Transversotrema cardinalis

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 : 24-25

Transversotrema cardinalis n. sp

( Fig. 6 )

Type-host: Lutjanus bohar (Forsskål) (Lutjanidae) , Two-spot red snapper.

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

Other hosts: Lutjanus carponotatus (Richardson) , Spanish flag snapper; Lutjanus fulviflamma (Forsskål) ; Dory snapper; Lutjanus argentimaculatus (Forsskål) , Mangrove red snapper; Lutjanus gibbus, (Forsskål) , Humpback red snapper; Lutjanus monostigma (Cuvier) , Onespot Seaperch; Lutjanus russelli (Bleeker) Russell’s snapper; Lutjanus quinquelineatus, (Bloch) Five-lined snapper; Diagramma labiosum, (Macleay) , Painted sweetlips.

Site: Beneath the scales

Material examined: see Table 8 & 9

Molecular sequence data: ITS2 rDNA.

GenBank accession numbers: Table 2

Deposited specimens: Holotype QM G 321837 (ex L. bohar LI coll. Cribb et al. 1 Jun 2005) and paratypes QMG 231838 (ex L. argentimaculatus LI coll. Cribb et al. 4 My 2004), QMG 231839 (ex L. fulvus LI coll. Cribb et al. Jun 2005), QM G231840 (ex L. gibbus LI coll. Cribb et al. 4 may 2004), QM G231841 (ex L. gibbus LI coll. Cribb et al. 4 may 2004), QM G231842 (ex L. monostigma LI coll. Cribb et al. Apr 2006), QM G231843 (ex L. russelli LI coll. Cribb et al. 5 Jun 2005), QM G231844 (ex D. labiosum LI coll. Cribb et al. Apr 2006), QM G231845 (ex D. labiosum LI coll. Cribb et al. May 2007), QM G231846 (ex D. labiosum LI coll. Cribb et al. Jun 2007).

Etymology: The type host is commonly called the red snapper hence the name cardinalis from the Latin word for red.

Description: Based on measurements of 23 specimens from lutjanines from Lizard Island. Body transversely elongated, D–shaped, strongly dorsoventrally flattened, 494–1,597 (973) long, 1,474–4,081 (2562) wide; average width/length range 2.5:1. Pharynx to anterior margin, 175–692 (428); cyclocoel to posterior margin at midline, 173–169 (144). Tegumental spines prominent. Eyespots prominent, 94–359(184) apart, 8% of body width apart; no pigment evident other than in eyespots. Ventral sucker well posterior to eyespots, 3,449–12,236 (6,363) μm2. Mouth mid-ventral, inconspicuous. Pharynx posterior to eyespots, 71–198 (125) long, 67–139 (102) wide. Oesophagus curved. Caecal bifurcation dorsal to ventral sucker. Caeca–form cyclocoel reaching laterally to envelop testes, ovary and some vitelline follicles. Testes opposite, deeply lobed, left 11,776–86,090 (40,001) μm2; right 12,024– 88,232 (40,246) 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, 3,851–24,156 (12,865) 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 to the lateral margins and posterior to cyclocoel, three or four follicles scattered along anterior margin of cyclocoel; posterior follicles in rows of two. Enclosed follicles in two loosely assembled masses at each lateral extremity, 10–46 (22); 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 not large compared to body size, 87–133 (110) long and 39–48 (44.3) wide, usually 1–6 (3) in utero, but often many 10–44 (22) observed in large specimens. 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 cardinalis n. sp. is markedly distinct from T. licinum and all other transversotrematids. It is D-shaped, widest at the anterior margin and by far the largest in this complex as most measurements exceed those for other species in this study both in range and average (a notable exception is the ovary of T. damsella n. sp., described below, which is larger). The eyespots, the distance between which occupies only 8% of the body width are distinctively anterior to the pharynx whereas the eyespots in T. licinum and the other transversotrematids from the complex are on either side of or very slightly anterior to the pharynx. Manter (1970) described the anterior portion of the seminal vesicle as coiled (p. 488); however the anterior section of the vesicle in T. cardinalis n. sp. has one loop. Vitelline follicles are noticeably absent from the anterior margin. Overall size and body shape, single-looped seminal vesicle and the position of the eyespots distinguish this species from all others.

Figures

FIGURE 6. Transversotrema cardinalis n. sp. ex Lutjanus bohar. Lizard Island. Scale = 200 μm.