AUSTRALIAN BIODIVERSITY RECORD - Calodema

Australian Biodiversity Record, 2007 (8): 1-124Hydrophis godeffroyi Peters, W. (1872): Mber. K. Preuss. Akad. Wiss. Berl. 1872: 848-861 [p.856, pl. 1 fig. 3]. Type data: syntypes ZMB 7593 2 specimens, ZMB 28399 2 specimens. Typelocality: Gilbert Ils (as Kings-Mills Ils) [Kiribati].Distira andamanica Annandale, N. (1905): Bull. Mus. R. Hist. Nat. Belg. (ns)1: 173-176 [p.174]. Type data: holotype IM 15238 Type locality: Andaman Ils, India.Distira mjobergi Lönnberg, E. and Andersson, L.G. (1913). K. Sven. Vetensk.-Akad. Handl.52(3): 1-173 [p. 13]. Type data: holotype NHRM 2402. Type locality: Cape Jaubert, WA.Hydrophis lamberti Smith, M.A. (1917): J. Nat. Hist. Soc. Siam 2: 340-342 [p. 340]. Type data:holotype BMNH 1946.1.9.20. Type locality: mouth of the Mekong (as Meklong) River, Gulf ofSiam, Vietnam.Description: This species has a robust body-form along most of its length, being fairly uniformboth anteriorly and posteriorly (and only moderately compressed posteriorly). The head isrelatively large, deep and not distinct from the neck, the width of head between the eyesbeing at least half the distance from tip of snout to rear edge of parietals. The base bodycolour in mature specimens is usually bluish-grey or greyish on the dorsum and whitish-creamon the lower lateral area and venter. Pattern is usually confined to a series of 30-60 broadblackish bars or transverse blotches over the dorsum, below which there may be a series ofsmall dark blotches and dark-edged ocelli. The 'bands' may be absent or at best very obscurein aged individuals, with the upper body usually being uniform bluish-grey. Some significantfeatures of this species' morphology are: head shields large and symmetrical; 10-14 solidmaxillary teeth following fang; dentary teeth usually fewer than 23; heart just behind anteriorthird of body; supralabials 6-8; 3rd and 4th supralabials contacting orbit; nasal separated frompreocular by high 2nd supralabial; 1 preocular; 2-3 (usually 2) postoculars; 1-2 primarytemporals (occasionally 1 large secondary temporal); mental groove present and distinct;mental triangular, broader than long, and not partially hidden in the shallow mental groove;anterior chin shields large and usually bordering the mental groove; body scales smooth andimbricate, but juxtaposed dorsally with a short keel, and in 42-62 rows at mid-body (Australianspecimens tend to have higher mid-body scale counts than those from Asia - 45-62 vs 42-54);body scales 34-41 rows at neck (Australian specimens tend to have slightly higher neck scalecounts than those from Asia - 34-41 vs 31-44); ventrals small, with two short keels, eachventral about twice as wide as adjacent body scales and never foliform; ventrals 235-338,with those on the posterior body being entire (Australian specimens tend to have higherventral counts than those from Asia - 278-338 vs 235-294). Variation in morphology suggeststhat this species may be composite. Attains a mature snout-vent length of only around 85 cm.up to maximum of about 1m., however, on occasions specimens are found measuring around1.6 m. in total length. Males attain a larger size than females, and females are sexuallymature at around 80cm.Distribution: Widely distributed across South East Asia, from the Persian Gulf to India, SriLanka, Myanmar, Thailand, Malaysia, Vietnam, China, Japan, Philippines and Indonesia andacross to Australasia (including New Guinea) and the south west Pacific (Kiribati). In ourregion, it is known mainly from tropical and sub-tropical seas, being found off the coasts ofQueensland, Northern Territory and Western Australia to about Exmouth (but also as farsouth as Geographe Bay, WA as vagrants), and on occasions off New South Wales, Victoriaand even Tasmania as well (as vagrants). However, the Australian population is unique andendemic to this region, and I consider that it should be separately recognized as a differentspecies - see the use of Chitulia ocellata (Gray, 1849) in the taxonomic footnote below.Habitat: Known to live around coral reefs, as well as the turbid waters of river deltas, bays,estuaries and gulfs on continental shelf areas in depths ranging from around 4m. to around22m, although it is known from relatively deeper waters - sometimes exceeding 30 metres.Biology/Ecology: Essentially a diurnal species, its diet consists of a variety of small fishes.Gravid females have been found in Asia during the Dry Season (March-April), and it ispresumed that the young are born before around the early Wet or Summer Monsoon Season.29