimens studied. Hard bottom†

Species Caprella acanthifera Leach, 1814 C. cavediniae Krapp-Shickel and Vader, 1998 C. ceutae n. sp (present study) C. danilevskii Czerniavskii, 1868 C. dilatata KroÈyer, 1843 C. erethizon Mayer, 1901 C. fretensis Stebbing, 1878 C. grandiman a Mayer, 1882 C. hirsuta Mayer, 1890 C. liparotensis Haller, 1879 C. penantis Leach, 1814 C. santosrosai SaÂnchez-Moyano et al., 1995b C. tuberculata Bate and Westwood, 1868 Caprella sp (armata-group) Pariambus typicus KroÈyer, 1844 Pedoculina garciagomezi SaÂnchez-Moyano et al., 1995a Phtisica marina Slabber, 1769 Pseudoprotella inermis Chevreux, 1927 P. phasma (Montagu, 1804)

Soft bottom

Number

%

Number

%

91 5 5 136 1 29 2 3 2 11 72 103 27 50 ± 2

9.7 0.6 0.6 14.5 0.1 3.1 0.2 0.3 0.2 1.2 7.7 11 2.9 5.3 ± 0.2

±

±

172 13 212

18.4 1.4 22.6

±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

± ±

±

± 100 ±

± 86.9 ±

15

13.1 ± ±

±

±

† Mainly composed of the seaweeds Cystoseira usneoides, Asparagopsis armata, Cladostephus verticillatus, Halopteris scoparia and the hydroid Sertularella gayi.

Pseudoprotella phasma Montagu, with 22.6% of total individuals, followed by Phtisica marina Slabber (18.4%), Caprella danilevskii Czerniavski (14.5%), Caprella santosrosai SaÂnchez-Moyano et al. (11%) and Caprella acanthifera Leach (9.7%). The soft bottoms provided only two species of Caprellidea, i.e. Pariambus typicus KroÈyer (86.9%) and Phtisica marina Slabber (13.1%) . Systematics Caprella acanthifera Leach, 1814 Caprella acanthifera Leach, 1814: 404; Mayer, 1882: 39± 43; Mayer, 1903: 77± 78; Stephensen, 1929: 181, ® gure 43; Harrison, 1944: 13± 15, ® gure 5; Krapp-Schickel and Vader, 1998: 952± 957, ® gures 2± 3. Caprella hystrix: KroÈyer, 1843: 585, pl. 8, ® gures 20± 26. Caprella calva: Bate, 1856: 60, ® gure 57. Caprella aspera: Heller, 1866: 55, pl. 4, ® gures 20± 21. Caprella elongata: Haller, 1880: 409, ® gure 45. Caprella acanthifera forma typica: Mayer, 1890: 44; Chevreux and Fage, 1925: 446± 449, ® gures 427± 428. Caprella acanthifera intermedia: Monterosso, 1915, ® gures 1± 2.

Material examined. 1A: two males, two females, two ovigerous females; 2A: one male; 2B: one male, two females, two ovigerous females; 3A: six males, four females, four ovigerous females, four juveniles; 4A: one male; 5A: three males, one ovigerous female; 6A: one male; 7A: two males, two females; 11A: one female; 12B: one female; 13A: four males, two females, one juvenile; 15A: three males, one female; 15B: three

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males, two females, one juvenile; 18A: one male, one ovigerous female; 18C: three female, one ovigerous female; 19A: nine males, 13 females, four juveniles. Caprella cavediniae Krapp-Schickel and Vader, 1998 Caprella cavediniae Krapp-Schickel and Vader, 1998: 961 ± 963, ® gure 7. Caprella acanthifera var. acanthifera: Cavedini, 1982: 494, ® gures 1± 2; Krapp-Schickel, 1993: 774± 779, ® gures 528± 529.

Material examined. 1C: one female; 23A: three males, one female. Caprella ceutae n. sp. (® gures 2± 5) Material examined. 15D: ® ve males. Diagnosis Male. Head with a developed rostrum. Body smooth, except for a pair of dorsolateral projections on pereonite 6. Inferior surface of the third peduncular segment of antenna 1 bearing ® ne setae. Basis of gnathopod 2 one-quarter of pereonite 2 length and carrying small dorsal teeth. Propodus oblong with dorsal setae. Etymology The speci® c name ceutae was chosen to dedicate this species to Ceuta, the locality where specimens were collected. Type material Holotype male from hydroid Sertularella gayi Lamouroux. Depth 40 metres, August 1999, coll. Juan Rodrõ Â guez. Paratypes: four adult males found together with holotype. Holotype and two paratypes are deposited in the Museo Nacional de Ciencias Naturales de Madrid, Spain (No. MNCN 20.06/4647). The other two paratypes are in the Laboratorio de Biologõ Â a Marina, Universidad de Sevilla, Spain. Type locality Ceuta, North Africa, Mediterranean (35ß 54¾ N, 5ß 16¾ 35² W ). Description Holotype male Body length. 8.9 mm Lateral view. Body slender. Head with a well-developed rostrum. Pereonite 2 elongated. Peronites 3, 4 and 5 subequal. Pereonite 6 with a pair of acute dorsolateral projections close to the coxae. Gills. Oval, length ca twice width. Antennae. Antenna 1 about half of body length, with 14 articles in the ¯ agellum; the third peduncular article bearing dense, plumose setae on its inferior surface. Antenna 2 about half length of antenna 1; peduncular articles 3 and 4 carrying nine pairs of long serrated setae; ¯ agellum two-articulate, setose. Mouthparts. Upper lip symmetrically bilobed, pubescent apically. Inner lobe of the lower lip round, outer lobe round apically; both inner and outer lobe pubescent apically. Mandibular process strong; incisor and lacinia mobilis of both left and

The Caprellidea from Ceuta, North Africa

Fig. 2.

Caprella ceutae, new species. Male lateral view. Scale bar: 1 mm.

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Fig. 3. Caprella ceutae, new species. Male. a, lower lip; b, upper lip; c, maxilliped; d, left mandible; e, right mandible; f, maxilla 1; g, maxilla 2. Scale bars: 0.1 mm.

right mandibles ® ve-toothed. Left mandible with a row of three pectinated setae, right with two. Maxilla 1 outer lobe carrying seven serrated spines on its end; article 2 of palp with ® ve robust apical setae and ® ve lateral slender setae. Maxilla 2 inner


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Fig. 4. Caprella ceutae, new species. Male. a, antenna 1; b, antenna 2; c, gnathopod 1; d, gnathopod 2. Scale bars: a, b: 1 mm; c: 0.5 mm; d: 1 mm .

lobe rounded, a little shorter than outer, which is slender; both inner and outer lobe with 15 marginal setae. Maxilliped inner plate rectangular, carrying two teeth, and one simple and seven plumose setae on the apical margin; outer plate, twice as large as inner, with four teeth and ® ve simple setae; palp four-articulate, articles 2 and 3 with long setae on inner margin; article 4 with two rows of setulae on grasping margin. Gnathopods. Gnathopod 1 setose; ischium round, merus and carpus each with marginal row of seven setae posteriorly; propodus posterior margin with two proximal grasping spines. Gnathopod 2 inserted near to the distal end of pereonite 2; basis one-quarter length of pereonite 2, with a strong lateral ridge which bears several small tubercles; ischium round; merus length ca 1.5 times ischium, with an acute projection on its ventral margin; carpus very short; propodus palm slightly convex, proximally with a robust tooth and one spine, distally with a large rectangular process; dorsal surface profusely setose.

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Fig. 5. Caprella ceutae, new species. Male. a, pereopod 5; b, pereopod 6; c, pereopod 7; d, abdomen (ventral view). Scale bars: 0.5 mm.

Pereopods. Pereopods 5, 6 and 7 increasing in length; pereopods 5± 7 basis with a developed carina; carpus and merus with a dorsal row of four setae; palm of propodus concave with two proximal grasping spines. Abdomen. With a pair of large appendages, a pair of lateral lobes and a single dorsal lobe. Abdominal appendage two-articulate; basal article about twice longer than distal one, length ca 1.5 times width; distal segment round, carrying a lateral seta and a distal one or two. Dorsal lobe with two plumose setae. Penes medial, length ca twice width. Remarks The genus Caprella is the largest genus in the suborder Caprellidea. The species closest to Caprella ceutae, n. sp. are C. equilibra Say 1818 and C. fretensis Stebbing, 1878. Specimens of C. equilibra and C. fretensis belonging to the private collection of the senior author (JMGG) collected along the Atlantic and Mediterranean coasts of southern Spain, were examined with the purpose of comparison. The characteristics of C. equilibra from Southern Spain are in complete agreement with those included in the description of Krapp-Schickel (1993). Caprella ceutae is distinguished


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from C. equilibra as follows: (1) in C. ceutae the prominent ventral spine between the second gnathopod, present in C. equilibra, is lacking; (2) C. ceutae lacks a pair of tubercles anteriorly on pereonite 5, however these tubercles are characteristic of C. equilibra; (3) the inferior margin of the third peduncular article of antenna 1 and the dorsal surface of gnathopod 2 have ® ne and dense setae in C. ceutae. These setae are lacking in C. equilibra. Caprella ceutae is also close to the Atlantic C. fretensis, also found in Ceuta (although only two damaged specimens). A detailed comparison betweeen C. ceutae from Ceuta and undamaged specimens of C. fretensis collected by JMGG from Huelva (Atlantic coast of southern Spain) re¯ ected several constant diŒerences between them. In C. fretensis the inferior surface of the second and third peduncular articles of antenna 1 bears rows of short ® ne setae and the propodus of gnathopod 2 is entirely covered with dense setae. These characteristics, present in specimens from Southern Spain, are in agreement with descriptions and ® gures of C. fretensis from the coasts of England and Ireland, included in Chevreux and Fage (1925) and Harrison (1944). Together with these diŒerences in antenna 1 and gnathopod 2 propodus, we have observed that in C. fretensis from Southern Spain the tubercles on the lateral ridge of gnathopod 2 basis and the acute dorsolateral projections on pereonite 6 are lacking. Furthermore, the abdominal appendage s are diŒerent; in C. fretensis the proximal article is ca one-quarter as long as the distal one and half as long as wide. Moreover, the distal article is clearly serrated distally whereas it is smooth in C. ceutae. The present specimens of C. ceutae were collected from hydroids in an area of high transparency; visibility is ca 10± 30 m. depending on the weather. The area, which is located near the top of the Ceuta Peninsula, is exposed to the strong eŒects of local currents. Caprella ceutae lives together with Pseudoprotella inermis Chevreux, 1927, Caprella santosrosa i SaÂnchez-Moyano et al., 1995b, and the Atlantic species C. erethizon Mayer, 1901 and C. tuberculata Bate and Westwood, 1868. Caprella danilevskii Czerniavski, 1868 (® gure 6) Caprella Danilevskii Czerniavski, 1868: 92, pl. 6, ® ® gure 44; pl. 7, ® gures 12± 13. Caprella Danilewskii: Chevreux and Fage, 1925: 454, Caprella danilevskii: McCain, 1968: 22, ® gures 10± Cavedini, 1982: 499; Krapp-Schickel, 1993: 779, ®

gures 21± 34; Mayer, 1890: 58, pl. 5, ® gure 432. 11; McCain and Steinberg, 1970: 16; gure 531.

Material examined. 1A: 53 males, 34 females, four ovigerous females, 36 juveniles; 3A: one male, one female; 4A: one male, one ovigerous female; 6A: two males; 15A: two males, one female. Caprella dilatata Kroyer, 1843 Caprella dilatata Kroyer, 1843: 585, pl. 8, ® gures. 1± 9; McCain, 1968: 38; McCain and Steinberg, 1970: 17; Cavedini, 1982: 499. Caprella acutifrons: Mayer, 1882: 48, pl. 1, ® gure 9; pl. 2, ® gures 12± 22; pl. 4, ® gures 26± 28; pl. 5, ® gures 15, 22± 23. Caprella acutifrons forma typica: Mayer, 1890: 54, pl. 2, ® gure 34; pl. 4, ® gures 62± 63; pl. 7, ® gures 16± 17; Chevreux and Fage, 1925: 452. Caprella acutifrons forma minor: Mayer 1890: 54, pl. 2, ® gure 35; pl. 4, ® gures 54, 64. Caprella penantis forma typica: Schellenberg, 1928: 678; Schellenberg, 1936: 24. Caprella acutifrons forma typica: Fischetti, 1937: 13.

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Fig. 6. Caprella danilevskii Czerniavski, 1868. Lateral view: a, male; b, female. Scale bar: 1 mm.

Material examined. 17A: one male. Caprella erethizon Mayer, 1901 (® gure 7) Caprella erethizon Mayer, 1901: 239± 245, ® gures 1± 3; Mayer, 1903: 101, pl. 4, ® gures 12± 13; pl. 7, ® gure 77; Chevreux and Fage, 1925: 459± 460, ® gure 436; Bertrand, 1941: 9, 17, 20± 23, ® gure 1; Bocquet and Peltier, 1963: 152± 165, ® gures 1± 10, pls. 1± 2.


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Fig. 7. Caprella erethizon Mayer, 1901. Lateral view: a, male; b, female. Scale bar: 1 mm.

Material examined. 2B: three males; 7D: one male; 15D: 12 males, 12 females, one juvenile. Remarks Caprella erethizon Mayer has been considered, as well as C. tuberculata, a rare species (Chevreux and Fage, 1925). The original description of Mayer (1901) was poor, with only the female described. Chevreux and Fage (1925) redescribed the

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female and described the juvenile male of C. erethizon with very schematic ® gures. Bertrand (1941) found an adult male of C. erethizon but he added little information about its morphological characteristics. Bocquet and Peltier (1963) ® nally gave a precise redescription of this species. The specimens of C. erethizon found in Ceuta, North Africa are identical to those described by these authors from RoscoŒ( Atlantic French coasts). This species was previously recorded on Atlantic coasts of England and France and only one specimen has been found on the Atlantic Portuguese coast (Marques and Bellan-Santini, 1985). Caprella fretensis Stebbing, 1878 Caprella fretensis Stebbing, 1878: 31± 4, pls. 5, ® gure 1; Stebbing, 1879: 521; Mayer, 1882: 58; Mayer, 1890: 62± 63, pl. 4, ® gures 38± 39; pl. 5, ® gures 41± 42; Chevreux and Fage, 1925: 457± 459, ® gure 435; Toulmond and Truchot, 1964: 36.

Material examined. 2A: one male; 5A: one male. Caprella grandimana Mayer, 1882 Caprella grandimana Mayer, 1882: 43, pl. 1, ® gure 5; pl. 2, ® gures 23± 29; pl. 4, ® gures 29± 31; Cavedini, 1982: 501, ® gure 2. Caprella acanthifera var. grandimana: Mayer, 1890: 47. Caprella hirsuta f. longimana: Chevreux, 1913: 5, ® gure 1; McCain and Steinberg, 1970: 23. Caprella acanthifera ssp. grandimana : Carausu and Carausu, 1959: 409.

Material examined. 2B: two males, one juvenile. Caprella hirsuta Mayer, 1890 Caprella hirsuta Mayer, 1890: 77, pl. 2, ® gure 19; pl. 4, ® gures 26± 29; Chevreux and Fage, 1925: 449, ® gure 429; McCain and Steinberg, 1970: 23; Cavedini, 1982: 503.

Material examined. 15A: one male; 17A: one male. Caprella liparotensis Haller, 1879 (® gures 8± 11 ) Caprella liparotensis Haller, 1879: 232; Haller, 1880: 404, pl. 23, ® gures 41± 42; Mayer, 1890: 57; Mayer, 1903: 114, pl. 8, ® gure 23; Chevreux and Fage, 1925: 452, ® gure 431; Fiorencis, 1940: 15, ® gure 6; McCain and Steinberg, 1970: 29; Cavedini, 1982: 504. Caprella dentata: Haller, 1880: 744, ® gures 4± 9; Mayer, 1882: 50, pl. 1, ® gure 8; pl. 3, ® gures 1± 9; pl. 4, ® gure 33.

Material examined. 17A: 10 males, one female. Diagnosis Head with developed rostrum. A pair of lateral spines anteriorly on pereonites 2, 3 and 4 in male; in female only on pereonite 3. In male two pairs of dorsal tubercles on pereonite 5, one pair on pereonite 6 and two pairs of small tubercles on pereonite 7. These two pairs on pereonite 7 are lacking in female. Peduncular articles 2± 3 of antenna 1 with dense plumose setae on ventral margin. Basis of gnathopod 2 very short, about one-® fth of pereonite 2, with carina.


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Fig. 8. Caprella liparotensis Haller, 1879. Lateral view: a, male; b, female. Scale bar: 1 mm.

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Fig. 9. Caprella liparotensis Haller, 1879. Male. a, lower lip; b, upper lip; c, maxilliped; d, left mandible; e, right mandible; f, maxilla 1; g, maxilla 2. Scale bars: 0.1 mm.

Material examined Male à’ from the seaweed Cystoseira tamariscifolia Papenfuss. Depth 10 metres, June 1999, coll. JoseÂ Manuel Guerra-Garcõ Â a. Female `b’ found together with male


Fig. 10.

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Caprella liparotensis Haller, 1879. a± d, male. a, antenna 1; b, antenna 2; c, gnathopod 1; d, gnathopod 2. e, female gnathopod 2. Scale bars: 0.5 mm.

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Fig. 11. Caprella liparotensis Haller, 1879. a± d, male. a, pereopod 5; b, pereopod 6; c, pereopod 7; d, abdomen (ventral view). e, female abdomen (ventral view). Scale bars: a± c: 0.5 mm; d, e: 0.1 mm.

à’ . Other specimens studied: nine males collected together with male à’ and female `b’ . Male à’ , female `b’ and three more specimens are deposited in the Museo Nacional de Ciencias Naturales de Madrid, Spain (No. MNCN 20.06/4648 ). The


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other six specimens are in the Laboratorio de Biologõ Â a Marina, Universidad de Sevilla, Spain.

Locality Ceuta, North Africa, Mediterranean (35ß 53¾ 30 ² N, 5ß 17¾ 00 ² W ).

Redescription Male à’ Body length. 8.2 mm Lateral view. Head with a well developed rostrum. A pair of lateral spines anteriorly on pereonites 2± 4. Two pairs of dorsal tubercles on pereonite 5 and 7, One pair on pereonite 6. Gills. Rounded. Length ca 1.3 times width. Antennae. Antenna 1 shorter than cephalon (head1 pereonite 1) and pereonite 2 together; peduncular articles 1 and 2 slightly widened; articles 2 and 3 carrying dense plumose setae on ventral margin and very short ® ne setae on dorsal surface; ¯ agellum 14-articulate. Antenna 2 a little longer than antenna 1 peduncle; peduncular articles 3 and 4 carrying ten pairs of long serrated setae; ¯ agellum two-articulate; basal article with seven pairs of plumose setae. Mouthparts. Upper and lower lip similar to those in Caprella ceutae n. sp. Mandibular molar process strong, bordered by teeth. Pars incisiva and lacinia mobilis with ® ve teeth on each; left mandible with three pectinated setae, right with only two; a row of short and ® ne setae between these pectinated setae and the molar process. Maxilla 1 outer lobe carrying seven serrated spines apically; article 2 of the palp with 11 marginal setae and 13 lateral ones disposed along the surface. Maxilla 2 inner lobe with 12 apical setae, outer lobe with nine setae. Inner plate of maxilliped nearly as large as the outer plate; inner plate with nine plumose setae and three teeth; outer plate with long simple seta and ® ve teeth; articles 2 and 3 of palp carrying many long setae on inner margin; article 4 shorter than article 3, with rows of setulae on its grasping margin. Gnathopods. Gnathopod 1 setose; ischium to merus with many ventral setae; propodus with two proximal grasping spines, palm shallowly convex. Gnathopod 2 inserted near distal end of pereonite 2, as in Caprella ceutae n. sp.; basis short, about one-® fth of pereonite 2, with a very developed carina; ischium round; merus length ca twice ischium, with an acute projection on ventral margin as in Caprella ceutae n. sp.; propodus longer than basis to ischium combined; length ca 2.5 times width; palm concave with one projection bearing a tooth and spine halfway from proximal end, another projection one-quarter length from distal end, followed by Ù’ notch distally. Pereopods. Pereopods 5, 6 and 7 increasing in length; basis with carina on posterior margin; merus and carpus carrying three setae on outer margin; carpus with several pairs of strong setae on the anterior margin; palm of propodus concave with two proximal grasping spines and two anterior rows of short and wide setae. Abdomen. With a pair of two-articulate appendages, a pair of lateral lobes and a single dorsal lobe which carries two plumose setae. Penes short, length about 1.2 times width.

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Female `b’ . Body length 6.8 mm. A pair of lateral spines anteriorly on pereonite 3. Pereonite 7 without dorsal tubercles. Gnathopod 2 inserted on the anterior half of pereonite 2; length of propodus ca 1.5 times width. Brood lamellae of pereonite 3 setose on the posterior margin; brood lamellae on pereonite 4 not setose. Abdomen with a pair of lateral lobes and a dorsal lobe carrying 2 plumose setae. Remarks Although Chevreux and Fage (1925) and Krapp-Schickel (1993) provided detailed descriptions of Caprella liparotensis from Cette ( France) and Napoli (Italy) respectively, we have included complete drawings of antennae, mouthparts and abdomens based on the newly collected specimens from Ceuta. The comparison reveals several diŒerences between the previous descriptions and present specimens from Ceuta: (1) female from Ceuta carries a pair of lateral spines on pereonite 3, while in C. liparotensis from Napoli the female lacks lateral spines on pereonites 2 and 3 ( Krapp-Schickel, 1993); (2) males from Ceuta bear two pairs of tubercles on pereonite 7 while those from Napoli lack these tubercles ( Krapp-Schickel, 1993); (3) the specimens of C. liparotensis from Ceuta possess three teeth on the inner plate of the maxilliped and four to six teeth on the outer plate. Chevreux and Fage (1925) reported that the maxilliped of C. liparotensis was similar to that in C. acutifrons. They described for C. acutifrons (old complex of C. penantis, C. andreae, C. dilatata and other close species) an inner plate with two large teeth and an outer plate with seven to eigth teeth. Nevertheless these diŒerences are not enough to consider these specimens from Ceuta as a new species. Caprella penantis Leach, 1814 (® gure 12) Caprella Penantis Leach, 1814: 404. Caprella acutifrons: Mayer, 1882: 48; Mayer, 1890: 50, pl. 2, ® gures 36± 37, 39± 41; pl. 4, ® gures 52± 53, 55, 57± 61, 65± 69; Mayer, 1903: 79, pl. 3, ® gures 4± 28; pl. 7, ® gures 62± 65. Caprella acutifrons f. testudo: Chevreux and Fage, 1925: 452, ® gure 430. Caprella penantis: McCain, 1968: 33, ® gures 15± 16; McCain and Steinberg, 1970: 33; Cavedini, 1982: 508.

Material examined. 2A: one female; 3A: three females, two juveniles; 6A: ® ve males, two females, one ovigerous female, two juveniles; 13A: one male; 15A: three males, three females, three juveniles; 17A: 14 males, 14 females, three ovigerous females, 15 juveniles. Caprella santosrosai SaÂnchez-Moyano et al., 1995 (® gures 13± 16) Caprella santosrosai SaÂnchez-Moyano et al., 1995b: 197± 204, ® gures 1± 5.

Material examined. 7D: two males, two females; 14A: six males, two females, one ovigerous female, three juveniles; 15A: one male; 15D: 42 males, 22 females, ® ve ovigerous females, 17 juveniles. Remarks The record of Caprella santosrosai on the coast of Ceuta represents the ® rst for this species since its original description (SaÂnchez-Moyano et al., 1995b). Although


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Fig. 12. Caprella penantis Leach, 1814. Lateral view: a, male; b, female. Scale bar: 1 mm.

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Fig. 13.


Caprella santosrosai SaÂnchez-Moyano et al., 1995. Lateral view: a, male; b, female. Scale bar: 1 mm.


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Fig. 14. Caprella santosrosai SaÂnchez-Moyano et al., 1995. Male. a, lower lip; b, upper lip; c, maxilliped; d, left mandible; e, right mandible; f, maxilla 1; g, maxilla 2. Scale bars: 0.05 mm.

this species was fully described, we have included complete ® gures because several diŒerences have been found between specimens from southern Spain and northern Africa. The general lateral view is very similar. However the mouthparts and

696


Fig. 15. Caprella santosrosai SaÂnchez-Moyano et al., 1995. a± d, male. a, antenna 1; b, antenna 2; c, gnathopod 1; d, gnathopod 2. e, female gnathopod 2. Scale bars: a: 0.5 mm; b: 0.3 mm; c: 0.5 mm; d: 0.2 mm; e: 0.3 mm.


697

Fig. 16. Caprella santosrosai SaÂnchez-Moyano et al., 1995. a± d, male. a, pereopod 5; b, pereopod 6; c, pereopod 7; d, abdomen (ventral view). e, female abdomen (ventral view). Scale bars: a± c: 0.5 mm; d, e: 0.1 mm.

698


abdomen are diŒerent: ( 1) in specimens collected from Ceuta the outer lobe of the maxilliped has four teeth and the inner lobe three, while in the specimens from southern Spain it has three and two respectively; (2) specimens from Ceuta have no plumose seta on the outer lobe of maxilla 1, while this seta, which is rare among species of Caprella, is present in specimens from southern Spain; (3) the most remarkable diŒerences are found in the male abdomen; while specimens from Ceuta have the ® rst pair of pleopods clearly biarticulate, no distinct articulation was found in the specimens from southern Spain (SaÂnchez-Moyano et al., 1995b). Furthermore, the distal article of the ® rst pleopods is serrated on the apical margin in male specimens from Ceuta, whereas it is smooth in specimens from southern Spain. Caprella sp (belonging to the armata-group, see Krapp-Schickel and Vader, 1998) Material examined. 15A: three males, four females, one juvenile; 16A: four males, one ovigerous female; 17A: four males, three females, three juveniles; 17B: three males, one female, one ovigerous female, three juveniles; 20A: two males, one female; 22A: ® ve males, three females, two ovigerous females, three juveniles; 23A: two males, one female. Remarks The specimens studied are very similar to those described as Caprella acanthifera discrepans ( Krapp-Schickel, 1993). They are characterized by the presence of an axillary spine near the coxa of gnathopod 2. The taxa with this spine, belonging to the armata-group, are still awaiting revision ( Krapp-Schickel and Vader, 1998 ) Caprella tuberculata Bate and Westwood, 1868 (® gures 17± 20) Caprella tuberculata GueÂrin, 1836, pl. 28, ® gure 1; Goodsir, 1842: 188± 189, pl. 3, ® gures 6± 7; Bate and Westwood, 1868: 68± 70; Mayer, 1882: 56± 57, ® gures 15± 16; Chevreux and Fage, 1925: 460± 461, ® gure 437; Schellenberg, 1942: 230± 239, ® gure 199. Caprella acanthifera: Bate, 1862: 366, pl. 57, ® gure 2.

Material examined. 2B: ® ve males, six females; 15D: four males, six females, four ovigerous females, two juveniles. Diagnosis Head with a short and acute rostrum in males, and small round protuberance in females. Except the ® rst, all body pereonites with strong and numerous dorsal tubercles. Males with a pair of lateral tubercles on pereonite 5. Pereonites 1 and 2 elongated in male, pereonite 2 with plumose setae in males. Palm of the propodus of gnathopod 2 in males with large thumb-like protuberanc e de® ning the palm, and with long and dense, plumose setae. Anterior surface of basis and propodus also with plumose setae. Pereopods 5 and 6 with a pair of proximal grasping spines. Pereopod 7 with four grasping spines in males (in clusters of 2-1-1) and three in females (2-1). Material examined Male à’ from the hydroid Sertularella gayi Lamouroux (35ß 55¾ 20² N, 5ß 22¾ W ). Depth 28 metres, July 1999, coll. Jose Manuel Guerra-Garcõ Â a. Female `b’ found


Fig. 17.

699

Caprella tuberculata Bate and Westwood, 1868. Lateral view: a, male; b, female. Scale bar: 1 mm.

together with male à’ . Other specimens: four males, ® ve females collected together with male à’ ; four males, ten females and two juveniles on seaweed Dilophus spiralis Hamel (35ß 54¾ N, 5ß 16¾ 35² W ), August 1999, coll. Juan Rodrõ Â guez. Male à’ , female

700


Fig. 18. Caprella tuberculata Bate and Westwood, 1868. Male. a, lower lip; b, upper lip; c, maxilliped; d, left mandible; e, right mandible; f, maxilla 1; g, maxilla 2. Scale bars: 0.05 mm.

`b’ and another three specimens are deposited in the Museo Nacional de Ciencias Naturales de Madrid, Spain (No. MNCN 20.06/4649), the remaining specimens are in the Laboratorio de Biologõ Â a Marina, Universidad de Sevilla, Spain.


701

Fig. 19. Caprella tuberculata Bate and Westwood, 1868. a± d, male. a, antenna 1; b, antenna 2; c, gnathopod 1; d, gnathopod 2. e, female gnathopod 2. Scale bars: a,b: 0.5 mm; c: 0.2 mm; d: 0.5 mm; e: 0.2 mm.

702


Fig. 20. Caprella tuberculata Bate and Westwood, 1868. a± d, male. a, pereopod 5; b, pereopod 6; c, pereopod 7; d, abdomen (ventral view). e± f, female. e, pereopod VII; f, abdomen (ventral view). Scale bars: a± c, e: 0.5 mm; d,f: 0.05 mm.


703

Locality Ceuta, North Africa, Mediterranean (35ß 55¾ 20² N, 5ß 22¾ W; 35ß 54¾ N, 5ß 16¾ 35² W ). Redescription. Male à’ Body length. 5.9 mm. Lateral view. Head with a short, acute and curved rostrum. Except the ® rst one, all pereonites with tubercles following the formula 0-2.1-2.1-1.2.1- 2( lateral ).2.24-2.2. Pereonites 1 and 2 elongated; pereonite 2 bearing long plumose setae dorsally and ventrally. Gills. Oval, length ca twice width. Antennae. Antenna 1 with the same length as cephalon and pereonite 2 together; peduncular articles setose; ¯ agellum with 11 articles. Antenna 2 about half length of antenna 1; peduncular articles 3 and 4 carrying six pairs of long, serrated setae; ¯ agellum two-articulate, setose. Mouthparts. Upper and lower lip similar to those in Caprella ceutae n. sp. Pars incisiva and lacinia mobilis with ® ve teeth on each; left mandible with three pectinate setae and the right with two; a row of short and ® ne setae between the pectinate setae and the molar process. Maxilla 1 outer lobe with seven serrated spines distally; article 2 of palp with eight distal setae and a row of four lateral setae. Inner lobe of maxilla 2 shorter than outer, with 12 apical setae; outer lobe with nine apical setae. Inner plate of maxilliped shorter and a little wider than outer plate, with seven plumose setae and two teeth; outer plate with long simple setae and three teeth; article 2 and 3 of palp with long setae; article 4 with rows of setulae on grasping margin. Gnathopods. Merus and carpus of gnathopod 1 with row of four setae on posterior margin; propodus with a pair of proximal grasping spines; palm of propodus with a few setae; dactylus partially serrated on the inner margin. Gnathopod 2 inserted on the posterior part of the pereonite; basis one-third length of pereonite 2, with carina and several plumose setae on anterior surface; ishium, merus and carpus rounded; merus about 1.5 times larger than ischium; carpus very short, length ca one-® fth of merus; palm of propodus de® ned proximally by a large, thumb-like protuberance and distally by a round projection; between these two projections, the palm of the propodus is very concave, covered with a mixture of dense ® ne plumose and simple setae; dorsal surface of propodus also with plumose setae; dactylus with medial protuberance and plumose setae. Pereopods. Pereopods 5, 6 and 7 increasing in length respectively; palm of propodus concave; a pair of proximal grasping spines on pereopods 5, 6 and 7; on pereopod 7, two additional grasping spines, four in total. Abdomen. With a pair of appendages, a pair of lateral lobes and a single dorsal lobe; appendage two-articulate, the two articles of each appendage rounded and approximately the same size; both articles carrying three setae; distal article serrated on the apical margin; lateral lobes carrying four simple setae and dorsal lobe with two plumose setae. Penes median, slender, length ca three times width. Female `b’ Body length. 4.1 mm. Head with a short dorsal protuberance in the middle. Pereonite 1 and 2 not elongated; tubercle formula on pereonites 0-1.2.1-2-1.2.1 2-4-2.2, pereonite 5 lacking lateral tubercles; pereonite 2 without setae. Peduncular

704


articles of antenna 1 scarcely setose; ¯ agellum of antenna 1 with eight articles. Gnathopod 2 inserted on anterior half of pereonite 2; palm de® ned by two small teeth instead of thumb-like protuberance, without distal projection at the dactylar hinge; basis, propodus and dactylus without ® ne, plumose setae. Pereopod 7 propodus with three grasping spines. Anterior brood lamellae setose all round, posterior pair not setose. Abdomen with a pair of lateral lobes which carry two setae and a dorsal lobe with two plumose setae. Remarks As McCain and Steinberg (1970) pointed out, the nomenclature of this species is one of the most confused among the caprellid species. Indeed, Mayer (1882) considered that the specimens described by GueÂrin (1836) and Goodsir (1842) were not C. tuberculata. Stebbing (1888) mentioned that GueÂrin’ s C. tuberculata could be a synonym of C. scaura. The description of C. tuberculata given by GueÂrin (1836 ) is quite brief. The specimens found in Ceuta are in agreement with the description of C. tuberculata given by Bate and Westwood ( 1868) for Atlantic specimens. However, we have observed several diŒerences. Following the descriptions of Bate and Westwood (1868), Chevreux and Fage (1925) and Harrison (1944) the most striking diŒerence between C. tuberculata of Bate and Westwood and C. tuberculata found at Ceuta is the size; males of Caprella tuberculata from Ceuta do not exced 5.9 mm (although we have observed only nine adult males), while specimens from British and French coasts (Bate and Westwood, 1868) usually reach 15 mm at adulthood. Caprella tuberculata from Ceuta is also distinguished from Atlantic specimens as follows: (1) males from Ceuta have a short and round rostrum on the head while Atlantic specimens have a very short, central, dorsal spine; (2) male à’ and female `b’ from Ceuta have tubercles following the formula (0-2.1-2.1-1.2.1- 2( lateral ).2.24-2.2 in male, and 0-1.2.1-2-1.2.1-2-0-2. 2 in female). These tubercles are always present in the other specimens examined but some small tubercles may occur depending on the individuals. There is no speci® c formula for tubercles in descriptions of Atlantic specimens; (3) in C. tuberculata from Ceuta the propodus of pereopod 7 has four grasping spines in males and three in females, while there is only a single pair of grasping spines in Atlantic specimens (both male and females); (4) the posterior brood lamella are not setose on the posterior edges in females from North Africa; a setose margin is present in Atlantic specimens. Before this study, Caprella tuberculata had been found on the British and French coast but also at Santander, northern Spain (Chevreux and Fage, 1925). Marques and Bellan-Santini (1985) also reported 27 specimens of C. tuberculata from between Peniche and Arrabida (Portuguese Atlantic coast). An extensive comparative study between Atlantic individuals of C. tuberculata and the specimens of the Strait of Gibraltar would be necessary in order to elucidate whether the above diŒerences are intra-speci® c or inter-specic. Recently, a detailed comparison has been successfully conducted for the species complex Caprella acanthifera ( Krapp-Schickel and Vader, 1998) collected from Atlantic and Mediterranean waters. Pariambus typicus Kroyer, 1844 Podalirius typicus KroÈyer, 1844: 283, pl. 3, ® gure 1; Mayer, 1882: 75, ® gures 30± 31; pl. 4, ® gure 14; Mayer, 1890: 92, pl. 4, ® gures 7± 8; pl. 5, ® gures 62± 64; pl. 6, ® gure 17; Mayer, 1903: 63, pl. 7, ® gures 46± 47; pl. 10, ® gures 4± 9.


705

Pariambus typicus : Chevreux and Fage, 1925: 441, ® gure 425; McCain and Steinberg, 1970: 62.

Material examined. I: four males, eight females; III: one male; IV: 13 males, 36 females, 12 juveniles, V: three males, three females, VI: three males, two females; VII: two males, ® ve females, one juvenile; VIII: one male, one female, one ovigerous female; IX: one male; X: one male, two females. Pedoculina garciagomezi SaÂnchez-Moyano et al., 1995 Pedoculina garciagomezi SaÂnchez-Moyano et al., 1995a: 419 ± 427, ® gures 2± 6.

Material examined. 16A: one male; 18D: one male. Phtisica marina Slabber, 1769 Phtisica marina Slabber, 1769: 77, pl. 10; Chevreux and Fage, 1925: 434, ® gure 422; Fiorencis, 1940: 11, ® gure 1, pl. 1, ® gures 1± 2; Costa, 1960: 99; McCain, 1968: 91, ® gures 46± 47; McCain and Steinberg, 1970: 65. Proto brunneovittata: Heller, 1879: 231; Haller, 1880: 339, pl. 22, ® gures 19± 22. Proto pedata: Haller, 1879: 230; Haller, 1880: 398. Proto ventricosa: Mayer, 1882: 22, pl. 1, ® gure 1; pl. 3, ® gures 16± 29; pl. 4: ® gures 12± 13; pl. 5: ® gures 1± 5; Mayer, 1890: 12, pl.3, ® gures 4± 6; pl. 5, ® gures 3± 6; pl. 6, ® gure 1; pl. 7, ® gure 1; Mayer, 1903: 20, pl. 6, ® gure 23; Monterosso, 1915: 3.

Material examined. 1A: nine males, one female; 1C: two males, ® ve females; 2A: two males, one female, one juvenile; 2B: ® ve males, seven females, two ovigerous females, three juveniles; 3A: ® ve males, three females, one ovigerous female, seven juveniles; 5A: two males, one female, one ovigerous female; 7A: two males; 7B: one male, two females; 8A: one ovigerous female; 9A: four males, three females, one ovigerous female, two juveniles; 10A: one male; 11A: ten males, four females, three juveniles; 12A: one male, two ovigerous females, one juvenile; 12B: four males; 13A: one juvenile; 14A: two males, one female; 15A: one male; 15B: four males, one female, one ovigerous female, one juvenile; 15D: two males, one female, three juveniles; 16A: one male, one female, one juvenile; 17B: ® ve males, one female; 17C: ten males, four females, four ovigerous females, four juveniles; 18C: two males, one female; 19A: two males, one female, one juvenile; 20A: two males, two females; 21A: two males; 22A: ® ve males, three females, one ovigerous female, one juvenile; IV: one male; VI: three males, three females, three juveniles; VII: four males, one female. Pseudoprotella inermis Chevreux, 1927 Pseudoprotella inermis Chevreux, 1927: 135, pl. 14, ® gures 3± 5; McCain and Steinberg, 1970: 72; Guerra-Garcõ Â a and Takeuchi, 2000: 980± 988, ® gures 2± 5.

Material examined. 15D: seven males, two females, four juveniles. Pseudoprotella phasma (Montagu, 1804) Cancer Phasma Montagu, 1804: 66, pl. 6, ® gure 3. Caprella quadrispinis: Grube, 1864: 63. Protella phasma: Mayer, 1882: 29, pl. 1, ® gure 2; pl. 4, ® gures 1± 8, ® gures 34± 37; pl. 5, ® gures 19± 21. Pseudoprotella phasma: Chevreux and Fage, 1925: 437 ± 439, ® gure 423; Cavedini, 1982: 527.

Material examined. 1A: three males, three females; 1C: one female; 1D: four males, three females, two ovigerous females, one juvenile; 2B: 26 males, 20 females, seven ovigerous females, 22 juveniles; 5A: eight males, ® ve females, one ovigerous

706


female, ten juveniles; 7A: one male, one female, one ovigerous female, one juvenile; 7B: two males, one female, one juvenile; 7C: one male, one female, one juvenile; 12B: one male, one female, one juvenile; 14A: one ovigerous female; 15B: one male, one female, one juvenile; 15D: seven males, six females, one juvenile; 17B: three males, two females, one female carrying juveniles, 17C: nine males, nine females, two ovigerous females, eight juveniles; 18C: six males, two females; 19D: ® ve males, ® ve females, one ovigerous female, four juveniles; 20A: two males; 21A: one male; 22A: one male; 23A: one male, two females carrying juveniles. Key to species of Caprella from Ceuta The key is based primarily on gnathopod 2 of adult males, following Takeuchi (1995 ). 1 ±

Basis of gnathopod 2 clearly shorter than one-third of pereonite 2 Basis of gnathopod 2 longer than one-third of pereonite 2 . .

. .

. .

. .

. .

. .

2 5

2 ±

Propodus of gnathopod 2 profusely setose . Propodus of gnathopod 2 scarcely setose .

. .

. .

. .

. .

. .

3 4

3

Propodus of gnathopod 2 entirely covered with ® ne plumose setae. Articles 2 and 3 of antenna 1 with dense plumose setae on the posterior margin . . . C. fretensis Propodus of gnathopod 2 profusely setose only proximally. Only article 3 of antenna 1 with dense setae posteriorly . . . . . . . . C. ceutae n. sp (® gures 2± 5)

±

. .

. .

. .

. .

. .

. .

4

Head without rostrum. Pereopods without grasping spines . C. danilevskii (® gure 6) Head with rostrum. Pereopods with grasping spines . . C. liparotensis (® gures 8± 11 )

5

Antennae 2 with short setae posteriorly Antennae 2 with long setae posteriorly .

. .

. .

. .

. .

. .

. .

. .

. .

. .

6 ±

Body with dorsal tubercles . Body without dorsal tubercles

. .

. .

. .

. .

. .

. .

. .

. .

. .

. .

. .

. C. acanthifera . . . . 7

7 ±

Body with a few rounded humps Body smooth . . . . .

. .

. .

. .

. .

. .

. .

. .

. .

. .

. .

. C. cavediniae . . . . 8

8

Propodus of gnathopod 2 round with dense, long setae dorsally; basis about half of pereonite 2. . . . . . . . . . . . . . . . . . . C. hirsuta

±

Propodus of gnathopod 2 with sparse, short setae dorsally; basis as long as pereonite 2 . . . . . . . . . . . . . . . . . . . . C. grandiman a 9 ±

Pereonite 1 shorter than head Pereonite 1 longer than head

± ±

. .

. .

. .

. .

. .

. .

. .

10 Gnathopod 2 with distal poison tooth . . ± Gnathopod 2 with proximal poison tooth .

. .

. .

. .

. .

. .

.

11 All the body pereonites with dorsal acute projections . Body pereonites with tubercles . . . . . . .

. .

. .

±

. .

. .

. .

.

. .

. .

. .

. .

. .

. .

. .

6 9

. 10 . 11

. . C. dilatata C. penantis (® gure 12 ) C. erethizon (® gure 7) . . . . . 12

12 Head with a central dorsal projection. Propodus of gnathopod 2 setose on posterior surface. Acute ventral projections on pereonites 2± 4 . C. santosrosai (® gures 13± 16 ) ± Head with a short acute rostrum. Propodus of gnathopod 2 setose on anterior and posterior surface. Acute ventral projections lacking . C. tuberculata (® gures 17± 20 )

Discussion Ceuta is located on the North African side of the Strait of Gibraltar. The Strait of Gibraltar is a very important geographical-geologica l formation formed in the ® nal phases of the Pliocene period. It is the boundary for the Mediterranean region (to the east), the Lusitanian region (to the northeast ) and the Mauretanian region


707

(to the southeast). The Strait is a zoogeographical area, especially from the point of view of the interchange of the species between the Atlantic and the Mediterranean, and the European and African faunas. Thus, the Strait has attracted the attention of marine taxonomists in latter years and several biogeographica l studies have been published (e.g. bryozoans: LoÂpez de la Cuadra and Garcõ Â a-GoÂ mez, 1995; sponges: Carballo et al., 1997; ascidians: Naranjo et al., 1998; molluscs: Gofas, 1998). A recent cladistic analysis by Bellan-Santini and RuŒo (1998) indicates that the Mediterranean and Atlantic fauna of amphipods are very close and that a large proportion of Mediterranean amphipods could be of Atlantic origin. Recently, the benthic Gammaridea fauna of Algeciras Bay (Iberian side of the Strait of Gibraltar) has been studied (Conradi and LoÂpez-GonzaÂ lez, 1999). In this case, all species collected, except Urothoe hesperiae which was described as a new species (Conradi et al. 1995), had been found in Mediterranean waters in previous studies. Thus, Algeciras Bay can be considered a typical Mediterranean locality despite being situated within the Strait of Gibraltar. In the Mediterranean Sea, 33 species of caprellids have been recorded so far including the present study (table 2, ® gure 21). Of these species, 13 (39.4%) have been collected only in Mediterranean waters and they can be considered as Mediterranean endemic. On the coast of Ceuta, which is only about 20 kilometres long we have collected 19 of these 33 species; four of them (Caprella ceutae, Caprella santosrosai, Pedoculina garciagomezi and Pseudoprotella inermis) are, so far, endemic to the Strait of Gibraltar. Thus, 30.8% of Mediterranean endemic species are endemic to the Strait of Gibraltar. Caprella fretensis, C. erethizon and C. tuberculata had previously been collected only on Atlantic coasts (Chevreux and Fage, 1925, Harrison, 1944, Marques and Bellan Santini, 1985). With the present work the distributions of these species are extended to Mediterranean waters. The species Caprella santosrosai and Pedoculina garciagomezi are recorded for the ® rst time on the coast of north Africa, demostrating that these species inhabit both sides of the Strait of Gibraltar. The percentage of caprellid endemism in the Mediterranean ( 39.4%) is only a little higher than the 37% reported by Bellan-Santini and RuŒo (1998) for caprellids and gammarids combined. Both values are higher than the 26.6% calculated by Fredj et al. (1992) for all of the Mediterranean fauna taken together. As indicated by Bellan-Santini and RuŒo (1998), further researches along the Atlantic coast of North Africa and the Iberian Peninsula would likely reduce the number of amphipods that are considered endemic to the Mediterranean. For example, Caprella hirsuta and C. grandimana, considered as Mediterranean endemics in Krapp-Schickel ( 1993), have been recently reported on the Atlantic african coasts from Cape Spartel to Cape Blanc (Bellan-Santini and RuŒo, 1998). A similar change in biogeographic distribution was found for Caprella rapax Mayer, 1890, which was collected recently on the Atlantic Iberian coast ( Bellan-Santini and RuŒo, 1998). Although Parvipalpus major Carausu, 1941 was considered as an endemic species by Bellan-Santini and RuŒo (1998), specimens of this species were collected in the Bay of Biscay (Laubitz and Sorbe, 1996) so this species also extends to Atlantic waters and is not a Mediterranean endemic. Nevertheless, more extensive researches are necessary to expand our understanding of the biogeography of the caprellid fauna of African coasts, not only northern Africa but also Atlantic coasts of Africa, and especially the African coasts of the Indian Ocean. The caprellid fauna on the Indian coast has a special taxonomic

708

J. M. Guerra-GarcÌá and I. Takeuchi Table 2.

Name of species

Caprellids cited in Mediterranean waters. ME

SGE

Caprella acanthifera* Caprella andreae Caprella cavediniae* 1

1

Caprella ceutae, n. sp.* Caprella danilevskii*

Caprella dilatata* Caprella equilibra Caprella erethizon* Caprella fretensis* Caprella grandiman a* Caprella hirsuta*

1

Caprella lilliput Caprella linearis Caprella liparotensis*

1

Caprella mitis Caprella penantis* Caprella rapax Caprella santosrosai* Caprella sp (armata-group)* Caprella telarpax Caprella tuberculata* Deutella shieckei Liropus elongatus Liropus minimus Pariambus typicus*

Parvipalpus linea Parvipalpus major Pedoculina bacescui Pedoculina garciagomezi* Phtisica marina*

1

1 1 1 1 1

1

1

1 1

Presence on North African coast Algeria: Cherchell, Bou Ismail (Bakalem and Dauvin, 1995); Morocco (Bellan-Santini and RuŒo, 1998); Ceuta (Present study) Algeria (McCain, 1968 ) Ceuta (Present study) (see Krapp-Schickel and Vader, 1998) Ceuta (present study) Algeria: Alger, Cherchell (Chevreux and Fage, 1925); Algeria: Alger, Bou Ismail (Bakalem and Dauvin, 1995); Morocco (Bellan-Santini and RuŒo, 1998), Ceuta (present study) Algeria (McCain and Steinberg, 1970), Morocco (Bellan-Santini and RuŒo, 1998), Ceuta (present study) Egypt: Port Said (Schellenberg, 1928); Algeria: Cherchell, Bou Ismail (Bakalem and Dauvin, 1995 ) Ceuta (present study) Ceuta (present study) Morocco (Bellan-Santini and RuŒo, 1998); Ceuta (present study) Tunisia: La Galite; Algeria: Cherchell (Chevreux and Fage, 1925); Morocco (BellanSantini and RuŒo, 1998); Ceuta (present study) Not collected on North African coast Algeria: Bou Ismail (Bakalem and Dauvin, 1995 ) Egypt: Abu Qir (Schellenberg, 1936); Algeria: Cherchell (Chevreux and Fage, 1925); Morocco (Bellan-Santini and RuŒo, 1998); Ceuta (present study) Algeria (Bakelem and Dauvin, 1995) Egypt: Abu Qir (Schellenberg, 1936); Algeria: Alger (Mayer, 1890); Morocco (Bellan-Santini and RuŒo, 1998); Ceuta (present study) Not collected at North African coast Ceuta (present study) Ceuta (present study) Not collected at North African coast Ceuta (present study) Not collected at North African coast Algeria: Alger (Bakalem and Dauvin, 1995) Not collected at North African coast Algeria: Alger (Chevreux and Fage, 1925); Algeria: Bou Ismail, Alger (Bakalem and Dauvin, 1995); Morocco (Bellan-Santini and RuŒo, 1998); Ceuta (present study) Not collected at North African coast Not collected at North African coast Not collected at North African coast Ceuta (present study) Algeria: Bou Ismail, Alger, Bejaia (Bakalem and Dauvin, 1995); Ceuta (present study)

The Caprellidea from Ceuta, North Africa Table 2. Name of species

ME

Pseudolirius kroyeri

1

Pseudoprotella inermis*

1

Pseudoprotella phasma*

SGE

1

709

(Continued ). Presence on North African coast Algeria: Bou Ismail, Alger, Bejaia, Annaba (Bakalem and Dauvin, 1995) Spain: CaÂdiz (Chevreux, 1927); Ceuta (GuerraGarcõ Â a and Takeuchi, 2000; present study) Egypt: Abu Qir (Schellenberg, 1936); Algeria: Bou Ismail (Bakalem and Dauvin, 1995); Morocco (Bellan-Santini and RuŒo, 1998); Ceuta (present study)

Sources: Krapp-Schickel (1993 ) for all species except Caprella cavediniae ( Krapp-Schickel and Vader, 1998), Caprella linearis (Bakalem and Dauvin, 1995), Caprella santosrosai (SaÂnchez-Moyano et al., 1995b ), Pedoculina garciagomezi (SaÂnchez-Moyano et al., 1995a), Pseudoprotella inermis (Chevreux, 1927; Guerra-Garcõ Â a and Takeuchi, 2000), Caprella ceutae, n. sp. (present study) and the atlantic species C. erethizon, C. fretensis and C. tuberculata (present study). ME: Mediterranean endemic, SGE: Strait of Gibraltar endemic. Presence on North African coast is indicated. The asterisk (*) after species names indicates that specimens of these species have been found on the coast of Ceuta. More detailed information about biogeographical distribution of the species is included in Bellan-Santini and RuŒo (1998).

Fig. 21. Number of species of the Caprellidea in North Atlantic and Mediterranean areas.

interest since it is situated between distribution centres of the Atlantic and Paci® c ( Takeuchi, 1993). Among the species of Caprella from Ceuta we can diŒerentiate a group of species by the short length of the gnathopod 2 basis, i.e., C. danilevskii, C. liparotensis, C. fretensis and C. ceutae. Clinging behaviour has been studied in C. danilevskii by Takeuchi and Hirano (1995), who report that the short basis in this species allows the parallel posture to be adopted more easily. The species with a longer gnathopod 2 basis can be separated into two subgroups. One is composed of species which have no long setae on antenna 2, i.e. C. acanthifera, C. cavediniae, C. hirsuta and C. grandimana. The other two species, Caprella penantis

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and C. dilatata, develop a setose ventral surface of antenna 2. These two species can be easily distinguished from the remaining species of Caprella from Ceuta in that they have a very short pereonite 1 of the cephalon. Caprella penantis has been recorded under several species or subspecies names from the temperate regions of the world (McCain and Steinberg, 1970) and there is need of further studies to determine its nomenclatural status at each locality (McCain, 1968; Laubitz, 1972; Takeuchi and Hirano, 1995). As well as C. danilevskii, C. penantis also displays the `parallel posture’ ( Takeuchi and Hirano, 1995). The remaining species of Caprella from Ceuta, C. erethizon, C. tuberculata and C. santosrosai can be easily diŒerentiated by ornamental characteristics (tubercles and acute projections) along their bodies. These three species seem to be very close, sharing morphological characteristics. Probably C. santosrosa i known only in the Strait of Gibraltar so far, will soon be found on Atlantic coasts living together with C. erethizon and C. tuberculata. We also consider it possible that this species could be the Mediterranean vicariant of the Atlantic species Caprella septentrionalis KroÈyer. Caprella tuberculata, C. erethizon, C. santosrosa i and C. ceutae n. sp. have been found together on similar substrata, and at localities on the littoral of Ceuta with similar ecological characteristics. How can they coexist and avoid competition? Perhaps they have diŒerent life-cycles through the year. It would be interesting to undertake rearing experiments in the laboratory with these species using Takeuchi’s methodology ( Takeuchi and Hirano, 1991, 1992) and to study the clinging behaviour on the substratum. The short gnathopod basis in C. ceutae could enable it to adopt a more parallel posture, categorized by Takeuchi and Hirano (1995). These four species have, until now, a restricted distribution. Caprella ceutae could have evolved from the ancestor of the cosmopolitan C. equilibra, adapting to particular ecological characteristics present in the Strait of Gibraltar. Acknowledgements We express our thanks to CompanÄõ Â a del Mar and Club Calypso for assistance in the ® eld. The senior author (JMGG ) thanks Dr. JoseÂ Carlos Garcõ Â a-GoÂmez, director of the research project `Biodiversidad y Medio Ambiente Ceutõ Â ’ for enabling the study in Ceuta and Asamblea de Ceuta and a grant, `Programa de FormacioÂn de Profesorado Universitario y Personal Investigador’, from the Ministry of Education and Culture of Spain for ® nancial support. The work was completed at the Otsuchi Marine Research Center. The work was partially supported by the Cooperative International Research on Marine and Coastal Environment by the United Nations University, Ocean Research Institute, The University of Tokyo and Iwate Prefecture Government. References Bakalem, A. and Dauvin, J. C., 1995, Inventaire des crustaceÂs Amphiphodes (Gammaridea, Caprellideaa, Hyperiidea) des coÃtes d’AlgeÂrie: essai de syntheÁse, MeÂ sogeÂ e (Bulletin du Museum d’ Histoire Naturelle de Marseille), 54, 49± 61. Bate, C. S., 1856, On the British Edriophthalma. Part I. The Amphipoda, Report of the British Association for the Advancement of Science, 25, 18± 62. Bate, C. S., 1862, Catalogue of the Specimens of Amphipodou s Crustacea in the Collection of the British Museum (London: British Museum), 399 pp. Bate, C. S. and Westwood, J. O., 1868, Caprellidae, A History of the British Sessile-eyed Crustacea, 2, 68± 70. Bellan-Santini, D. and Ruffo, S., 1998, Faunistics and Zoogeography, in S. RuŒo (ed.)


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