Transversotrema carmenae, Hunter, Janet A. & Cribb, Thomas H., 2012

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 : 26-27

Transversotrema carmenae n. sp.

( Fig. 7 )

Type-host: Scolopsis margaritifer (Cuvier) (Nemipteridae) . Pearly monocle bream

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

Other localities: nil

Other hosts: Scolopsis affinis Peters , Peters’ monocle bream; Scolopsis bilineatus (Bloch) , Two-lined monocle bream; Scolopsis lineata Quoy & Gaimard, Striped monocle beam; Scolopsis monogramma (Cuvier) , monogrammed monocle bream

Site: Beneath the scales

Material examined: see Table 7

Molecular sequence data: ITS2 rDNA

GenBank accession numbers: Table 2

Deposited specimens: Holotype QM G 231847(ex S. margaritifer LI coll. Cribb et al. May 2004), and paratypes QM G231848 (ex S. monogramma LI coll. Cribb et al. Jun 2005), QM G 231849 (ex S. monogramma LI coll. Cribb et al. Jun 2005), QM G 231850 (ex S. monogramma LI coll. Cribb, Bray & Adlard Apr 1997), QM G 231851 (ex S. margaritifer LI coll. Cribb et al. May 2004), QM G 231852 QM G 231853 (ex S. bilineatus LI coll. Cribb et al. Jun 2005), QM G 231853 (ex S. affinis LI coll. Cribb et al. Jun 2005).

Etymology: This species is named after Carmen Velasquez in recognition of her research on transversotrematids in the Philippines.

Description: Based on measurements of 15 specimens from nemipterids from Lizard Island. Body transversely elongated, strongly dorsoventrally flattened, 320–920 (533) long, 880–2170 (1460) wide; width/length range 2.7:1. Pharynx to anterior margin 134–207 (142); cyclocoel to posterior margin 53–138 (82). Anterior margin curved. Tegumental spines prominent. Eyespots prominent, 131–226 (171) apart, 9.7–12.8 (11%) of body width; positioned beside pharynx; no pigment evident other than in eyespots. Ventral sucker well posterior to eyespots, 2,650–4,479 (3,702 μm2). Mouth mid-ventral, inconspicuous. Pharynx between eyespots, 51–98 (77) long, 53–103 (72) wide. Pharynx to anterior margin, 136–257 (176). Cyclocoel to posterior margin 53–148 (106). Oesophagus curved 53–103 (72) long. Caecal bifurcation dorsal to ventral sucker. Caeca form cyclocoel reaching laterally to envelop testes, ovary and some vitelline follicles. Testes opposite, deeply lobed, left, 12,683–38,021 (21,703) μm2; right 11,678–43,199 (20,916) 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 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 usually five prominent extended lobes 4,257–15,944 (7079) μm2. Oviduct passes medio-posteriorly, unites with Laurer’s canal and duct from oviduct passes vitelline reservoir, 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, do not extend anterior to anterior margin of cyclocoel; posterior follicles in rows of three or four; enclosed follicles in two loosely assembled masses at each lateral extremity, 18–46 (27) with few follicles scattered posterior to testes along inner margins of 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 tanned, 69–118 (95) long and 30–56 (46) wide, few in utero (1–4). 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 carmenae n. sp. is similar to T. licinum but has a straighter anterior margin and is slightly D-shaped rather than crescent-shaped. This species is distinguished from T. licinum by a larger measurements for many characters for example length, width, ventral sucker area and oesophagus length, and the average width of the pharynx measurements is greater than the upper limit of T. licinum specimens from Manter’s (1970) description (p. 487). The only measurement where T. licinum exceeds T. carmenae n. sp. is the pharynx to the anterior margin. When compared to T. atkinsoni n. sp. it is noted that T. carmenae n. sp. has smaller upper range and average measurements for most characters, but in particular measurements of the testes and ovaries of T. atkinsoni n. sp. are significantly greater. The overall body shape is noticeably different. Transversotrema atkinsoni n. sp. from Heron Island and Ningaloo Reef, and T. carmenae n. sp. from Lizard Island are from Nemipteridae fishes and have been found from the same species of fishes at these locations, with the exception of Scolopsis margaritifer which has no record of transversotrematids from Heron Island. Molecular data also shows that they are different species. Transversotrema carmenae n. sp. is distinguished from T. borboleta n. sp. in having a shorter distance from the pharynx to the anterior margin, and a longer pharynx and oesophagus.

Figures

FIGURE 7. Transversotrema carmenae n. sp. ex Scolopsis margaritifer Lizard Island. Scale = 200 μm.