title: Larval Pseudoproleptus sp. (Nematoda: Cystidicolidae) found in the Amazon river prawn Macrobrachium amazonicum (Decapoda: Palaemonidae) in Brazil.
abstract: Previously undescribed infective larvae of the cystidicolid nematode Pseudoproleptus sp. (probably conspecific with the nematode originally described as Heliconema izecksohni Fabio, 1982, a parasite of freshwater fish in Brazil), were found encapsulated in the hemocel of the Amazon river prawn Macrobrachium amazonicum (Heller) (Decapoda: Palaemonidae) from the natural canals on the Mexiana Island (Amazon River Delta), Pardá State, Brazil. The prevalence in prawns (body length 48-110 mm) examined in January and March 2008 (n = 44) was 32%, with an intensity of 1-6 (mean 2) larvae per crustacean. The nematode larvae (body length 19.7-25.7 mm), characterized by the cephalic end provided with a helmet-like cuticular structure having a thickened free posterior margin, are described based on light and scanning electron microscopy. Apparently prawns play a role as intermediate hosts for this nematode species. This is the first record of a larval representative of Cystidicolidae in South America and the first record of a species of Pseudoproleptus Khera, 1955, in the Neotropics. Heliconema izecksohni is transferred to Pseudoproleptus as Pseudoproleptus izecksohni (Fabio, 1982) n. comb.
authors.affiliation: Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, Branisovská 31, 37005 Ceské Budĕjovice, Czech Republic. moravec@paru.cas.cz
authors.forename: Frantisek
authors.initials: F
authors.lastname: Moravec
authors.forename: Cláudia P
authors.initials: CP
authors.lastname: Santos
mesh_terms: D000818:Animals; D001938:Brazil; D007814:Larva / Q000033:anatomy & histology / Q000145:classification / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D033541:Palaemonidae / Q000469:parasitology*; D045483:Rivers; D013151:Spiruroidea / Q000033:anatomy & histology / Q000145:classification / Q000302:isolation & purification*