E. Moravec et Dg. Huffman, Observations on the biology of Rhabdochona kidderi texensis, a parasite ofNorth American cichlids, J HELMINTH, 75(2), 2001, pp. 197-203
An examination of a sample of benthic invertebrates collected from the Uppe
r San Marcos River in southwestern Texas, USA in September 1999 revealed th
at the nymph of the ephemeropteran Tricorythodes curvatus served as natural
intermediate host of the nematode Rhabdochona kidderi texensis (Nematoda:
Rhabdochonidae), an intestinal parasite mainly of the Rio Grande perch (Cic
hlasoma cyanoguttatum) in this locality; the prevalence of the parasite's t
hird- and fourth-stage larvae in mayflies was 6.8% with the intensity of 1-
2 larvae per nymph. Live R. kidderi texensis eggs collected from nematodes
recovered from C. cyanoguttatum in Texas were transported to the Czech Repu
blic, where they were used to experimentally infect nymphs of the palaearct
ic mayfly species Paraleptophlebia submarginata; the development of infecti
ve third- and fourth-stage larvae in this experimental intermediate host wa
s completed after approximately 10 days at 19 degreesC. Infected nymphs wer
e fed to aquarium-reared fishes, four Cichlasoma Nigrofasciatum and one Ore
ochromis niloticus, of which only three of the former became infected. The
last (fourth) moult of a male nematode was observed in C. nigrofasciatum 23
days p.i. and adult males and gravid females with not fully mature (non-em
bryonated) eggs in uteri on days 40 and 51 p.i. The prepatent period of R.
kidderi texensis is approximately two months.