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NATURAL HISTORY NOTES CAUDATA — SALAMANDERS DESMOGNATHUS FUSCUS FUSCUS (Northern Dusky Salamander). LARVAL ATTENDANCE. Desmognathus fuscus is a semi-aquatic plethodontid salamander that oviposits in or near water, where aquatic larvae develop. Attendance of eggs by females is well-documented as a vital behavior for successful reproduction in this species; clutches are rarely abandoned, as this frequently results in complete failure (Hom 1987. Copeia 1987:768–777). Female attendance of eggs is expected in plethodontid species that can oviposit terrestrially (Wells. 2007. The Ecology and Behavior of Amphibians. University of Chicago Press, Chicago, Illinois. 1148 pp.). When offspring are direct-developing, such as in Plethodon cinereus (Eastern Redbacked Salamander), females have been observed remaining in nest sites with juveniles for weeks (Petranka 1998. Salamanders of the United States and Canada. Smithsonian Institution Press, Washington and London. 587 pp.). In species with aquatic larvae like D. fuscus, females may remain in terrestrial nests for a few days after clutches hatch, before the larvae move to water (Juterbock 1987. Herpetologica 43:361–368; Wells 2007, op. cit). This note expands the time period and role of attendance to aquatic larvae in Plethodontids that can oviposit terrestrially, with further observations of female D. fuscus and their larvae remaining in nest sites. Two nests of D. fuscus were observed along the dry headwaters of Bower’s Spring, Worcester Co., Massachusetts, USA (42.4673°N, 71.6051°W, WGS84). The first nest was found on 4 October 2014, as the clutch was hatching, under a small moss mat overhanging the damp run bed. From 7–9 October 2014, the female and at least 10 larvae were visible in this nest each day,
generally in close contact. One larva was unearthed in the mud below the nest on 9 October 2014. On 10 October 2014 the female was barely responsive and dry to the touch; 8 larvae remained in the nest, but appeared to be dispersing rather than grouped as previously observed. A second nest was found slightly downstream on 9 October 2014, under a small log in the mud of the stream bed. When uncovered, a female was standing over the majority of her larvae, facing a Eurycea bislineata (Northern Twolined Salamander) at the back of the nest (Fig. 1). Thirteen larvae were counted after both adult salamanders fled. By 10 October 2014 the female had returned, and 13 larvae were again observed. On the morning of 11 October 2014, both females from the above observations were absent from their nests. No larvae remained in the first nest; 13 were seen in the second, about half of which had begun to burrow into the mud. Female plethodontids may coil around eggs laid terrestrially, to help prevent desiccation (Wells 2007, op. cit.). The preceding observations are consistent with the possibility that females may also use physical contact to help prevent the desiccation of aquatic larvae hatched in terrestrial nests, when water is not available. Larval attendance may also be exhibited by D. fuscus nesting in aquatic sites. On 29 October 2014, in the headwaters of an unnamed hillside spring 2.4 km from Bower’s Spring (42.4645°N, 71.5759°W; WGS84), a female was found under a rock in a few cm of water with an aquatic larva (total length = 2.4 cm) adhered dorsolaterally above her rear leg. Another adult D. fuscus was present in the water at the edge of the cover rock. This observation, in addition to adult E. bislineata frequently seen approaching D. fuscus larvae at Bower’s Spring, are consistent with the possible anti-predatory function of larval attendance. The observations in this note extend the period of aquatic larval parental care observed in D. fuscus from a few days to over one week, in the absence of water. The scope of larval attendance is also expanded to potentially include aquatic nest sites (Wells 2007. op. cit). Repeated observations of the brooding of aquatic larvae are useful to inform and motivate future studies. JENNIE WILLIAMS (e-mail:
[email protected]), 21 Aldersey St. #4, Somerville, Massachusetts 02143, US
Fig. 1. Desmognathus fuscus with developing larvae.
DESMOGNATHUS QUADRAMACULATUS (Black-bellied Salamander). PREDATION. Trout are known predators on the various life stages of salamanders (Petranka 1998. Salamanders of the United States and Canada. Smithsonian Inst. Press, Washington DC. 587 pp.) and, in some cases, there are strong interactions between trout species and salamanders that can influence co-occurrence within streams (Resetarits 1997. Ecology 72:1782–1793). Most literature reporting these interactions focus on Oncorhynchus mykiss (Rainbow Trout) and two salamander species (e.g., Ambystoma macrodactylum and A. gracile, reviewed by Dunham et al. 2004. Fisheries 29:18–26) from the Western United States. Herpetological Review 46(2), 2015
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Fig 1. Polyembryonic egg of Hemidactylium scutatum.
Fig. 1. Predation of an adult salamander Desmognathus quadramaculatus by an adult Salvelinus fontinalis.
On the afternoon of 08 October 2014, an adult Salvelinus fontinalis (Brook Trout; total length = 19.69 cm) was captured via electrofishing in Left Prong Hampton Creek in Carter Co., Tennessee, USA (36.1467°N, 82.0491°W, WGS84; 983 m elev.) with an adult Desmognathus quadramaculatus (total length = 10.80 cm) protruding from its mouth (Fig. 1). The salamander was desceased (photo voucher APSU 19530) and its tail was partially digested; therefore, the predation event preceeded our disturbance of the aquatic habitat and this event should be considered natural. This report is the first confirmed predation on D. quadramaculatus by S. fontinalis (Petranka 1998, op. cit.). However, because the elevational distribution of D. quadramaculatus (341–1829 m elev.; Dodd 2004. The Amphibians of Great Smoky Mountains National Park. University of Tennessee Press, Knoxville, Tennessee. 283 pp.) overlaps with both S. fontinalis and the introduced O. mykiss in the southern Appalachian Mountains, our finding is probably more common than reported in the literature. JOSHUA R. ENNEN (e-mail:
[email protected]), BERNIE R. KUHAJDA, KATHLINA F. ALFORD, and SARAH C. HAZZARD, 201 Chestnut Street, Tennessee Aquarium Conservation Institute, Chattanooga, Tennessee 37402, USA.
HEMIDACTYLIUM SCUTATUM (Four-toed Salamander). POLYEMBRYONY. Polyembryony in amphibians has been examined in vitro, but rarely observed in situ, especially in caudates. Natural observations of twinning in Ambystoma tigrinum, as three polyembryonic eggs, each containing two embryos, were observed from 1987–1988 (Lindberg 1995. Herpetol. Rev. 26:142). However,
polyembryony has not been documented in Plethodontid salamanders. We report the first known observation of polyembryony in Plethodontid salamanders and specifically from Hemidactylium scutatum. From 2007–2012 we located 369 nests of H. scutatum and examined 14,379 eggs from a site in Sullivan Co., Tennessee (36.52266°N, 82.11073°W; WGS84). On 09 April 2011 we found a joint nest with a single female (SVL = 38.7 mm; total length = 88.6 mm) guarding eggs in which one egg had two embryos (Fig. 1) while the remaining 64 eggs in the nest, and all other eggs located at the study site, contained a single embryo. At the time of discovery both embryos appeared to be at Harrison stage 36 (Harrison 1969. Organization and Development of the Embryo. Yale University Press, New Haven, Connecticut. 290 pp.). The polyembryonic embryos differed in size during development and immediately after hatching (on 10 May 2011), when one embryo was 12.7 mm total length and the other was 13.8 mm. Mean total length from a sample of 12 H. scutatum larvae, randomly selected from ~600 larvae collected from 56 nests in 2011, was 13.3 mm (range: 12.1–16.0 mm). All eggs within the nest containing the H. scutatum polyembryonic egg hatched within one hour of a rain event. Our observations of H. scutatum hatching during this project indicated that most (> 90%) eggs from the same nest hatched within one hour of the first egg hatching. Both larvae from the polyembryonic egg were placed in mesocosm pools after hatching and no additional observations were made. M. KEVIN HAMED, Virginia Highlands Community College, P.O. Box 828, Abingdon, Virginia 24212, USA (e-mail:
[email protected]); MATTHEW J. GRAY, Department of Forestry, Wildlife and Fisheries, Institute of Agriculture, University of Tennessee, 274 Ellington Plant Sciences Building, Knoxville, Tennessee 37996, USA; THOMAS F. LAUGLIN, Department of Biological Sciences, East Tennessee State University, Box 70703, Johnson City, Tennessee 37614, USA.
SIREN INTERMEDIA (Lesser Siren). MASS AESTIVATION AND ARTIFICIAL HIBERNACULA. Siren intermedia is a large (max. recorded length 686 mm) eel-like aquatic salamander distributed across the southeastern United States westward to eastern Texas and the lower Rio Grande Valley and northward through the Mississippi Valley to Illinois and Indiana (Martof 1973. Cat. Amer. Amphib. Rept. 127:1–3; Conant and Collins 1998. A Field Guide to Reptiles and Amphibians: Eastern and Central North America. 3rd ed. Houghton Mifflin Co., Boston, Massachusetts. 616 pp.). Siren
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