Philipp. Scient. 49: 97–101 © 2012, University of San Carlos Press
Notes and Information
The goby Trypauchenopsis intermedia Volz 1903 (Gobiidae) from the Philippines
Abner A. Bucol*, Ely L. Alcala and Angel C. Alcala Silliman University Angelo King Center for Research and Environmental Management, 6200 Dumaguete City, Philippines *Corresponding author. Email:
[email protected]
ABSTRACT The cryptic Indo-Pacific goby Trypauchenopsis intermedia Volz 1903 caught from the muddy estuary of Jalaur River in Iloilo, Panay Island is reported for the first time as a new country record for the Philippines. A brief description and a photograph of the only specimen are also presented. Keywords: estuary, Trypauchenopsis, Gobiidae, Panay Island, Philippines
INTRODUCTION The Indo-Pacific gobiid species Trypauchenopsis intermedia was described by Volz (1903) from Sumatra, Indonesia. It has been referred to as Brachyamblyopus intermedius (E. Murdy in Eschmeyer 2009; Froese & Pauly 2010). The species has a wide but patchy distribution in the IndoPacific, from South Africa, Indonesia, China and the Ryukyu Islands of Japan (Kottelat et al. 1993, Froese & Pauly 2010; E. Murdy 2011 pers comm). However, it has not yet been reported from the Philippines despite of earlier work on gobies (e.g., Herre 1927, 1940, Roxas & Ablan 1940). Its cryptic behavior may have caused the species to not be sampled during the early collecting trips in the Philippines. This short paper reports the presence of this species in the Philippines and also presents a brief description based on the only available specimen.
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MATERIALS AND METHODS In October 29, 2009, a single individual was incidentally captured in the muddy estuary of Jalaur River, Iloilo in Panay Island using a scoop net intended to capture the mudskipper Scartelaos histophorus during the lowest tide. The exposed substratum was soft, dominated by mud, about 0.5 to 1.0 m depth. Salinity of the water ranged from 3 to 15 ppt during the sampling (October 29, 2011). The specimen was preserved in 10% formalin and later deposited at the Rodolfo B. Gonzales Museum of Natural History in Silliman University (SURBG), Dumaguete City. RESULTS AND DISCUSSION At first glance, the species can be confused with Caragobius urolepis (Bleeker 1852) in having elongated body, smooth head and absence of a pouch-like cavity at the dorsal margin of the operculum (Larson & Murdy 2001) and cephalic sensory canals and pores (Murdy & Shibukawa 2003) but closer examination of its head reveals several barbel-like processes arranged (in single and double rows), which are probably extensions of the sensory papillae. T. intermedia is also similar to Brachyamblyopus olivaceus, a synonym of C. urolepis (Murdy & Shibukawa 2003), described by Herre (1927) from La Libertad Negros Oriental and Guimaras Strait in the slenderness of its body and in having dorsal and anal fins continuous with the caudal fin. However, based on Herre’s illustration, we concur with Murdy & Shibukawa (2003). Our specimen differs from C. urolepis and all the others in the Trypauchen group in lacking scales on the body (Murdy & Shibukawa 2003, Murdy 2006, 2008a, b). This goby (Fig. 1) is expected to be found in the Philippine waters given the proximity of the type locality (Banjun asin, Palembag, Sumatra, Indonesia) in the Philippines. However, it is surprising that it has not been captured elsewhere in the country prior to our collecting trip. The probable reason might be its cryptic habit, habitat preference (soft, muddy substrate) and the collection method used. It may have been missed by rotenone sampling because it can penetrate the muddy substrate.
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Figure 1. Lateral view of the preserved specimen of Trypauchenopsis intermedia (SURBG 10025)
Description The following counts and measurements (in mm) are based on the only available specimen (SURBG 10025): total length 54.5; head length 6.0; head width 4.0; snout 1.5; pre-anal length 18.5; interorbital distance 1.0; pectoral fin 5 (base 2.0, rayed 3.0); pelvic 6.5; tail 21; body depth at level of vent 4.0. lateral line pores 25 total (10 before vent, 15 towards tail); dorsal fin origin at level of tip of pectorals; pectoral rays 17; frenum rays 29-30; dorsal rays 29; caudal rays 15; anal rays about 25 (partly damaged near tail). Eyes small, positioned dorsally. Teeth minute in two series of both upper and lower lips; barbel-like processes on cheek/mandible and lower chin and near groove in upper lip. Coloration when fresh generally light brownish to reddish. In preservative, the specimen appears dark brown to black especially on lateral side of head and base of caudal fin. Base of pectoral fins pale. Body with minute dark spots, especially around the lateral line pores. Fins translucent, except the caudal rays. The anterior part of belly silvery white and the posterior part yellow, indicative of the location of the gas bladder and mature gonads, respectively. Future investigations may provide insight as to the distribution of this species in the Philippines. The use of indigenous gears and the timing of collection may help reveal the species in other estuarine areas, such as in the nearby Negros and Mindanao Islands. ACKNOWLEDGMENTS We thank Dr. Edward O. Murdy (National Science Foundation, USA) for confirming the identity of Trypauchenopsis intermedia. Our survey in Jalaur River, Iloilo was funded by the Commission on Higher Education through the Grant-In-Aid (GIA) Program. Dr. Reynaldo
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Dusaran served as the project leader of the Jalaur River Assessment Project. Drs. A.C. Alcala and Orencio D. Lachica (former Director and Asst. Director of Silliman University-CHED Zonal Research Center) are also acknowledged for their support of the project. We also thank the two anonymous reviewers for the helpful comments and suggestions that greatly improved the manuscript. A. Bucol has been supported by grants from the Dr. Walter C. Brown Scholarship and del Carmen Scholarship administered by SUAKCREM which enabled him to pursue the publication of this paper.
LITERATURE CITED Eschmeyer W. 2009. Catalog of Fishes. California Academy of Sciences. www.calacademy.org (accessed: 21 Nov 2009). Froese R, Pauly D. 2010. FishBase. Electronic database accessible at http://www.fishbase.org.search. (accessed: 10 Oct 2010). Herre AWCT. 1927. Gobies from the Philippines and the China Sea. The Philippine Bureau of Science Monographic Publications on Fishes, pp. 5-352. Herre AWCT. 1940. Notes on the fishes in the Zoological Museum of Stanford University, VII, New and rare Philippine gobies from the Herre 19361937 Oriental Expedition and in the Collection of the Bureau of Science. Philippine Journal of Science 72(4): 357-367. Kottelat M, Whitten AJ, KArtikasari SN, Wirjoatmodjo S. 1993. Freshwater Fishes of Western Indonesia and Sulawesi. Periplus Editions, Hongkong. Larson HK, Murdy EO. 2001. Gobiidae. Gobies. Pp. 3578-3603. In: Carpenter, K.E. and Niem, V.H. (eds.) FAO Species Identification Guide For Fishery Purposes. The Living Marine Resources of the Western Central Pacific. Volume 6. Bony fishes part 4 (Labridae to Latimeriidae). FAO, Rome. Murdy EO, Shibukawa K. 2003. A revision of the Indo-Pacific fish genus Caragobius (Gobiidae: Amblyopinae). Zootaxa 301: 1–12.
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Murdy EO. 2006. A revision of the gobiid fish genus Trypauchen (Gobiidae: Amblyopinae). Zootaxa 1343: 55–68. Murdy EO. 2008a. Trypauchenichthys larsonae, a new species of amblyopine goby from Australia (Gobiidae: Amblyopinae) with a key to the species in the genus. aqua, International Journal of Ichthyology 14(2): 59-68. Murdy EO. 2008b. Paratrypauchen, a new genus for Trypauchen microcephalus Bleeker, 1860, (Perciformes: Gobiidae: Amblyopinae) with a redescription of Ctenotrypauchen chinensis Steindachner, 1867, and a key to ‘Trypauchen’ group genera. aqua, International Journal of Ichthyology 14(3): 115-128. Roxas HA, Ablan GL. 1940. New Philippine gobioid fishes. Philippine Journal of Science 73(3): 301-311. Volz, W. 1903. Neue Fische aus Sumatra. Zoologischer Anzeiger 26 (703): 553559.
