Antennella curvitheca Fraser, 1937

Castro Mendonça, Luana M., Parisotto Guimarães, Carmen R. & Haddad, Maria A., 2022, Taxonomy and diversity of hydroids (Cnidaria: Hydrozoa) of Sergipe, Northeast Brazil, Zoologia (e 21032) 39, pp. 1-65 : 37

Antennella curvitheca Fraser, 1937

Fig. 17D–E

Antennella curvitheca Fraser, 1937a: 4 , pl. 2, fig. 7.

Antennella curvitheca –Van Gemerden-Hoogeveen, 1965: 56, fig. 32, 33.

Antennella curvitheca – Schuchert, 1997: 38–40, fig. 13.

Description: Colonies with unbranched hydrocladia arising directly from a creeping hydrorhiza, up to 7 mm high. Hydrocladium is composed of several internodes, separated alternately by oblique and transverse nodes. First segments of hydrocladium smooth, without hydrothecae or nematothecae, followed alternately by one hydrotheca and four nematothecae, a median, a pair of lateral and a superior (not axillar); and one intersegment with a single nematotheca or, less frequently, without nematotheca. Hydrothecae cylindrical, 94–137 µm high, 134–184 µm wide, thick perisarc, adcaulinar portion adnate to the hydrocladium by half of their length, abcaulinar wall straight and adcaulinar with a distinct concave curve. Basal region of hydrothecae with one internal cusp projected to the adcaulinar cavity. All nematothecae two-chambered. Median nematothecae sessile, short and curved, reaching the hydrothecal base. Lateral nematothecae conical, formed by a pedicel shorter than the chamber, reaching almost half of the hydrothecae. Nematothecae superior to the hydrothecae and intersegment similar, mobile, with the inferior and superior chamber with the same size or the inferior one a little bigger.

Material examined: PCS – few infertile colonies, from the dry and rainy seasons. CZUFS CNI-00168; CNI-00169; CNI-00269.

Stations: PCS – 4, 5, 6, 7, 13, 15, 18.

Bottom: gravel, sand, and mud.

Distribution: Brazil – Bahia ( Grohmann et al. 2003). World distribution – recorded from the Caribbean, Porto Rico, and Ilha Nevis ( Schuchert 1997).

Remarks: Found on algae.

Figures

Figure 17. (A-C) Antennella incerta: (A) general view of a colony on algae; (B) detail of a hydrocladium showing few hydrothecae, nematothecae and a gonotheca (Go - red arrow); (C) detail of an internode with one hydrotheca and nematothecae; (D-E) Antennella curvitheca: (D) detail of a colony on algae; (E) detail of a hydrocladium showing one hydrotheca and nematothecae; (F-G) Antennella secundaria: (F) general view of a colony on algae: (G) detail of a hydrocladium showing one hydrotheca and nematothecae. Details on the images: a – lateral nematotheca, b – medial nematotheca, c – upper axillar nematotheca, d – intersegmental nematotheca, e – upper non-axillar nematotheca, f – intrathecal cusp.