New host record for Livoneca redmanni (Leach, 1818) (Isopoda: Cymothoidae) in the Brazilian coastal waters with aspects of host-parasite interaction

Abstract

and Sathyabama Chellappa Universidade Federal do Rio Grande do Norte Centro de Biociencia - Programa de Pos-Graduacao em Bioecologia Aquatica (Praia de Mae Luiza, s/n, 59014-100 Natal, RN, Brasil) **Corresponding authors: eudriano@yahoo.com.br; chellappa.sathyabama63@gmail.com Cymothoids are among the largest parasites of fishes. These are the isopods commonly seen in numerous families and species of fishes of commercial importance, in tropical and subtropical waters, attached on the body surface, in the mouth or on the gills of their hosts (BRUSCA, 1981; BUNKLEY-WILLIAMS; WILLIAMS, 1998; LESTER; ROUBAL, 2005). Some cymothoids form pouches in the lateral musculature of few freshwater and marine fishes; are highly host and site specific (BRUSCA, 1981; BUNKLEY-WILLIAMS; WILLIAMS, 1998). They are protandrous hermaphrodites which are unable to leave their hosts after becoming females. All gravid females posses a marsupium or brood pouch on the ventral surface of the body, within which the young are held until they become manca, and there is no larval stage (BULLAR, 1876; BUNKLEY- WILLIAMS; WILLIAMS , 1985, 1998. WILLIAMS; WILLIAMS, 1998,). The mancae have only six pairs of legs (compared to seven in juveniles and adults), large compound eyes and pleopods with setae with which they swim very rapidly. After a short free-swimming period they need to find a host fish to take the first meal within one to two days or they die (LESTER, 2005). Like most isopods, cymothoids are considered to feed principally on host blood, but they may consume the mucus, epithelium and subcutaneous tissues of their hosts (LANZING; O’CONNOR, 1975; GRABDA, 1991; LESTER; ROUBAL, 1995; BUNKLEY-WILLIAMS; WILLIAMS, 1998, RAMDANE et. al., 2007). The species Livoneca redmanni (Leach, 1818) has been found only on cero, Scomberomorus regalis and serra Spanish mackerel, S. brasiliensis (Osteichthyes: Scombridae), in pairs in the gill-chamber. L. redmanni causes extreme damages to these fishes and can kill them, causing significant loss of these valuable fishes. L. redmanni occurs in the Caribean and the South American coasts to Rio de Janeiro, Brazil (WILLIAMS; BUNKLEY-WILLIAMS, 1996). __________