Transversotrema cutmorei, Hunter, Janet A., Hall, Kathryn A. & Cribb, Thomas H., 2012

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 : 10-11

Transversotrema cutmorei n. sp.

( Fig. 3 )

Syn: T. licinum Manter, 1970 in part of Cribb et al. (1992)

Type-host: Upeneus tragula Richardson , Mullidae , freckled goatfish.

Site: beneath scales.

Locality: Moreton Bay, Queensland, Australia (27°15´S 153°15´E).

Prevalence: see Table 3

Deposition of specimens: Holotype QM G231900 (ex U. tragula , Moreton Bay, coll. S. Cutmore, 2 Nov. 2010); QM G231886 (ex U. tragula , Moreton Bay, coll. T. H. Cribb et al., Apr. 1993).

Etymology: this species is named for our colleague, Scott Cutmore, who recovered specimens from a goatfish in Moreton Bay and sequenced their ITS2 rDNA.

Description: Based on seven mature specimens. Body transversely elongated, dorsoventrally flattened, widest at equator 390–668 (525) µm long, 929–1920 (1516) wide. Tegumental spines prominent. Eyespots prominent 116–186 (147) µm apart; no pigment other than eyespots evident. Ventral sucker well posterior to eyespots, surface area 4,451–6,347 (5,537) µm2. Mouth inconspicuous, mid-ventral. Pharynx prominent, large, distinct, between or slightly posterior to eyespots, 69–84 (77) µm long, 67–80 (73) µm wide. Oesophagus short 34–93 (60) µm. Intestine present as cyclocoel, bifurcation immediately anterodorsal to ventral sucker, strongly crenulated with intestinal crenulations very prominent in lateral reaches, proceeds in loop laterally from central oesophagus to level of anterior margin of pharynx, immediately passing lateroposteriorly towards each lateral margin, and following contour of body margin, recurving posteriorly and passing medially to envelop gonads and some vitelline follicles. Testes paired, spheroid, deeply lobed, symmetrical not contiguous, left testis surface area 9,781–25,692 (20,087) µm2, right testis surface area 6,084–25,521 (15,762) µm2. Seminal vesicle distinctly bipartite, composed of enclosed (by cyclocoel) and extracaecal portions; enclosed portion anterodextral to right testis, saccular, distinctly lobed or entire, 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 between eyespots, dextral to pharynx, forming naked ejaculatory duct distally. Genital pore median, on anterior margin of body. Ovary deeply lobed, 5,993–8,668 (7,621) µm2, sinistral to, but not contiguous with, left testis, oviduct passes medio-posteriorly from ovary. Uterine seminal receptacle present. Laurer’s canal unites with oviduct posterior to ovary, passes and joins vitelline reservoir further posteriorly, before opening dorsally, close to left testis, median portion of canal dilated, contains sperm and vitelline remnants. Uterus passes medially between anterior half of cyclocoel and testes, proceeds between right testis and saccular portion of seminal vesicle, then continues anteriorly to join ejaculatory duct at common genital pore; termination of uterus unspecialised. Vitellarium follicular; vitelline follicles dense, scattered in extracaecal and enclosed areas of body; extracaecal follicles fill posterior region of body, extend laterally to slightly to anterior level of the anterior margin of the cyclocoel, but not dense anterior, form 1–2 loose rows; enclosed follicles 26 or more in 2 masses but very dense and difficult to count. Vitelline reservoir immediately anterior to left testis. Eggs 51–92 (68) µm long, 31–83 (50) wide, tanned, unembryonated in utero. Excretory bladder saccular, opens posteriorly at small notch in middle of posterior margin, extends anteriorly in initially narrow tube; tube expands distally into large sac which lies largely ventral to cyclocoel, dextro-laterally directed anterior to posterior loop of cyclocoel.

Molecular data: Sequence data were obtained from the ITS2 rDNA locus of three specimens from Upeneus tragula from Moreton Bay, Queensland ( Table 2 ).

Remarks: Transversotrema licinum was described from two fish families from Moreton Bay ( Manter 1970) and subsequently from specimens from five families of fishes ( Hunter & Cribb 2012). Cribb et al. (1992) reported Upeneus tragula as a host of T. licinum but the present study has found that the complex of species similar to species from the T. licinum complex are not found on mullid fishes at any location. We have examined the specimens of Transversotrema from U. tragula at the Queensland Museum (QMGL12756 and GL12757) and found that they resemble the specimens used in this study and have the characteristic short oesophagus of the species from this complex; these specimens are here formally identified as representing T. cutmorei n. sp. Molecular data (ITS2 rDNA) from specimens from U. tragula from Moreton Bay place T. cutmorei n. sp. clearly within the clade of species from mullids. This is the only species of the mullid clade of transversotrematids known from Moreton Bay and the sole representative recorded from Upeneus (Cuvier & Valenciennes) . Transversotrema cutmorei n. sp. from U. tragula is morphologically similar to species of the T. licinum complex; but it is easily distinguished by its straighter oesophagus and the shape of the ovary. The overall body shape of T. cutmorei n. sp. is distinctive with angular lateral margins, and large, very dense vitelline follicles, especially those enclosed by the cyclocoel. It is distinguished from T. haasi , T. cabrarum n. sp., T. chevrarum n. sp., T. elegans , T. gigantica and T. lacerta by the absence of vitelline follicles across the anterior margin. No specimens resembling T. cutmorei n. sp. have been found to date from mullid fishes from Heron Island, Lizard Island or Ningaloo Reef, WA. Finally, molecular data (see below) distinguish T. cutmorei n. sp. from all the species from mullid fishes characterised here and all other transversotrematid species characterised by Hunter et al. (2010) and Hunter & Cribb (2012).

Figures

FIGURE 3. Transversotrema cutmorei n. sp. ex Upeneus tragula Moreton Bay, Queensland. Scale = 200 µm.