Lernaeenicus Le Sueur, 1824

Aneesh, Panakkool Thamban, Helna, Ameri Kottarathil, Kumar, Appukuttan Biju & Maran, Balu Alagar Venmathi, 2018, Redescription of Lernaeenicus stromatei Gnanamuthu, 1953 (Copepoda: Siphonostomatoida: Pennellidae) infesting the Black Pomfret Parastromateus niger (Bloch) from Indian waters, Zootaxa 4482 (2), pp. 375-382 : 376-377

Genus Lernaeenicus Le Sueur, 1824

Lernaeenicus Le Sueur, 1824 – Wilson, 1932, p. 480; Yamaguti, 1963, p. 185; Pillai, 1985, p. 716, Aneesh, 2014, p. 168.

Syn. Foroculum Thompson W, 1844

Lernaeonema H Milne-Edwards, 1840

Lerneoceropsis Fowler, 1912 .

Type species: Lernaeenicus radiatus Le Sueur, 1824

Generic diagnosis: The genus Lernaeenicus Le Sueur, 1824 , has been distinguished from other pennellids by the following characteristic features, (1) cephalon with two or more simple, nodular or branched cephalic processes projecting outwards or obliquely backwards, (2) antennule 2–5 segmented, Antenna three segmented and chelate, proboscis with three chitinous rings, (3) neck, narrow and usually bent, with four pairs of small swimming legs; first two pairs of legs placed close together, biramous, 3–4, uniramous, 4) enlarged, straight and cylindrical trunk and a narrow abdomen, 5) caudal rami present or absent and the egg strings long and slender with strongly flattened eggs.

Neotype designation for Lernaeenicus stromatei Gnanamuthu, 1953 : The original description of Lernaeenicus stromatei was accompanied by six figures of the adult female and six figures of metamorphosed larvae. Even though the original description contains some species-specific details, it need s to be updated according to the modern taxonomic standard. Fortunately, the type locality (Madras, Tamil Nadu, India), and the type hosts of L. stromatei were clearly mentioned, namely Stromateus niger (= Parastromateus niger ). Gnanamuthu (1953) mentioned that the holotype was deposited in Indian museum, Kolkata and the paratypes were in the author’s personal collection, but the author did not include registration number s. Later, Pillai (1985) clearly stated that all materials, including the type, are lost, and this statement is supported by our present museum search. Enquiries at the Indian museum, failed to reveal any material that could be identified as the type material for L. stromatei .

There are few subsequent record s of the species. Pillai (1985) provided a description based on the original description but didn’t provide drawings and stated that the species closely resembled L. hemiramphid . According to Gnanamuthu, the head of L. stromatei is asymmetrical, but figures in the original description do not show this asymmetry. Pillai (1985) also doubted the presence of incomplete divisions on the neck. If true, it would be a useful distinguishing character of this species.

The new material of Lernaeenicus stromatei Gnanamuthu, 1953 described here was recovered from the type host Parastromateus niger . The present materials were collected from three different localities in India (Chennai Coast, Bay of Bengal; Ayyikkara fish landing Centre, Malabar Coast; Behala fish market, West Bengal) and Madras (=Chennai) the type locality.

Remarks. The present material is slightly larger (70 mm) than the size range of adult females (14–63 mm) of L. stromatei given by Gnanamuthu (1953) and the host was also smaller in size. However, the present neotype is from a large- sized host fish ( P. niger = 41.5 cm). The correlation between sizes of the host and parasite has been previously reported ( Helna et al. 2016). We confirm that both are the same species of Lernaeenicus and we designate a neotype in order to conserve Gnanamuthu’s (1953) authority and description of this species.