Two new species of benthopelagic Stephos (Copepoda, Calanoida, Stephidae) from Korea

Abstract

Two new species of benthopelagic copepods of the genus Stephos T. Scott, 1892, belonging to the family Stephidae G.O. Sars, 1902, are described based on specimens collected in the stagnant water flooding the burrows excavated by ocypodid crabs in two intertidal mud-flats, and from near-bottom shallow waters in Korea, respectively. They can be easily diagnosed based on the ornamentation of both the female genital double-somite and genital operculum; the morphology of the distal segment of the male right P5; the presence/absence of a tiny pointed process on the distomedial angle of second segment of female P5; and the condition (seta or spine) of the lateral armature element on the distal segment of female fifth legs, among other features. This is one of the few cases reported of calanoid copepods living as commensals of other invertebrates, and raises to six the number of members of the genus reported from Asia. This is also the first record of the family Stephidae in Korea.

A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae)

“…4J) vs. seven long plus 13 short lamellae, and right leg with distal segment bifurcate, with both branches subequally long (Fig. 3B) vs. outer branch extremely long, inner branch reduced (Moon et al 2015, fig. 4d).…”

“…The new species S. fernandoi can be assigned to “group IV” by its possession of a male right leg 5 with a narrow fourth segment. Currently, this group includes nine species: S. pentacanthos Chen & Zhang, 1965 from off China, S. tsuyazakiensis Tanaka, 1966 from Japan, S. rustadi Strömgren, 1969 from Norway, S. morii Greenwood, 1977 from Australia, S. pacificus Ohtsuka & Hiromi, 1987 from Japan, S. angulatus Bradford-Grieve, 1999 from New Zealand, S. marsalensis Costanzo, Campolmi & Zagami, 2000 from Italy, S. vivesi Jaume, Boxshall & Gràcia, 2008 from the Balearic Islands, and S. goejinensis Moon, Yeon & Venmathi Maran, 2015 from Korea (see table 1 in Bradford-Grieve 1999; Jaume et al 2008; Moon et al 2015). …”

“…Stephids are in general benthopelagic or anchialine forms, strongly associated with the bottom communities, but some species are known from the plankton (Fleminger 1957; Kos 1972; Ohtsuka and Hiromi 1987; Costanzo et al 2000; Zagami et al 2000; Moon et al 2015). Except for the planktonic S. deichmannae , all the stephids found in the NWTA are cave-dwelling anchialine forms (Fosshagen 1970; Bowman 1976; Yeatman 1980).…”

“…The latter family contains marine hyperbenthic forms living in coastal waters and in anchialine habitats. It contains 4 valid genera of which Stephos T. Scott, 1892 is the most diverse, currently incorporating 31 species (Bradford-Grieve 1999; Boxshall and Halsey 2004; Moon et al 2015; Boxshall and Walter 2016). Members of this genus have been reported from tropical to polar latitudes worldwide; Stephos has been recognized to frequently inhabit submarine and anchialine caves (Jaume et al 2008; Kršinić 2012, 2015).…”

Three new species of the genus Stephos Scott, 1892 (Crustacea, Copepoda, Calanoida, Stephidae) from Jeju Island, Korea

“…Stephos Scott, 1892;Parastephos Sars, 1902;Miostephos Bowman, 1976 andParastephos Sars, 1902;Speleohvarella Kršinić, 2005. Their species are generally smaller in body size, and include hyperbenthic forms living in anchialine and marine coastal habitats (Boxshall and Halsey 2004;Jaume et al 2008;Kršinic 2012Kršinic , 2015Moon et al 2015;Suárez-Morales et al 2017). The genus Stephos is the most diverse, comprising 32 species (Bradford-Grieve 1999; Boxshall and Halsey 2004;Kršinić 2015;Moon et al 2015;Suárez-Morales et al 2017). Up to now, there have been a total of eleven species from the Australia-Western Pacific region, as follows: S. pentacanthos Chen & Zhang, 1965;S.…”