Transversotrema espanola

Hunter, Janet A. & Cribb, Thomas H., 2012, A cryptic complex of species related to Transversotrema licinum Manter, 1970 from fishes of the Indo-West Pacific, including descriptions of ten new species of Transversotrema Witenberg, 1944 (Digenea: Transversotrematidae), Zootaxa 3176, pp. 1-44 : 29-30

Transversotrema espanola n. sp

( Fig. 9 )

Syn. T. licinum of Cribb et al. 1997, in part

Type-host: Lutjanidae : Lutjanus carponotatus (Forsskål) , Spanish flag snapper.

Type-locality: Heron Island, southern GBR, Queensland, Australia. (23°27’S 151°55’E)

Other locality: Lizard Island, northern GBR Queensland, Australia, (14°40’S 145°28’E).

Other hosts: Lutjanus gibbus, (Forsskål) , Paddletail Haemulidae , Diagramma labiosum (Macleay) , Painted sweetlips.

Site of infection: Beneath the scales

Material examined: Table 8 & 9

Molecular sequence data: ITS2 rDNA

GenBank accession numbers: Table 2

Deposited specimens: Holotype QM G231859 (ex L. carponotatus HI coll. Ingram 28 Apr 2003) and paratypes QM G 231860 (ex L. carponotatus HI coll. Ingram 28 Apr 2003), QM G231861 (ex L. carponotatus HI coll. Cribb et al. Apr 1997), QM G231862 (ex L. carponotatus HI coll. Ingram 30 May 2003), QM G231863 (ex L. carponotatus HI coll. Ingram 30 May 2003).

Etymology: The name for this transversotrematid species is a reference to the common name for the type host, Lutjanus carponotatus, Spanish flag.

Description: Based on measurements of 9 specimens from lutjanines from Heron

Island and Lizard Island. Body transversely elongated, strongly dorsoventrally flattened, crescent–shaped and widest at anterior margin, 539–736 (650) long, 1,599–2,510 (1,938) wide; average width/length range 3:1. Pharynx to anterior margin, 197–266 (228); cyclocoel to posterior margin at midline, 94–130 (113). Tegumental spines prominent. Eyespots prominent, 126–196 (152) apart, 8% of body width; no pigment evident other than in eyespots. Ventral sucker well posterior to eyespots, 3,784–6,200 (4,704) μm2. Mouth mid-ventral, inconspicuous. Pharynx between and slightly posterior to eyespots, 71–92 (80) long, 83–105 (95) wide. Oesophagus curved 82–135 (107). Caecal bifurcation dorsal to ventral sucker. Caeca form cyclocoel reaching laterally to envelop testes, ovary and some vitelline follicles. Testes opposite, deeply lobed, left 17,561–48,328 (28,484) μm2; right 15,967–44,903 (26,501) μm2. Seminal vesicle formed of lobed, saccular enclosed portion and winding, tubular extracaecal portion. Enclosed portion distinctly lobed or entire, antero-dextral to right of testis, constricts distally to form narrow duct that passes ventral to cyclocoel to join tubular portion. Tubular portion of seminal vesicle passes mediad along cyclocoel then turns anteriorly and passes between eyespots dextral to pharynx, loops and passes to common genital pore where it unites with uterus without any specialisation. Common genital pore precisely in midline on anterior margin of worm. Ovary sinistral to left testis, with five prominent, extended lobes, 7,358–14,623 (9,920) μm2. Oviduct passes medio-posteriorly, unites with Laurer’s canal and duct from oviduct passes vitelline reservoir, Laurer’s canal then passes posteriorly to open dorsally close to left testis; median portion dilated, contains sperm or vitelline remnants. Vitelline reservoir immediately anterior to left testis. Extracaecal vitelline follicles small, confluent, lateral and posterior to cyclocoel, three or four follicles scattered along anterior margin of cyclocoel; posterior follicles in compact uneven rows of three gradually becoming more scattered at lateral margins with few follicles extending beyond level of cyclocoel; enclosed follicles in two loosely assembled masses at each lateral extremity, 31–47 (39); three or four follicles scattered posterior to testes along inner margins of posterior cyclocoel. Uterus passes medially between anterior half of cyclocoel and testes then between right testis and saccular portion of seminal vesicle. Proximal portions of uterus act as seminal receptacle. Eggs 99–121 (104) long, 38–52 (48.9) wide, 1–11 (6) in utero. Excretory bladder opens posteriorly at small notch in middle of posterior margin, extends anteriorly in initially narrow tube which then expands into large sac which passes ventral to cyclocoel anterior to which it becomes laterally directed.

Remarks: Transversotrema espanola n. sp. although crescent-shaped like T. licinum is distinguished from that species by a shorter pharynx and smaller ventral sucker. All other measurements are larger. The vitelline follicles of T. espanola n. sp do not extend into the anterior margin far beyond the line of the cyclocoel and form a thick closely assembled band of three to four rows confluent along the posterior margin in a distinctive pattern. Transversotrema licinum , T. atkinsoni n. sp., T. borboleta n. sp., T. carmena n. sp. and T. damsella n. sp. have rows of two follicles adjacent to the excretory pore extending to three follicles towards the lateral margins. The average length and width, and the average size of the testes and ovary of T. espanola are larger than all of the above species with the exception of T. damsella n. sp. however it is distinctly different from that species. These characters combined with molecular data separate it from other T. licinum- like transversotrematids. Cribb et al. (1992) reported T. licinum from eight specimens from L. carponotatus from Heron Island; from examination of those specimens at Queensland Museum we found their morphology to be consistent with T. espanola n. sp. and attribute them to this new species.

Figures

FIGURE 9. Transversotrema espanola n. sp. ex Lutjanus carponotatus Heron Island. Scale = 200 μm.