AUSTRALIAN BIODIVERSITY RECORD - Calodema

Australian Biodiversity Record, 2007 (8): 1-124Toxicity: This species rarely attempts to bite, but caution should nevertheless be exerted,because its venom is likely highly toxic to humans. Urgent medical attention should always besought in the event of a bite from this species.Survival Status: Protected under the WA Wildlife Conservation Act 1950 (as amended). Listedas a Marine Protected Species under the Australian Environmental Protection andBiodiversity Conservation Act (1999). Probably not under threat, but its restricted distributionin Australian waters could potentially make it vulnerable in some parts of its range.Etymology: The name 'apraefrontalis' means 'without prefrontal', in reference to the headshields of this species.Smithohydrophis foliosquama comb. nov. (Smith, 1926)Aipysurus foliosquama Smith, M.A. (1926). Monogr. Sea Snakes. (Hydrophiidae). [p. 22, figs11-12 pl. 2 fig. 3]. Type data: holotype BMNH 1946.1.1.96. Type locality: Ashmore Reefs,Australia.Description: This is quite a small species of sea snake, in which the body-form is moderatelyelongate, the head small with a pointed snout, and the head is barely distinct from the neck.Overall the base body colour is usually purplish, with some being more dark olive-brown.There is a series of narrow or broad, light olive-brown transverse bands, which tend to be lessdistinct dorsally, and most prominent laterally. In some specimens two narrow light bandsmay be very close together with a narrow darker interspace of purplish-brown, followed by abroader interspace of darker purplish-brown, then another two narrow lighter bands and soon. In others, these narrow light bands may partially or completely coalesce to form a seriesof broad pale bands, or in some a mixture of thin and broad bands. Generally, the bands tendto be most intense on the lower flanks. Occasional specimens may have scattered whitish orcreamish lateral or ventrolateral scales between the dark crossbands. The ventral colour isgreyish-brown, with only scattered splotches of creamish-white on the venter, but with the(hidden) anterior edge of each ventral pale creamish; the throat has a speckled appearance,with the scales whitish anteriorly and brownish posteriorly. Some significant features of thisspecies' morphology are: head shields large and partly symmetrical, but with parietals,prefrontals and frontal partly fragmented, but each shield nevertheless larger than napescales; nasals in contact; prefrontals present, but usually fragmented, with pairs between thefrontal and the nasals; preocular scale present, loreal absent; not in contact with nasal;postoculars 2; supralabials 7-8; posterior chin shields small and separated by smaller scales;body scales smooth and strongly imbricate in 19-21 rows at mid-body mid-body (males andfemales do not appear to have significantly different mid-body scale counts), with the hindedge of each scale pointed or bifid, and with a short median keel; ventral scales about threetimes as wide as the rest of the body scales; ventrals deeply notched, and ragged-edged onthe posterior margins and numbering around 135-155 (females do not appear to have ahigher ventral count than that of males); anal divided; subcaudals entire, 20-29 (males havesignificantly more subcaudals than females). Attains a maximum total length of only around55 cm., and a snout-vent length of about 47 cm.Distribution: Apparently restricted to large continental shelf reefs, (Ashmore Reef, HiberniaReef and Scott Reef), off the coast of north-west Western Australia.Habitat: Mainly inhabits the edges continental shelf reefs or reef flats in relatively shallowwaters less than 10 metres in depth. It is usually found in association with dense coral growth.Biology/Ecology: Essentially a diurnal species, it feeds on a variety of small fishes which itactively hunts during the day. Specimens are occasionally found with a growth of algae overthe skin, and no doubt this assists in camouflaging the animal as it forages amongst the coral.Ovoviviparous, producing up to 4 large living young in a brood.Toxicity: This is a small inoffensive species that rarely attempts to bite, but caution shouldnevertheless be exerted, because its venom is likely toxic to humans. No known fatalities14