Emprosthopharynx rasae Prudhoe, 1968

Ramos-Sánchez, Mariela, 2024, The polyclads (Platyhelminthes: Polycladida) from the Tropical Eastern Pacific: Commented checklist and description of a new species, European Journal of Taxonomy 962 (1), pp. 1-67 : 35

Emprosthopharynx rasae Prudhoe, 1968

Emprosthopharynx rasae Prudhoe, 1968: 408–411 , figs 1–3 (type locality: Kaneohe Bay, Oahu, Hawaiian Islands, United States).

Emprosthopharynx rasae – Pineda-López 1981: 67–72, figs 16–18 (description and new record between the María Madre and Isabela Islands, Nayarit, Mexico). — Lamothe-Argumedo et al. 1997: 15 (checklist).

Distribution

Hawaiian Islands and between the María Madre and Isabela Islands, Nayarit, Mexico.

Habitat

Symbiont ( Calcinus latens (Randall, 1840)) .

Remarks

Emprosthopharynx rasae was collected on shells of Trochus intextus Kiener, 1850 occupied by the hermit crab Calcinus latens . The worm is found around the abdomen of the pagurid, usually in the spiral cavity of the shell. The frequency of occurrence of the association is about one per 25–30 pagurids. Emprosthopharynx rasae differs from E. opisthoporus in dorsal coloration, distribution of submarginal eyes, and morphology of the seminal vesicle.

Prudhoe (1968) described the species in the Hawaiian Islands, noting its reddish-brown coloration with light margins and slight specks and spots that appear to be ovaries distributed under the body wall, a lack of nuchal tentacles, a prsence of submarginal eyes distributed throughout the body, sparse cerebral and tentacular eyes, a sparsely folded pharynx located immediately posterior to the brain, and gonopores separated and positioned in the last third of the body. The male reproductive tract features a seminal vesicle and pyriform prostatic vesicle oriented towards the anterior region of the body, anda a short inert penis papilla. The female reproductive tract has a bulbous vagina oriented towards the posterior region of the body and lacks Lang’s vesicle.

Pineda-López (1981) recorded the species in the islands of Nayarit, Mexico ( Lamothe-Argumedo et al. 1997), associated with a pagurid at a depth between 80 and 90 m. However, this author suggests a revision of more organisms because in his specimen he found variations in the size of the pharynx, and in the number of cerebral eyes, and he did not revise the male and female reproductive system of the specimens recorded for Nayarit.