Sertulariida Maronna, Miranda, Peña Cantero, Barbeitos & Marques, 2016

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 : 48-49

Suborder Sertulariida Maronna, Miranda, Peña Cantero, Barbeitos & Marques, 2016 Sertularellidae Maronna, Miranda, Peña Cantero, Barbeitos & Marques, 2016

Sertularella diaphana (Allman, 1885)

Fig. 19D–E

Synonyms available from: Watson (2000).

Thuiaria distans Allman, 1877: 27 [secondary homonym; not Dynamena distans Lamouroux, 1816 ].

Sertularella lata – Vannucci, 1951a [not Sertularella lata (Bale, 1882) ] [polyp].

Description: Colonies erect, up to 8 cm high. Stem monosiphonic, divided pinnately on one plane into short internodes, nodes transverse to slightly oblique. Internodes with three cauline hydrothecae and one hydrocladium in the distal end. Cauline hydrothecae disposed one in the axis, one opposite to that, and the third below the hydrocladium. Hydrocladia alternate, arising at the stem in angles of 109–117 °. Hydrocladia long, slender, divided into internodes and carrying numerous hydrothecae. The first hydrocladial internode fairly long, slen- der, and ahydrothecate. Hydrothecae alternate, immersed on internode, separated laterally, each base reaching about half of the subsequent hydrothecae and distal end curved. Hydrothecae 179–230 µm high and 123–143 µm maximum diameter. Hydrothecal margin subcircular with four short, rounded, and equidistant cusps, one abcaulinar, one adcaulinar, and two laterals. Operculum with four triangular valves.

Material examined: PCS – three infertile colonies from dry and rainy seasons. CZUFS CNI-00023; CNI-00199.

Stations: PCS - 5, 8, 11, 12.

Bottom: graver, sand, and mud.

Distribution: Brazil – Fernando de Noronha ( Pires et al. 1992), Pernambuco ( Nutting 1904), Alagoas (Maximiliano M. Maronna unpub. data), Sergipe ( Allman 1888), and Bahia (Kelmo et al. 2003). World distribution – species well distributed in tropical and subtropical regions ( Vervoort 1993), considered virtually circumglobal ( Watson 2000).

Remarks: unknown substrate.

Sertularella peculiaris ( Leloup, 1935) Fig. 19F–H

Synonyms available from: Galea (2008).

Thyroscyphus intermedius f. peculiaris Leloup, 1935: 33 , figs 15–17. Sertularella conica – Migotto, 1996: 67, figs 12J–K.

Description: Colonies primarily erect, occasionally stolonal, up to 1.8 mm high, branched colonies up to 13 mm, all arising from a creeping hydrorhiza. Stolonal polyps are supported by a pedicel with perisarc waved along their entire length. Erect colonies geniculated, up to 14 branches carrying hydrothecae. The perisarc of the branches completely waved, except for a few smooth portions. Hydrothecae vessel shaped, bilaterally symmetrical, alternately arranged, 552–674 µm high and 347–420 µm maximum diameter, adnate to the stem for less than half of their length, wider at the base, narrowing towards the distal portion and widening again at the margin. Hydrothecae wall with 5–7 circular grooves. Rhomboid margin with rounded corners, and four-pointed triangular cusps. Operculum is composed of four triangular valves. Five wide distinct intrathecal cusps inserted just below the opening ( Fig. 22G ), one abcauline, two lateral-abcaulinar, and 2 lateral-adcaulinar. Stolonal hydrothecae are identical to that described above for the upright form.

Material examined: PCS – few infertile colonies from the dry and rainy seasons.CZUFS CNI-00200; CNI-00201; CNI-00202.

Stations: PCS – 5, 12, 15, 18.

Bottom: gravel, and sand.

Distribution: Brazil – São Paulo ( Migotto 1996) and Santa Catarina? ( Miranda et al. 2011). World distribution – South Carolina, Bermuda, Caribbean, and Brazil ( Galea 2008).

Taxonomic remarks: Galea (2008) presents the latest redescription of Sertularella peculiaris , a species described by Leloup (1935) as Thyroscyphus intermedius f. peculiaris and redescribed by Leloup (1974) as a new species, S. peculiaris . Descriptions and illustrations presented by Leloup (1935, 1974) and Galea (2008) show the existence of five wide intrathecal cusps as the main character for the identification of S. peculiaris . This characteristic led Galea (2008) to synonymize the records of S. conica of Calder (1991) and Migotto (1996), and others to S. peculiaris . Calder (1991) clearly mentioned the existence of five internal cusps; while Migotto (1996) does not describe the Brazilian material but he comments that it agrees with the described by Calder (1991). Calder (1991) and Migotto (1996) also mention the record of S. inconstans by Vanucci Mendes (1946) as correspondent to S. conica . The original description and illustrations of S. conica by Allman (1877) do not mention many characteristics of this species, including the existence or not of the intrathecal cusps. A review of the material identified as S. conica is necessary to verify its real distribution. Only the record of S. conica to São Paulo ( Migotto 1996) was synonymized by Galea (2008). The records of S. conica are mixed with the ones to S. tennella to Brazilian coast, but S. conica seams to have records to Espírito Santo ( Vannucci 1950, 1951a, Grohmann et al. 1997), Rio de Janeiro ( Vannucci 1951a, Miranda et al. 2015), São Paulo ( Vannucci Mendes 1946, Vannucci 1949, 1951a, Shimabukuro 2007, Silveira and Morandini 2011, Miranda et al. 2015), and Santa Catarina ( Miranda et al. 2011, 2015). From those records, the Vannucci Mendes (1946) and Vannucci (1949) are the ones with illustrations for the species and also the mention of three perisarcal thickenings above the hydrothecae opening, which did not match the description of S. conica , S. tenella or S. peculiaris . The study of Miranda et al. (2011) described the presence of submarginal cusps but did not say how many, only commenting that the material matched Calder’s (1991) description. As Calder’s (1991) records were synonymized to S. peculiaris , it seems likely that the record to Santa Catarina made by Miranda et al. (2011) refers to this species. A review of the Brazilian material is necessary to determine which species occur on the coast and their distribution.

Remarks: Colonizing algae and Bryozoa.

Figures

Figure 19. (A-C) Pycnotheca mirabilis: (A) general view of a stem with one gonotheca (red arrow); (B) detail of the gonotheca; (C) detail of a stem showing two hydrocladia and few hydrothecae; (D-E) Sertularella diaphana: (D) detail of a fragmented stem; (E) detail of a stem with three hydrocladia and several hydrothecae; (F-H) Sertularella peculiaris: (F) general view of a colony on Porifera; (G) superior view of the hydrotheca aperture showing the five intrathecal cusps characteristics of this species; (H) detail of a stem with two hydrothecae.

Figure 22. (A) Salacia tetracythara: general view of a stem showing few hydrocladia and hydrothecae; (B) Tridentata loculosa: detail of the stem with two hydrocladia and few hydrothecae; (C-E) Tridentata marginata: (C) general view of a stem with two gonothecae (red arrows); (D) detail of a stem with few hydrocladia and hydrothecae; (E) detail of one gonotheca; (F, I) Tridentata rugosissima: (F) detail of one pair of hydrothecae; (I) general view of a stem with several hydrothecae; (G-H) Tridentata turbinata: (G) detail of one pair of hydrothecae; (H) detail of a stem with hydrothecae.