AUSTRALIAN BIODIVERSITY RECORD - Calodema

Australian Biodiversity Record, 2007 (8): 1-124adjacent body scales); anal divided; nasal contacts the single preocular; parietals and frontalfragmented; no prefrontal scales. There are 5-8 solid maxillary teeth behind the fang. Attainsa maximum total length of around 1.2 m., and a snout-vent length of about 1 m.Distribution: Although this species is virtually endemic to the Australian region, includingsouthern New Guinea, it also occurs in Indonesia and the south-west Pacific to about NewCaledonia. Within Australian territory, it is largely confined to tropical seas off the coasts ofQueensland, Northern Territory and the north-west of Western Australia (to about as far southas Barrow Island). Occasionally specimens may be found along the subtropical far north eastcoast of New South Wales as well, but no permanent population occurs in this State (notealso that this species was not mentioned as part of the NSW fauna in the most recent guide tothat region (Swan, Shea and Sadlier, 2004).Habitat: It mainly inhabits sand beds of coral reefs in relatively shallow (about 4 to 20 metresdeep) continental shelf waters. It appears to be more common around the outer edges ofreefs.Biology/Ecology: This is essentially a nektonic, nocturnal predator of several species of smallfishes, particularly Gobies, which it either actively hunts around coral, or by searching burrowsand crevices. It can also be observed active in shallow reef waters during daylight as well -and at any time of the year. It is ovoviviparous, producing up to 10 living young in a brood,although the average is only around 4, with larger females tending to have larger litters. In theTorres Strait, a gravid female has been recorded in November (Summer/early Wet Season),while one in Asia (South China Sea) was gravid in April - weather conditions (early MonsoonSeason). On occasions specimens of this species are accidentally captured during fishingoperations in northern Australia.Toxicity: In general this species is not overtly aggressive when disturbed, and indeed willusually refrain from biting unless provoked by very rough treatment or handling duringcapture. Caution should nevertheless be exerted, because its venom is known to be highlytoxic. Although there are no recorded human fatalities from this species, urgent medicalattention should always be sought in the event of a bite.Survival Status: Protected under the Qld Nature Conservation Act (1992), the Territory Parksand Wildlife Conservation Act (1998) and the WA Wildlife Conservation Act 1950 (asamended). Protected under the New South Wales National Parks and Wildlife Act (1974) butnot listed in that State as a Threatened Species in any of the Schedules of the NSWThreatened Species Conservation Act (1995). Listed as a Marine Protected Species underthe Australian Environmental Protection and Biodiversity Conservation Act (1999). It isprobably not under threat, but its restricted distribution in Australian waters could potentiallymake it vulnerable in some parts of its range.Etymology: The name ‘peronii’ honours the French naturalist Francois Peron (1775-1810).Genus Astrotia Fischer, 1856Astrotia Fischer, J.G. (1856): Abh. Geb. Naturw. Hamburg 3: 1-78 [p. 38]. Type species:Hydrophis schizopholis Schmidt, 1846 by monotypy.Diagnosis: As presently defined a monotypic genus of extremely large marine snakes of thefamily Hydrophiidae, readily separated from all other genera by the following combination ofcharacters: Head long, deep, and squarish (or weakly rounded) in shape when viewed fromabove, (but with the snout slightly or steeply angular in profile), and barely distinct from neckor not at all; head shields large and symmetrical, with each shield much larger than adjacentnape scales; valvular nostrils and lingual fossa; nasals in contact; prefrontals present; 1preocular; 2 postoculars; 2 primary temporals; supralabials 10-11 (occasionally divided);mental shield triangular in shape, wider than long; distinct but shallow mental groove; mentalshield not partially hidden in the mental groove; body scales relatively smooth, stronglyimbricate, each with either a central week keel or small line of tubercles, and in 46-63 rows atmid-body; ventrals longitudinally divided (i.e. divided into pairs of foliform scales), strongly23