Acta Parasitologica, Vol. 51, No. 2, 2006, 123-129 Reda M. El-S. Hassanine - Acanthocephalans from Red Sea fishes. Family Cavisomidae
Meyer, 1932: The seasonal cycle of Diplosentis nudus
(Harada, 1938) Pichelin et Cribb, 2001 in a definitive fish host,
and a comment on Sclerocollum Schmidt et Paperna, 1978
Department of Sciences and Mathematics, New Valley-Faculty of Education, Assiut University, El-Kharga, New Valley, Egypt
*Corresponding address: Redaaa2003@yahoo.com
ABSTRACT
Specimens of the fishes Rastrelliger kanagurta (Scombridae) and Siganus luridus (Siganidae) were caught in the Red Sea off
the coast of Sharm El-Sheikh, South Sinai, Egypt. R. kanagurta was parasitised by Diplosentis nudus (Harada, 1938) Pichelin
et Cribb, 2001 (Acanthocephala, Cavisomidae), and S. luridus by Sclerocollum rubrimaris Schmidt et Paperna, 1978
(Acanthocephala, Cavisomidae). The infection of R. kanagurta was followed monthly for one year (from September, 2004 to
August, 2005). As a result, the seasonal cycle of D. nudus in its definitive host is described herein for the first time. The cycle
is well-defined and extends for about 11 months (from October to August); in October, new generation of D. nudus starts to
appear in the intestine of R. kanagurta; during the winter, the juvenile worms continued their growth; during the spring, most
of the worms attained maturity and the mature worms copulated; during the summer, the worms began to die off naturally prior
to their elimination from the intestine of the host. Sclerocollum rubrimaris is redescribed and Sclerocollum Schmidt et Paperna,
1978 is retained as a valid genus within the Cavisomidae.
KEY WORDS: Acanthocephala, Cavisomidae, Diplosentis nudus, Sclerocollum rubrimaris, seasonal cycle, Red Sea fishes