Some New Zealand Parasitic Copepoda of the Family Anthosomidae
L. microlamini seems to be most closely related to a group of species or subspecies recorded from many parts of the world on Caranx spp. Initially these were described as L. giganteus by Krøyer (1863, p.280, pl. 8, fig. 1) from Brazil, then Wilson recorded specimens from the West Indies (1913, p.227, pl. 33, fig. 148-150, pl. 35) under the same name, although Wilson's figures differ from those by Krøyer in the length of the plate of the thoracic segment (40% of total length in Krøyer's figure, 30% in Wilson's), as well as in the shape of this plate; Kirtisinghe (1956, p. 18, fig. 11) recorded specimens from Colombo under the name L. trifoliatus Bassett-Smith but later (1964, p.98, figs. 132-137) gave further records from the Gulf of Mannar area, now placing these and his previous records as L. giganteus; meanwhile Pillai (1964, p.48, fig. 9) recorded specimens from the same host genus from nearby Trivandrum as L. carangis Pillai (nec. L. carangis Hesse, 1878 which page 12was removed from the genus Lernanthropus by Wilson, 1922, p.46); these Indian Ocean specimens differ from those of Wilson and Krøyer in having a broadly laminate fifth pereiopod while the latter show their specimens as having filiform fifth pereiopods.
The present material can readily be distinguished by the third pereiopods which extend little beyond the plate of the fourth thoracic segment, while in the above records these appendages project beyond the plate for one-third its length, and also by the lack of fifth pereiopods which are well developed in the above records.
The present species is also very similar to L. trifoliatus Bassett-Smith (1898, p.12, pl. 7, fig. 1) but differs in having the plate of the fourth thoracic segment narrowed posteriorly while in L. trifoliatus it becomes wider and then broadly rounded posteriorly, and again in the lack of the fifth pereiopods which are particularly well developed in L. trifoliatus.
It seems possible that the present species and L. trifoliatus are closely related to the specimens recorded from Caranx spp. but, until such time as larger collections from a variety of geographical localities makes revision of this group possible, there is no way of deciding the extent of this relationship.