Tethys willcoxi var. perviridis Pilsbry, 1895

Cunha, Carlo M. & Rosenberg, Gary, 2019, Type specimens of Aplysiida (Gastropoda, Heterobranchia) in the Academy of Natural Sciences of Philadelphia, with taxonomic remarks, Zoosystematics and Evolution 95 (2), pp. 361-372 : 361

Tethys willcoxi var. perviridis Pilsbry, 1895 Figure 4 A–E

Tethys willcoxi var. perviridis Pilsbry, 1895: 81-82; 1896b, pl. 55, figs 1-4.

Type locality.

Cape May, New Jersey [USA].

Type material.

Holotype (monotypy): ANSP A2250 (ca 105 mm long preserved, shell 60 mm long; H. Lemon coll., 25/x/1894). Pilsbry stated that he examined a single specimen.

Remarks.

Aplysiidans possess a large gland near the mantle floor, called the opaline gland (or gland of Bohadsch), that produces a milky liquid when the animal is disturbed ( Gosliner 1994). The gland can be multiporous (e.g. A. depilans , A. juliana and A. parvula ) or uniporous (e.g. A. dactylomela and A. fasciata ) ( Beeman 1968; Cunha and Simone 2019; pers obs.). The opaline gland in Aplysia perviridis is unique in having both conditions, uniporous and multiparous (figs 32, 33). Pilsbry (1895) described the opaline gland as "projecting externally as a pedunculated oval body", but that appears to be the result of contraction upon fixation, as suggested by Pilsbry: "but perhaps evaginated, in which case it would have one large orifice".

The opaline gland of a single young specimen collected in 1950 from Sea Isle City, New Jersey, which is about 35 km north of the type locality was dissected to confirm this condition (ANSP A2235, ~60 mm long preserved). Despite the lack of a "pedunculated oval body" the condition of gland is the same (Fig. 4B, C). The multiporous part is more developed in the holotype than in the young specimen.

Aplysia perviridis (Pilsbry, 1895) was accepted as a synonym of A. willcoxi Heilprin, 1886 by Eales (1960). However, with the anatomical differences of the opaline gland, we treat it as a valid species herein.

Current systematic position.

Aplysia perviridis (Pilsbry, 1895) comb. nov.