Biology of Crassicutis cichlasomae, a parasite of cichlid fishes in Mexico and Central America

Abstract

Field study on the biology of Crassicutis cichlasomae Manter, 1936 (Digenea: Homalometridae) was carried out in a small swamp in a limestone factory near Mérida, Yucatán, Mexico. Aquatic snails, Littorina (Littoridinopsis) angulifera, harbouring C. cichlasomae rediae, cercariae and metacercariae, served both as the first and second intermediate hosts. Feeding experiments confirmed the conspecificity of metacercariae from naturally infected snails with adults from naturally infected fish. Gravid C. cichlasomae worms were obtained from experimentally infected fish 19 days post exposure at 22–24°C. Examination of fish from the swamp in Mitza and other localities in the Yucatan Peninsula showed that the cichlids Cichlasoma urophthalmus and C. meeki were definitive hosts of C. cichlasomae. There was no pronounced preference of C. cichlasomae adults for the site of their location in the intestine of the definitive host; a slightly higher proportion (41%) of worms was only found in the anterior third of the gut. The time of miracidium development varied from 18.5 to 27.5 days; different temperature (20.1–35.7°C) or light/darkness regimes influenced only slightly the rate of embryonic development, with shorter development times at higher temperature (34.8–35.7°C) and constant darkness and/or light. With the exception of the sporocyst, all developmental stages are described and figured.

Larval trematodes infecting the South-American intertidal mud snail Heleobia australis (Rissooidea: Cochliopidae)

“…Three apocreadiid cercariae have been described from Heleobia spp. : Homalometron pseudopallidum Martorelli, 1986, a parasite of H. castellanosae (Martorelli 1986a The life cycles of the apocreadiids include cercariae with eyespots and setae that parasitize prosobranchs, as the form described here; these cercariae encyst in invertebrates such as snails, bivalves, and annelids (Stunkard 1964a, Martorelli 1986a, Scholz et al 1995. The adults have been found in both marine and freshwater fish and also chameleons (Olson et al 2003).…”

On some trematodes parasites of fishes from Paraná River

“…In South America the genus Crassicutis Manter, 1936 is represented by C. chuscoi (Pearse, 1920) and C. wallini (Pearse, 1920) in Venezuela, and by C. intermedius (Szidat, 1954) in Argentina (Szidat, 1954), Brazil (Kohn & Fróes, 1986) and Paraguay (Bray et al, 1996). Crassicutis cichlasomae was described by Manter (1936) from the stomach of Cichlasoma mayorum from Mexico; Scholz et al (1995a) described the life cycle and, referred other hosts in Mexico and Central America. In this opportunity we report C. cichlasomae for the first time in South America and in a new host: Geophagus brasiliensis.…”

The structuring process of the macroparasite community of an experimental population of Cichlasoma urophthalmus through time

“…These three species have active transmission, which means that the larval stages of the parasite actively seeks its hosts and either penetrates it (O. manteri and E. leopoldinae) or attaches to the gills (S. mexicanum) (Aguirre-Macedo, 1990;Scholz et ah, 1994;Mendoza-Franco et al, 1995). In contrast, C. cichlasomae uses a benthic mollusc (Pi/rgophorus coronatus) as both first and second intermediate host; this means that cercariae are in the mollusc and the metacercariae never emerge (Scholz et al, 1995). Thus, wild fish feeding on molluscs around the shores of the waterbody would acquire the infection passively; caged fish, however, could not acquire C. cichlasomae because they were not in contact with benthic molluscs.…”