Aplidium bermudae ( Van Name, 1902 )

Fortaleza, Maria Tarciana Vieira & Lotufo, Tito Monteiro Da Cruz, 2018, Polyclinidae (Ascidiacea: Aplousobranchia) from the Gulf of Mexico, collected during the “ Hourglass ” cruises (1965 - 1967), Zootaxa 4422 (4), pp. 519-536 : 522-524

Aplidium bermudae ( Van Name, 1902)

(Figuras 4, 5)

Amaroucium bermudae Van Name, 1902: 352 ; 1921: 305; 1945:40.

Aplidium bermudae Monniot, 1972: 949 ; 1974: 1288. Monniot and Monniot, 1984: 570.

Examined material: collected in 1/9/1967; 7/4/1966 and 3/3/1967, respectively; 73.2 m, 27°37’N, 084°13’W, specimens # EJ-67-80; # EJ-66-118 and # EJ-67-316.

Description: Colonies of lobular shape and irregular surface, 3.2 to 5.5 cm high. Tunic brownish or whitish, of cartilaginous consistency. Attachment area of variable thickness, with some sediment and shell fragments in the attachment. Zooids distributed irregularly without evidence of systems organization.

Zooids were contracted, cream colored, with thorax and abdomen together measuring 1.10–3.91 mm and postabdomen 0.42–7.03 mm. Branchial siphon 0.16–0.29 mm long, exhibiting six rounded or sharp lobes. Atrial opening is small and slightly lobed, located between the second and fourth rows of stigmata. Atrial languet simple, up to 0.48 mm long. Zooids musculature evident formed by approximately 20 to 30 thin parallel longitudinal bundles along each side of the zooid. Pharynx with 16–21 rows of stigmata. The number of stigmata per row could not be counted. Esophagus short, connected to a slightly elongated stomach, flattened in the anterior and posterior ends, with thin walls, exhibiting 10 to 17 irregular longitudinal folds, and four to five transversal ones. The esophagus and stomach together occupy almost the whole length of the abdomen. Posterior stomach absent. Anal opening located between the level of the eleventh and fourteenth rows of stigmata. Post-abdomen of variable size and very opaque, impairing gonad visualization. Several small follicles distributed around the edges of the postabdomen. Only one poorly developed larva was found in the colony, measuring 0.80 mm, and tail wound ¾ way around the trunk.

Remarks. Aplidium bermudae was originally described with 18 rows of stigmata and transversal folds in the stomach ( Van Name, 1902). However, some authors observed variations in some important characters, such as the number of stigmata rows varying from 13 ( Monniot, 1974; Monniot & Monniot, 1984) to 15 and 17 ( Monniot, 1972; Van Name, 1921; Van Name, 1945), and in the stomach structure, described as having 8 longitudinal folds together with transversal structures ( Monniot, 1972) or 10 to 18 longitudinal folds ( Van Name, 1921; Van Name, 1945). The deposited material in the National Museum of Natural History (NMNH) collection was examined and specimens identified as A. bermudae had 12 to 14 (NMNH 7011), 15 to 16 (NMNH 1300) or 22 rows of stigmata in the pharynx (NMNH 14843); and 10 (NMNH 1300), 12 (NMNH 7011) or 14 longitudinal folds in the stomach (NMNH 7157). Due to the considerable variation observed, it is probable that more than one species were lumped together and a more thorough review including type material is necessary.