Sexual status of Paralabrax humeralis (Serranidae) and infection by Philometra sp. (Nematoda: Dracunculoidea)

Abstract

Evidence is presented that Philometra sp. infects Paralabrax humeralis only after first maturity

Philometra chilensis (Nematoda, Philometridae) affects the fecundity of the red cusk-eel, Genypterus chilensis (Guichenot) (Pisces, Ophidiidae) in Chile

“…The negative impact of gonadinfecting philometrid nematodes on the reproductive success of their hosts has been suggested by Moravec and SalgadoMaldonado (2007), Moravec et al ( , 2008 and Perez et al (2009), among others. Oliva et al (1992) found no evidence of histological damage in the gonads of Paralabrax humeralis infected by Philometra sp., although a moderate leukocytic infiltration was detected.…”

“…A close relationship between reproduction of the host and parasitic infection has been suggested by Oliva et al (1992). They indicated that fish that had grown larger than their size at first maturity are likely to be infected, but immature fish and hermaphrodites are not susceptible to infection.…”

“…Only two examples of Philometra sp. infections of the gonads of Chilean marine fish have been reported: In the Peruvian sea bass, Paralabrax humeralis (Valenciennes) (Serranidae), a close association was found between fish size at first maturity and infection, where only fish larger than those at the first maturity (males and females) were found to be infected (Oliva et al 1992). In the fine flounder, Paralichthys adspersus (Steindachner) (Paralichthyidae), both males and females were infected; a relationship between host size and prevalence and mean intensity of infection was not evident, but the values of prevalence and mean intensity were higher in females than in males (Oliva et al 1996).…”

Pathological effects of Eustrongylides sp. larvae (Dioctophymatidae) infection in freshwater fish, Glossogobius giuris (Ham.) with special reference to ovaries

“…The present observations are consistent with the work of Heins and Baker (2003) who found that mean egg size in three spined stickleback (Gasterosteus aculeatus) was smaller in fish infected by the cestode, Schistocephalus solidus than in non-infected fish. Oliva et al (1992) further suggested that philometrid infection resulted in reduced fecundity in Chilean sea bass (Paralabrax humeralis) because the effective volume of the ovaries was reduced. Necrosis was described in the ovaries of striped mullet (Mugil cephalus) due to infection by Philometra cephalus (Ramachandran 1975).…”

“…Although, many workers viz. Ramachandran (1975), Oliva et al (1992), Moravec et al (1997Moravec et al ( , 2002, Hesp et al (2002), Clarke et al (2006) and Perez et al (2009) was explored the effect of Dracunculoid nematode on the ovaries and reproductive potential in number of fish hosts. But a very little work has been done on the effect of Eustrongylides sp.…”