Mariansabellaria Kirtley 1994

Genus Mariansabellaria Kirtley, 1994 Type species Phalacrostemma norvegicum Strømgren, 1971; by original designation. Diagnosis Operculum completely divided into two free lobes. Two rows of opercular paleae. Outer paleae arranged in semicircles; straight, cylindrical, or slightly compressed blade wi...

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Bibliographic Details
Main Author: Chávez-López, Yessica
Format: Other/Unknown Material
Language:unknown
Published: Zenodo 2022
Subjects:
Online Access:https://doi.org/10.5281/zenodo.6885898
http://treatment.plazi.org/id/03B2EE18FFFCFFA3265D719CED28006C
Description
Summary:Genus Mariansabellaria Kirtley, 1994 Type species Phalacrostemma norvegicum Strømgren, 1971; by original designation. Diagnosis Operculum completely divided into two free lobes. Two rows of opercular paleae. Outer paleae arranged in semicircles; straight, cylindrical, or slightly compressed blade with transverse irregular thecae bands. Few inner paleae arranged in one short row near to dorsal junction of inner marginal lobes, with straight and cylindrical blades. One or more pairs of nuchal spines. Tentacular filaments arranged in single rows (simple). Palps grooved, longer than operculum. Median ridge short with some lateral eyespots. Median organ absent. Four parathoracic segments (Kirtley 1994; Capa & Hutchings 2019). Remarks Mariansabellaria Kirtley, 1994 included, until now, only four species: M. norvegica (Strømgren, 1971) from the Norwegian Sea, M. chilena Kirtley, 1994 from southern Chile, M. harrisae Kirtley, 1994 from Santa Monica Bay, California, and M. tenhovei Kirtley, 1994 from Yaquina Bay, Oregon. It is necessary to re-describe the species of Mariansabellaria because Kirtley did not include the same characters in all species descriptions. Standardization in the descriptions will facilitate the identification and comparison of the species, and will also allow the development of identification keys with clearer and easier to observe characters. Key to species of Mariansabellaria Kirtley, 1994 1. Inner paleae with smooth margins. M. harrisae Kirtley, 1994. Santa Monica Bay, Los Angeles, California, 183 m depth – Inner paleae with transverse constrictions partially surrounding the blade. 2 2. Middle region of outer paleae with thecae completely surrounding the blade. 3 – Middle region of outer paleae with thecae partially surrounding the blade. 4 3. Thecae of the middle region 5–6 times as wide as long. M. norvegica (Strømgren, 1971). Bindalsfjorden, Norway, 70–400 m depth – Thecae of the middle region almost as long as wide. M. tenhovei Kirtley, 1994. Yaquina Bay, Oregon, 2000 m depth 4. Six ...