Kirchenpaueriidae Stechow, 1921

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 : 43

Kirchenpaueriidae Stechow, 1921 Pycnotheca mirabilis ( Allman, 1883)

Fig. 19A–C

Synonyms available from: Watson (2005).

Diplocheilus mirabili s Allman, 1883: 49, pl. 8, figs 4–7.

Kirchenpaueria mirabilis var. robusta – Vannucci Mendes, 1946, – Vannucci, 1950 [polyp].

Description: Colonies erect, mostly fragmented, up to 14 mm high, arising from a tubular and creeping hydrorhiza. Stem monosiphonic with the basal region without hydrothecae or nematothecae, divided into one or two segments separated by transverse nodes. The posterior region is formed by hydrocladia arising alternately from the stem and separated by intersegment with oblique nodes in both extremities, one nematotheca in each axis formed by the intersegment and the hydrocladia. Hydrocladia is composed of regions with hydrothecae and intersegments, the first composed by hydrothecae and one median inferior nematotheca and the second one without hydrothecae or nematothecae, those separated by oblique nodes. Hydrothecae occupying almost the entire segment, 179–228 µm high, 200–257 µm of marginal wide, almost entirely adnate to the hydrocladia, with a short free portion next to the margin. Abcaulinar hydrothecal wall concave in the distal portion, below the margin, with long triangular septa that pass obliquely in the middle of the hydrothecae, behind the adcaulinar margin. Median inferior nematothecae sessile, with one chamber, not reaching the hydrothecae base. A single colony was found with one gonotheca, this inserted in a short pedicel at the basal portion of the stem. Gonotheca in the form of an inverted cone, 565 µm high, 690 µm wide, slightly flat laterally, larger in the distal portion, margin smooth, aperture flat towards the gonothecal interior.

Material examined: PCS – few colonies, one of them with one gonotheca, from the dry and rainy seasons. CZUFS CNI-00017; CNI-00185; CNI-00355; CNI-00356.

Stations: PCS – 4, 5, 6, 10, 12, 13, 15, 18.

Bottom: gravel, sand, and mud.

Distribution: Brazil – Paraíba (Felipe F. Campos unpub. data), Espírito Santo ( Grohmann et al. 2003), Rio de Janeiro ( Vannucci Mendes 1946, Vannucci 1951a), São Paulo ( Vannucci Mendes 1946, Vannucci 1950, Silveira and Morandini 2011), Paraná (Maria A. Haddad unpub. data), and Santa Catarina ( Miranda et al. 2011, Bouzon et al. 2012). World distribution – records from the Atlantic, Indian, and Pacific Oceans ( Millard 1975, Watson 2005, Ansín Agís et al. 2014).

Taxonomic remarks: Gonotheca found in specimens from Sergipe differs from the description presented by Millard (1975) and Watson (2005), however, the last author mentioned that the gonotheca described was male, resembling the one shown in Millard (1975) that did not mention the sex of the specimens. This could mean that the fertile material found in Sergipe is female.

Remarks: Found on algae.

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.