Transversotrema

Hunter, Janet A., Hall, Kathryn A. & Cribb, Thomas H., 2012, A complex of Transversotrematidae (Platyhelminthes: Digenea) associated with mullid fishes of the Indo-West Pacific Region, including the descriptions of four new species of Transversotrema, Zootaxa 3266, pp. 1-22 : 13-14

Transversotrema sp. E

( Fig. 5 )

Hosts: Mullidae : Mulloidichthys vanicolensis (Valenciennes) , yellowfin goatfish, Mulloidichthys flavolineatus (Lacepède) , yellowstripe goatfish; Parupeneus ciliatus (Lacepède) , whitesaddle goatfish

Site: beneath scales.

Locality: off Lizard Island, northern Great Barrier Reef, Queensland, Australia (14°40´S 145°28´E).

Prevalence: (see Table 3)

Intensity: data not recorded.

Deposition of specimens: voucher QM G231686 (ex M. vanicolensis , Lizard Island, coll. T. H. Cribb et al., May 2008).

Description: Based on one mature specimen. Body transversely elongated, dorsoventrally flattened, widest at equator. Tegument spined. Eyespots central, medial; no pigment other than eyespots evident. Ventral sucker well posterior to eyespots, in posterior half of body. Pharynx prominent, between eyespots. Oesophagus short. Intestine present as cyclocoel, bifurcation immediately anterodorsal to ventral sucker. Testes paired, loosely round, very deeply lobed, symmetrical not contiguous. Seminal vesicle extremely long, distinctly bipartite, composed of enclosed (by cyclocoel) and extracaecal portions; enclosed portion proximal to testes, saccular, distinctly lobed, anterodextral to right testis, constricted distally to form narrow duct which passes ventral to cyclocoel and leads to extracaecal portion; extracaecal portion tubular, winding, long, passes laterally along line of cyclocoel towards midline of body, then turns anteriorly and proceeds dextral to pharynx and between eyespots while completing one helical turn, then proceeds laterodextrally and expands, before turning sinistroanteriorly at point of expansion and forms naked ejaculatory duct which proceeds to genital pore. Genital pore median. Ovary deeply lobed, sinistral to, but not contiguous with, left testis; oviduct passes medio-posteriorly from ovary, arises from anterior-most lobe of ovary. Uterine seminal receptacle, lies between ovary and left testis. Laurer’s canal not observed. Uterus passes medially between anterior reach of cyclocoel and testes, proceeds between right testis and saccular portion of seminal vesicle, then proceeds ventral to cyclocoel, and anterosinistrally to join ejaculatory duct at common genital pore. Vitellarium follicular; vitelline follicles dense, scattered in extracaecal and enclosed areas of body; extracaecal follicles fill posterior region of body, extend laterally into anterior portion of body, present in median portion of anterior part of body, but scant and form one loose row; enclosed follicles in 2 masses few follicles scattered in interrupted band along inner posterior margin of cyclocoel. Vitelline duct prominently arises from each enclosed vitelline mass, runs anterior to testes and ventral to cyclocoel. Eggs (7) tanned, unembryonated in utero.

Molecular data: Sequences were obtained from the 28S region from three specimens: P. ciliatus (1) and Mulloidichthys vanicolensis (2); from the ITS1 region from three specimen – P. ciliatus (1) and Mulloidichthys flavolineatus (2); and from the ITS2 region from five specimens – P. ciliatus (2), Mulloidichthys flavolineatus (1), and Mulloidichthys vanicolensis (2). ( Table 2 .).

Remarks: We have only one morphological specimen for Transversotrema sp E, however the specimen is distorted and measurements were not taken. A potential morphological difference distinguishing it from other species in this complex is in the size of the vitelline follicles which are large and scattered seemingly randomly across the anterior margin. This may be one character to distinguish this species from T. tragorum n. sp. and T. cutmorei n. sp. which have few follicles in the anterior margin. Molecular data (below) are strongly convincing that this digenean from two species of Mulloidichthys and at least one species of Parupeneus is distinct from other transversotrematids from mullids ( T. cabrarum n. sp., T. cutmorei n. sp., T. chevrarum n. sp., T. tragorum n. sp.) and all other Transversotrema species characterised by Hunter et al. (2010) and Hunter & Cribb (2012). The molecular data is convincing, however, until good morphological samples become available it will not be possible to name this species.

Figures

FIGURE 5. Transversotrema sp. E ex Mulloidichthys vanicolensis Lizard Island GBR. Scale = 500 µm.