Taxonomy and diversity of hydroids (Cnidaria: Hydrozoa) of Sergipe, Northeast Brazil Author Castro Mendonça, Luana M. Instituto de Ciências Biológicas e da Saúde, Universidade Federal de Alagoas. Avenida Lourival Melo Mota, & Programa de Pós-Graduação em Zoologia, Departamento de Zoologia, Setor de Ciências Biológicas, Universidade Federal do Paraná. Caixa Postal 19020, 81531 - 980 Curitiba, PR, Brazil. mahaddad. 2014 @ gmail. com Author Parisotto Guimarães, Carmen R. Departamento de Biologia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de Sergipe. Avenida carmenparisotto@gmail.com Author Haddad, Maria A. Instituto de Ciências Biológicas e da Saúde, Universidade Federal de Alagoas. Avenida Lourival Melo Mota, text Zoologia 2022 e 21032 2022-11-25 39 1 65 http://dx.doi.org/10.1590/s1984-4689.v39.e21032 journal article 10.1590/S1984-4689.v39.e21032 1984-4689 13176475 2B189EA2-803A-428C-AE26-C3669A5F3100 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.