Cephalodasys interinsularis, Kieneke, Alexander, Schmidt-Rhaesa, Andreas & Hochberg, Rick, 2015

Kieneke, Alexander, Schmidt-Rhaesa, Andreas & Hochberg, Rick, 2015, A new species of Cephalodasys (Gastrotricha, Macrodasyida) from the Caribbean Sea with a determination key to species of the genus, Zootaxa 3947 (3), pp. 367-385 : 368-369

Genus Cephalodasys Remane, 1926

Hummon (1974a) provided the first diagnosis of the genus beyond Remane’s (1926) original description of Cephalodasys maximus . Since then, Cephalodasys was reclassified from the Lepidodasyidae to the Cephalodasyidae (see Hummon & Todaro 2010) but a rediagnosis of the genus was not provided. Below, we present an emended version of Hummon’s (1974a) original classification. Primarily, information concerning the reproductive system and the external cilia has been added.

Emended diagnosis. Cephalodasyidae with head delineated from trunk by means of a constriction; posterior end broadly expanded, often rounded or truncated, or tapered into a medial process. Anterior adhesive tubes (TbA) 2–7 per side, located posterior to buccal cavity in vicinity of neck constriction and often borne on extensible feet; ventrolateral adhesive tubes (TbVL) present, with several to many pairs occurring along pharyngeal and intestinal regions, but may be absent from pharyngeal region; dorsal adhesive tubes (TbD) mostly absent, so far only known from one species; posterior adhesive tubes (TbP) 10–20, rarely fewer, located on lateral and posterior borders of caudal end, and may be separated into groups on either side of midline or may merge almost indistinguishably with TbVL. Cuticle thin, without armament, but often with granular appearance, epidermal glands are mostly absent but exist in two species. Pharyngeal length in adults about one-third total body length; intestine more or less divisible into broad anterior secretory region and narrower posterior absorptive region. An unpaired dorsal ovary is located posterior to U50, eggs mature in a caudal direction, one or few eggs mature at a time; paired testes at both sides of the intestine in the anterior part of the trunk (approximately U25–U50), caudally directed sperm ducts often fuse into a ventral unpaired gonopore; frontal organ present, caudal organ only known in some species. Locomotory cilia cover entire ventral region of head and then extend posteriorly as two longitudinal columns along the neck and trunk; both columns fuse into a narrow field of cilia at the posterior end. Ring-shaped field of sensory cilia on the dorsal side of the head. Stiff sensory cilia evenly spaced along the trunk in lateral and/or dorsolateral rows.

FIGURE 1. Lee Stocking Island ( Bahamas) at the southwestern edge of the Exuma Sound, Caribbean Sea with the locus typicus of Cephalodasys interinsularis n. sp. (station LSI09). Areas around the islands marked with different shades of grey indicate major sublittoral sandbars. Black areas on the islands are lagoons or ponds. The Caribbean Marine Research Center (CMRC) is the field station of the Perry Institute for Marine Science. Map modified from White and Curran (1993) and emended with information from satellite images accessed via Google TM earth.