Bioacoustics of Lernanthropus mollis

Remarks: The only other Lernanthropus species reported from a sillaginid host is L. sillaginis Pillai, 1963 which was described from females collected from the gills of Sillago sihama caught off Trivandrum, India ( Pillai, 1963 ). The male of L. sillaginis was described subsequently by Song & Chen (1976) based on Chinese material from the same host. There is also material of L. sillaginis in the NHM, London collections, from S. sihama caught off the Iraq coast in the Arabian Gulf (NHMUK 2013.52–53). Lernanthropus sillaginis was reported from Sillago maculata caught off Thailand ( Sirikanchana, 1982 ) and by Hayward (1997) from S. aeolus , S. arabica McKay & McCarthy, 1989 , S. attenuata McKay, 1985 , S. chondropus Bleeker, 1849 , S. parvisquamis Gill, 1861 and S. sihama over a range extrending from the Arabian Gulf in the west through to China in the east and Bali ( Indonesia ) in the south. Subsequently, Raja et al . (2018) reported it from S. vincenti McKay, 1980 in Indian waters. The only record from a non-sillaginid host is that of Ho & Kim (2004) , who found L. sillaginis on Priacanthus tayenus Richardson, 1846 caught off Thailand . The females of these two species are readily distinguishable: L. sillaginis has a large trunk with a broad dorsal trunk plate that flares out posteriorly so that it is twice as wide as the cephalothorax, whereas the trunk of L. mollis is slender and the small dorsal trunk plate is only about 1.2 times wider than the cephalothorax. In addition, the bilobed, foliaceous third legs are separated in the midline in L. sillaginis , but are unilobate and fused in the midline in L. mollis . The male of L. mollis is described here for the first time. It is very similar to the male of L. sillaginis , but can be distinguished by its better defined abdomen, slightly longer caudal rami, and longer exopodal lobe of leg 3 (relative to leg 4).