Nicholas, W. L. (2007). A new species of Trileptium (Nematoda, Thoracostomopsidae) from a sandy beach in southeastern Australia, with a key to species and observations on geographical distribution. New Zealand Journal of Marine and Freshwater Research. 41(3): 335-344.
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Nicholas, W. L.
2007
A new species of <i>Trileptium</i> (Nematoda, Thoracostomopsidae) from a sandy beach in southeastern Australia, with a key to species and observations on geographical distribution
New Zealand Journal of Marine and Freshwater Research
Thoracostomopsidae are common predatory marine nematodes found in
littoral and sub-littoral sands. The buccal cavity is characterised by
a mandibular complex and onchia (teeth) forming grasping jaws. Three
constituent subfamilies and genera are distinguished by variations in
the development of these structures. Of the three subfamilies,
Thoracostominae have been found in sub-littoral habitats and have not
been reported from Australia. A number of species from several genera
of Enoplolaiminae have previously been recorded from southeastern
Australian beaches. In this paper, Trileptium australis n. sp.
belonging to the third subfamily, Trileptiinae, is described from one
of these beaches. In this genus, weakly developed mandibles and one, or
three, well developed onchia are situated closer to the mouth opening
than in Enoplolaiminae, and the lips have a lower profile. Important
specific diagnostic characters of Trileptium australis n. sp. are the
possession of three onchia, absence of cuticular annulation, presence
of a precloacal supplementary organ, thin strongly curved spicules with
mid-ventral pegs and a gubernaculum that loops over the spicules. A
dichotomous key for the 11 described species, based on male characters,
is provided. The geographical distribution of all the described species
is reviewed. One species, T. subterraneum has a very wide geographical
distribution, but other species appear to be restricted to one sea or
ocean.