Calamactinia incubans, Ocaña & Çinar, 2018

Ocaña, Oscar & Çinar, Melih Ertan, 2018, Descriptions of two new genera, six new species and three new records of Anthozoa (Cnidaria) from the Sea of Marmara, Journal of Natural History 52 (35 - 36), pp. 2243-2282 : 2256-2259

Calamactinia incubans sp. nov.

( Figures 9 and 10 )

Material examined

Holotype, ESFM-CNI /2012-01, 28 June 2013, Sea of Marmara , K7, 40°35 ʹ 37 ʺ N, 27° 32 ʹ 48 ʺ E, 0.5 m, on Zostera marina beds, small expanded specimen, longitudinal sectioned for anatomical purposes, 0.7 cm × 0.3 cm; Paratype, ESFM-CNI /2012-02, 28 June 2013, Sea of Marmara , K7, 40°35 ʹ 37 ʺ N, 27°32 ʹ 48 ʺ E, 0.5 m, on Z. marina beds, 1 large specimen, well expanded and cross sectioned for study of anatomy, 0.5 – 1.5 cm × 0.5 – 0.8 cm, 3 specimens.

Description

Cuticle well developed, with thicker areas showing papillae-like structures; some sticking spots with small particules ( Figure 9 (a), 9(b)). Body and tentacles darkbrownish. Four tentacle cycles (6 + 6 + 12 + 24), but last one being quite incomplete Figure 9 (a)). Body with less than 30 tentacles; short and some of them with protuberances or swellings. Three mesentery cycles in a simple arrangement of 6 + 6 + 12; six being complete, reaching pharynx; six macrocnemes and 12 microcnemes being poorly developed ( Figure 9 (c), 9(f)). Two syphonoglyphs moderately developed ( Figure 9 (f)). Diffuse retractors extending along most of mesentery, but some of them poorly developed ( Figure 9 (c), 9(e), 9(f)). Parietobasilar rudimentary, but relatively easily discernible on microcnemes. No sphincter. Three small young specimens observed inside of an adult coelenteron ( Figure 9 (d)).

Cnidome

A survey of the cnidom is summarized in Table 3 and Figure 10 . Small homotrichs on the tentacles are very scarce. Penicilli B1 is present on the filaments. Larges spirulae on the filaments are also characteristic to many species in the family Actiniidae .

Remarks

Carlgren (1949) described the genus Calamactinia and its single species ( Calamactinia goughiensis Carlgren 1949 ) from the southern Atlantic waters of Gough Island. The general morphology of the new species described here, C. incubans sp. nov., resembles quite well that of C. goughiensis .

There is an ongoing discussion about whether the family members do have any syphonoglyph. There are genera without syphonoglyph, with one syphonoglyph, and even two syphonoglyphs as in the case of C. incubans sp. nov. Calamactinia incubans sp. nov. shares many characters with the genus Calamactinia and for this reason it was placed into this genus. However, several characters of C. incubans sp. nov. have not been reported on C. goughiensis . These characters include the presence of papillae on the cuticle, swellings on tentacles and diffuse retractors. All of these differences might be enough to erect a different genus to accommodate the new species from the Sea of Marmara . However, the absence of detailed description of C. goughiensis including the cnidom morphology makes it inconvenient at this moment to describe a new genus and thus we decided to amend characters to the description of the genus Calamactinia .

Habitat

This species was found on Zostera beds in shallow waters. Remnants of hermit crab were found in the coelenteron.

Reproduction

Three small young specimens observed inside of an adult coelenteron. It incubates young specimens in the coelenteron.

Etymology

The specific name emphasizes the incubation of young specimens inside adults.

Figures

Figure 9. Calamactinia incubans sp. nov. (a) Oral view of a specimen; (b) lateral view of a specimen; (c) retractors at the mesenteries level; (d) juvenile inside the colenteron; (e) longitudinal section of a specimen without sphincter; (f) cross section of pharynx showing retractors, two pair of directives attached to syphonoglyphs and papillae structures in the ectoderm. Scale bars: a = 3.6 mm; b = 3.2 mm; c = 1.6 mm; d = 2.3 mm; e = 1.8 mm; f = 1.3 mm. Abbreviations: si: syphonoglyphs; ph: pharynx; m: mesogloea; ec: ectoderm; en: endoderm: fi: filaments; mi: microcnemes; ma: macrocnemes; d: directives, p: papilla.

Figure 10. Calamactinia incubans sp. nov. Cnidom morphology in different parts of the body. (a, b) Spirocyst; (c) homotrich; (d) spirulae 1; (e) spirulae 2; (f) penicilli B1; (g) penicilli A; (h–j) spirulae. Scale bar: 13 µm.