Oestrella

Huys, Rony, 2016, Enigmas from the past: M’Intosh’s (1885) annelidicolous copepods from the voyage of H. M. S. Challenger, Zootaxa 4174 (1), pp. 355-385 : 380-381

Oestrella revisited

M’Intosh (1885) proposed the monotypic genus Oestrella for a new species, O. levinseni (type by original designation), found attached to the deepwater terebellid, Ehlersiella atlantica M’Intosh, 1885 , in the northern Atlantic. The original description was based on a single ovigerous female but the presence of three egg sacs in the vial that contained the incomplete host specimen suggested it was infested by two individuals. M’Intosh (1885) did not discuss the possible relationships of the genus nor did he give any justification for its proposal. Hansen (1892) provisionally included Oestrella in his newly established family Herpyllobiidae but later admitted that it was too inadequately described for classification purposes ( Hansen 1897, 1923). Leigh-Sharpe (1926) excluded the genus from the Herpyllobiidae , a view maintained in Lützen’s (1964) revision of the family but not by Monod & Laubier (1996) who continued to treat Oestrella as a valid genus in the Herpyllobiidae .

Wilson (1932) placed the genus in the suborder Lernaeopodoida, an artificial taxon characterized by the presence of females, which are permanently attached to their hosts, and pygmy males which attach themselves to the females. He was also the first to recognize the close similarity between Oestrella and Melinnacheres and distinguished the genera in his key by the position of the “annulus”, a structure defined as the chitin ring at the base of the neck where it joins the trunk. Boxshall (1977) re-examined the holotype of O. levinseni and relegated Oestrella to synonymy with Melinnacheres , the type and only genus of the family Saccopsidae .