Tytthosoceros lizardensis Newman and Cannon 1996

Khalili, Zahra, Rahimian, Hassan & Pazooki, Jamile, 2009, First record of the family Pseudocerotidae (Platyhelminthes, Polycladida, Cotylea) from the Persian Gulf, Iran, ZooKeys 31 (3), pp. 39-51 : 41-43

Tytthosoceros lizardensis Newman and Cannon 1996

Type location: Heron Island, southern Great Barrier Reef, Australia.

Type specimen: Queensland Museum, Brisbane, Australia WM QM (G 210716). Specimens examined: ZUTC Platy 1001, 1002.

Fifty-six specimens of this species were collected from two locations (Stations No. 1 and 2, Fig. 1, Table 1). Most specimens were found in groups of up to 20 individuals, under rubble in intertidal pools, and on an orange sponge ( Clione vastifera ). Most specimens autolysed during sampling or fixation and only four specimens remained intact after fixation procedure. The following description is based on those four specimens.

Description. Sizes of specimens range from 22 × 38 to 30 × 46 mm; background color variable, mottled light brown or olive green with cream mottling composed of dots, forming loose transverse streaks medially and laterally, darker medially sometimes with a tinge of light brown medially and on the pseudotentacles; narrow marginal bands, black then grey interrupted with short white transverse streaks of microdots at rim; submargin narrow, either cream or transparent grey ( Fig. 2); pseudotentacles earlike, small, cream with mottling of light brown or olive between ( Fig. 3 ); 70–80 cerebral eyes, arranged like a horseshoe, dorsal pseudotentaclular eyes, scattered, with about 35 eyes ( Figs 3 and 4 ); ventral surface of specimens cream with black rims, and very ruffled margins; anterior pharynx large and ruffled, 1/5 of the body length (8.6 mm), associated with 5–6 pairs of pharyngeal folds; mouth situated in the middle of the pharynx ( Fig. 6C ); intestine extending posteriorly, but not to the margin of the body; male and female gonopores posterior to pharynx, distinct sucker in mid-body proper ( Fig. 5 ).

Anatomy of Reproductive System ( Figs 6A, B , 7 ). Testes scattered throughout the body, vas deferens forming a network of thin tubes; single male copulatory apparatus with rounded-oblong seminal vesicle (456 × 336 µm), oval prostate oriented anterodorsally (120 × 96 µm), deep male antrum (192 µm), penis papilla with short stylet (120 × 72 µm); female copulatory apparatus with wide female atrium (120 µm) and cement glands.

Figures

Figure 3. Ear-like pseudotentacle in Tytthosoceros lizardensis: te pseudotentacular eyes ce cerebral eyes.

Figure 4. Eye arrangements on pseudotentacle in Tytthosoceros lizardensis: A dorsal surface: te pseudotentaclular eyes ce cerebral eyes B ventral surface.

Figure 5. Tytthosoceros lizardensis: A Drawing of the ventral surface B Photograph of the ventral surface su sucker mg male gonopore fg female gonopore ph pharynx.

Figure 6. Sagittal section of Tytthosoceros lizardensis: A male copulatory system B female copulatory system C pharynx: ma male antrum s stylet sv seminal vesicle p prostate fa female antrum fg female gonopore ce cement gland ph pharynx mo mouth.

Figure 7. Sagittal reconstruction of Tytthosoceros lizardensis: ma male antrum mg male gonopore s stylet sv seminal vesicle p prostate fa female antrum fg female gonopore ce cement gland ph pharynx mo mouth