Transversotrema manteri

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 : 31-32

Transversotrema manteri n. sp

( Fig. 11 )

Type-host: Caesio caerulaurea Lacepède , Lutjanidae ; Scissortail fusilier

Type-locality: Lizard Island, northern GBR, Queensland, Australia, (14°40´S, 145°28´E). Other locality: Ningaloo Reef, Western Australia, (21°30’S 114°30’E).

Other hosts: Caesio cuning (Bloch) Lutjanidae ; Red-bellied fusilier.

Site of infection: Beneath the scales

Material examined: Table 6

Molecular sequence data: ITS2 rDNA

GenBank accession numbers: see Table 2

Deposited specimens: Holotype QMG 231870 (ex Caesio caerulaurea coll. Cribb et al. Jun 2005), and paratypes QMG 231871 (ex Caesio cuning coll. Cribb, Bray & Adlard Apr 1997), QMG 231872 (ex Caesio cuning coll. Cribb, Bray & Adlard Apr 1997), QMG 231873 (ex Caesio cuning coll. Cribb et al. Jun 2005), QMG 231874 (ex Caesio cuning coll. Cribb et al. May 2004), QMG 231875 (ex Caesio cuning coll. Cribb et al. May 2004).

Etymology: this species is named after Dr. Harold Manter (1970) who described Transversotrema licinum from Moreton Bay, Queensland, in 1970.

Description: Based on measurements of 14 specimens from Caesioninae from Lizard Island and Ningaloo. Body transversely elongated, curved at extremities, strongly dorsoventrally flattened, 328–457 (407) long, 1,294– 1,912 (1,632) wide; average width/length range 4:1. Posterior margin wider than anterior margin. Pharynx to anterior margin 114–218 (154), distance from cyclocoel to posterior margin at mid-line 70–144 (99). Tegumental spines prominent. Eyespots prominent, 90–213 (145) apart, 7% of body width, anterior to pharynx; no pigment evident other than in eyespots. Ventral sucker posterior to eyespots, 1,430–2,631 (2,144) μm2. Mouth mid-ventral, inconspicuous. Pharynx between and slightly posterior to eyespots, 45–85 (61) long, 47–110 (68) wide. Oesophagus short, curved 53–96 (74). Caecal bifurcation dorsal to ventral sucker. Caeca form cyclocoel reaching laterally to envelop testes, ovary and some vitelline follicles. Margins of cyclocoel crenulated. Testes opposite, deeply lobed, left 6,042–35,991 (18,130) μm2; right 8,780–37,388 (16,870) μm2. Seminal vesicle formed of lobed, saccular enclosed portion and winding, tubular extracaecal portion. Enclosed portion distinctly lobed or entire, anterodextral 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, 2,903–12,939 (5,730) 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 numerous, confluent, lateral and posterior to cyclocoel, no follicles extend beyond lateral margin of cyclocoel along anterior margin; posterior follicles in rows of three to four. Enclosed follicles in two loosely assembled masses at each lateral extremity, 21–47 (34); follicles do not extend along posterior margin of cyclocoel posterior to testes. 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 95–145 (112.4) long, 39–74 (59.6) wide, 0–6 (2) in utero. Excretory bladder opens posteriorly at small notch in middle of posterior margin, extends anteriorly initially as narrow tube which then expands into large sac which passes ventral to cyclocoel anterior to which it becomes laterally directed.

Remarks: Transversotrema manteri n. sp. is similar to T. licinum in having a crescent or curved shape at the lateral margins however the overall shape is distinctly different. Transversotrema manteri n. sp. has a width to length ratio of 4:1 which is the largest of all species in this complex, and the distance between the cyclocoel and the posterior margin compared to body length is proportionally much greater than the same comparison in the other transversotrematid species (24% compared to 15–18%), including T. fusilieri n. sp. the other species recovered from caesioninae fishes at Lizard Island. This feature gives this species its unusual “sausage” shape. The only other species from the complex with a similar overall shape is T. atkinsoni n. sp. which is found on Heron Island and Ningaloo nemipterids and has been noted in specimens from sillaginids from estuarine waters near Gladstone, Queensland (discussed above). Like T. fusilieri n. sp., T. manteri n. sp. can be distinguished also by its small ventral sucker; but differs from that species in the distance from the cyclocoel to the posterior margin, the eye spot separation and the length of the oesophagus. The testes and ovary are small compared with those of T. borboleta n. sp., T. carmenae n. sp. and T. espanola n. sp. Transversotrema manteri n. sp. with its distinctive shape and body proportions can be easily distinguished from other transversotrematids. The sequence data confirms that this species is separate from all others.

Figures

FIGURE 11. Transversotrema manteri n. sp. ex Caesio caerulaurea Lizard Island. Scale = 200 μm.