Mysidobdella borealis

External morphology

Body round, elongated, and indistinctly divided into trachelosome and urosome. Average total length of mature individuals inclusive of suckers 9 mm (range 7-15 mm). Mouthpore centrally located in deeply cupped, bell-shaped oral sucker slightly eccentrically attached to trachelosome by unusually long and tapered nuchal constriction. Internal sucker surface behind membrane covered with small sucker-like structures. Sides of urosome parallel throughout its length, and trachelosome narrows only slightly anteriorly. Body surface smooth, lacking papillae, tubercles, gills, and pulsatile vesicles. Midbody segments 3(13) annulate. Caudal sucker slightly subterminal and no wider than maximum body width. One pair of eyes on nuchal constriction, but no ocelli on either sucker. Four ocelli, 2 dorsally and 2 ventrally, in each segment of urosome, 2 ocelli dorsally in posterior portion of segment XI. Pigmentation pattern in life somewhat variable, brown to reddish brown chromatophores scattered over most of body and suckers which give rise to uniform pigmentation pattern interrupted laterally to form metameric unpigmented areas on both trachelosome and urosome

Habitat & range

Habitat

Saltwater

Region

North Pole, North America

Recorded from

New Jersey, Bay of Fundy

Biology

On Mysids

Original description

Selensky, W. D. (1927). On a new Ichthybdellidae (Mysidobdella oculata n.g. n.sp.), a parasite on Crustacea. Proceedings of the Second Congress of Zoologists, Anatomists, and Histologists of USSR 2: 32-33, In: Severtsov, A.N., & B.S. Matveev (eds.), Trudy Vtorogo S´´Ezda Zoologov, Anatomov i Gistologov SSSR : Moskve 4-10 Maia 1925 g. [Proceedings of the Second Congress of Zoologists, Anatomists, and Histologists of USSR] (in Russian).