Experimental Infection of Two Species of Wrasse With The Digenean Proctoeces Subtenuis

Abstract

Uzmann (1959), and by Uzmann (1953). P. subtenuis has usually been recorded from the hind-gut oflabrid and sparid fishes in tropical and subtropical seas, and Freeman & Llewellyn suggested that the occurrence of adult forms of the parasite in an invertebrate host was probably abnormal, and that the more normal life cycle includes a vertebrate as the definitive host. In Britain P. subtenuis has never been recorded from a fish, and so it has not been possible to make a direct comparison of specimens from an invertebrate with specimens from a vertebrate. It was therefore decided to attempt to infect suitable British fishes with specimens of P. subtenuis obtained from S. plana, and to compare any surviving parasites from these fishes with others collected directly from the mollusc. MATERIALS AND METHODSThe fishes used in the experiments were the only two labrids available in sufficiently large numbers in the Plymouth area, the two wrasse species Ctenolabrus rupestris (L.) and Crenilabrus melops (L.). A total of 35 wrasse was used, the fishes being divided into two groups. Those of the first group of 18 (10 C. rupestris and 8 C. melops) were killed and their alimentary canals examined. Many of them were found to contain adult digeneans belonging to the family Allocreadiidae, as had been recorded previously by Nicoll (1910, 1914), and one of them had two unidentified metacercariae encysted in the peritoneal fat, but not one of them contained a single specimen of P. subtenuis. It was therefore assumed that the remaining 17 wrasse (7 C. rupestris and 10 C. melops) to be used in subsequent experiments were free from naturally occurring P. subtenuis. These 17 specimens of wrasse varied in length between 10 and 20 em. The sizes of the fishes in which P. subtenuis 8

Morphology and molecular analysis of life-cycle stages of Proctoeces maculatus (Looss, 1901) (Digenea: Fellodistomidae) in the Bizerte Lagoon, Tunisia

“…Identification of members of the genus Proctoeces Odhner, 1911 is quite difficult due to the scarcity of reliable taxonomic distinguishing characteristics, the lack of consistent diagnostic characteristics and the great morphological and morphometrical variability found even within specimens of the same population parasitizing different hosts (Freeman & Llewellyn, 1958; Freeman, 1963; Dollfus, 1965; Lang & Dennis, 1976; Wardle, 1980; Bray, 1983). For this reason, the taxonomic position of many species previously described has been questioned and many species have been synonymized with the type-species P. maculatus (see Bray & Gibson, 1980; Bray, 1983), a species of worldwide distribution which displays diverse life-cycle patterns in a broad variety of hosts (Bray, 1983).…”

Two known and one new species of Proctoeces from Australian teleosts: Variable host-specificity for closely related species identified through multi-locus molecular data

“…Proctoeces Odhner, 1911 is an enigmatic genus in the family Fellodistomidae Nicoll, 1909, comprising species reported from a wide range of marine animals. As sexually mature adults, species of the genus have been reported from many families of teleost fishes globally; however, the genus is strongly concentrated in two families, the Sparidae and Labridae [1][2][3]. Unusually for the Fellodistomidae, species of Proctoeces may also develop into sexually mature adults in the second [4][5][6][7] and even the first intermediate host [2,[8][9][10]; in some instances, the definitive host has been apparently completely excluded from the life-cycle [11] and several species have been described solely on the basis of infections from invertebrates [5,7,12,13].…”

Exological Aspects of Proctoeces ichiharai (Trematoda: Digenea) Parasitic in Batillus cornutus (Gastropoda)

“…3) indicates that the period between larval and mature stage must be short compared with that between mature and 'post-adult' stage. tal conditions (Freeman, 1962;Sakaguchi et al, 1970b) and is very likely the same in natural infections (Freeman, 1962 cava were fed at certain intervals. All top shells were…”