A New Species of Transversotrema (Trematoda: Digenea) from Marine Fishes of Australia

Abstract

Transversotrema licinum sp. n. (Trematoda:Digenea: Transversotrematidae) is described from Scorpius sp. and Microcanthus strigatus in Queensland, Australia. It is ectoparasitic beneath the scales of the host. The genus Transversotrema Witenberg, 1944 (Family Transversotrematidae) is remarkable in its laterally extended body, lack of oral sucker, weakly muscular acetabulum, and other characters. The type species, T. haasi Witenberg, 1944, was found in a basin containing about 20 species of fishes from the Red Sea; its precise host and location in the host are still unknown. The peculiar Cercaria patialensis Soparkar, 1924, protandrous in a freshwater snail, Melanoides tuberculata (Miiller, 1774) in India, is a species of Transversotrema, T. patialense (Soparkar, 1924) Yamaguti, 1958. It has been reported from the same or related species of snail in the Congo (Brien, 1954) and in Ceylon. The structure and life cycle of T. patialense were further described by Crusz, Ratnayake, and Sathananthan (1964) who found metacercariae in abundance under the scales of Macropodus cupanus (Cuv. and Val.) (Osphronemidae), Ophiocephalus punctatus Bloch (Ophiocephalidae), and Tilapia mossambia (Peters) (Cichlidae), all freshwater fishes of Ceylon. These fishes were experimentally infected by cercariae from M. tuberculata. Olivier (1947) described Cercaria koliensis from Melanoides terebra (?) (Lesson) in the Solomon Islands. He noted its similarity to Transversotrema but did not place it in that genus. Yamaguti (1958) states it belongs there, so the correct name is Transversotrema koliensis (Olivier, 1947) Yamaguti, 1958. There seems no doubt that Yamaguti used the word apparently in the sense of obviously. Velasquez (1958) named Transversotrema Received for publication 30 December 1969. * Studies from the Department of Zoology, University of Nebraska, Lincoln, Nebraska, No. 415. Supported in part by NSF Grant GB 468. laruei from Lates calcarifer Bloch in the Philippines. At that time, the few specimens found were thought to come from the muscles and intestine. Later studies (Velasquez, 1961) showed that the bioculate, furcocercous, protandrous cercariae of this species emerged from rediae in brackish water snails, Thiara riquettii Grateloup, and became metacercariae under the scales of several species of freshwater and brackish water fishes. The species described below is the one mentioned in an abstract by Manter (1965). It occurred sexually mature beneath the scales of two species of marine fishes in Moreton Bay, Queensland, Australia. Eggs were usually present in the uterus and there seems no reason why the worms should not be considered normal adults, rather than progenetic