Sertularella polyzonias

• Main Author: Calder, Dale R.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2012
• Subjects: Biodiversity; Taxonomy; Animalia; Cnidaria; Hydrozoa; Leptothecata; Sertularellidae; Sertularella; Sertularella polyzonias; Moura; Rowe; Rugosa; North Atlantic
• Online Access: https://zenodo.org/record/5248532; https://doi.org/10.5281/zenodo.5248532

Sertularella polyzonias (Linnaeus, 1758) Fig. 36 Sertularia polyzonias Linnaeus, 1758: 813. Sertularella polyzonias.— Segerstedt, 1889: 16, 26.— Jäderholm, 1909: 100, pl. 11, fig. 12.— Rees & Rowe, 1969: 18.— Jägerskiöld, 1971: 64.— Cornelius, 1979: 288. Type locality. England: Kent, north coast (Cornelius 1979: 288). Museum material. Kosterhavet, 58°52.424’N, 11°06.178’E, 35– 11 m, 06.ix.2010, biological dredge, R / V Nereus, several colonies and colony fragments, up to 2.3 cm high, on bryozoans and algae, without gonothecae, ROMIZ B3886. Remarks. Sertularella polyzonias (Linnaeus, 1758) can be somewhat difficult to distinguish from S. gayi (Lamouroux, 1821), which also occurs in northwestern Europe. According to Ramil & Vervoort (1992) and Ramil et al. (1992), S. polyzonias differs from S. gayi in: (1) the form of the hydrocaulus, which is indistinct and monosiphonic instead of distinct and strongly polysiphonic; (2) the type of branching, which is irregular instead of regularly pinnate and in one plane; (3) the shape of the adcauline hydrothecal wall, which is smooth or minimally undulated instead of being more distinctly wavy; (4) the number of cusps flanking the aperture of the gonotheca, with four instead of two. Cornelius (1995b) noted that variations have been noted in these characters, but he retained both species as valid. In addition to morphology, molecular differences have been noted in specimens assigned to the two species (Moura et al. 2008, 2011). FIGURE 37. Sertularella rugosa: part of hydrocaulus with three hydrothecae, ROMIZ B3910. Scale equals 0.5 mm. Also similar to S. polyzonias in the northeastern North Atlantic is Sertularella ellisii (Deshayes & Milne Edwards, 1836), a species differing from S. polyzonias in having three intrathecal cusps within its hydrothecae. These two have recently been shown to be genetically distinct (Moura et al. 2011). Ramil et al. (1992) and Medel & Vervoort (1998) noted that S. ellisii has sometimes been misidentified in European waters as S. ...