Micromenia amphiatlantica sp. nov.: First solenogaster (Mollusca, Aplacophora) with an amphi-Atlantic distribution and insight into abyssal solenogaster diversity

• Published in: Deep-sea research. Part I, Oceanographic research papers Vol. 157; p. 103189
• Main Authors: Cobo, M. Carmen, Kocot, Kevin M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2020
• Subjects: Aplacophora; Biodiversity; Deep-sea; Taxonomy; Deep-sea; Biodiversity; Taxonomy; Aplacophora
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/j.dsr.2019.103189

Although many of the most recently described Solenogastres (Mollusca, Aplacophora) come from abyssal locations (3500–6000 m depth), most members of the group have been described from the continental shelf and slope with just 23 of the 290 formally described species known from depths below 3500 m. In addition, most solenogasters are described from one or very few sampling localities, so practically nothing is known about their actual distribution. This lack of information may be attributed to the somewhat labor-intensive nature of the traditional taxonomy of this group, which often results in the exclusion of solenogasters from biodiversity or biogeographic studies. Further, the abyssal basins are one of the most unknown habitats of the planet. Projects such as DIVA (Latitudinal Gradients of Deep-Sea BioDIVersity in the Atlantic Ocean) aim to eliminate such a lack of knowledge about abyssal biodiversity by shedding light on the abundance and distribution of species in this habitat. During the DIVA expeditions (DIVA1: Angola Basin, DIVA 2: Angola, Guinea, and Cape Basin and DIVA·3: Argentina and Brazil Basin), a large number of solenogasters was collected. Here we describe a new species, Micromenia amphiatlantica sp. nov., which occurs in three of the explored basins (Angola, Guinea, and Brazil). This species is characterized by a distinct scleritome, a monoserial radula with paired denticles, and a unique combination of internal anatomical characters. To our knowledge, this is the first described abyssal member of the solenogaster clade Pholidoskepia and the first solenogaster with an amphi-Atlantic distribution. •First records of a solenogaster with an amphi-Atlantic distribution.•First described abyssal member of the solenogaster clade Pholidoskepia.•First described abyssal solenogaster from the Guinea Basin and Brazil Basin.•New insights on abyssal (3500–6000 m) solenogaster diversity.