Rynkatorpa Rowe and Pawson, 1967

Pawson, David L. & Vance, Doris J., 2005, Rynkatorpa felderi, new species, from a bathyal hydrocarbon seep in the northern Gulf of Mexico (Echinodermata: Holothuroidea: Apodida), Zootaxa 1050, pp. 15-20 : 16

Genus Rynkatorpa Rowe and Pawson, 1967

Diagnosis: Anchor plates more or less irregular in outline, tending to be rectangular, with small number of perforations (25–50), of which two near center line are usually conspicuously larger than the rest; perforations with smooth to spinous margins. One to three Polian vesicles. (After Rowe and Pawson, 1967).

Type Species: Rynkatorpa hickmani Rowe and Pawson, 1967

Remarks: Rowe and Pawson (1967) listed eight Indo­Pacific species in this genus. Since 1967, three further Indo­Pacific species have been described: R. pawsoni ( Martin, 1969a, 1969b), R. gibbsi ( Rowe, 1977) , and R. coriolisi ( Smirnov, 1997) . Of the 11 species now known in the genus, four, hickmani Rowe & Pawson , bisperforatus (Clark), gibbsi Rowe , and uncinata (Hutton) are essentially shallow­water forms, known from less than 100 meters depth. The other seven species, bicornis (Sluiter), sluiteri (Fisher), timida (Koehler & Vaney), challengeri (Théel) , coriolisi Smirnov , pawsoni Martin , and duodactyla (Clark) are bathyal forms, ranging in depth from 252 to 1,920 meters. It is indeed surprising to find this genus in the Atlantic. Its nearest congeneric neighbors are R. pawsoni and R. duodactyla (Clark) ; both occur off the west coast of North America, and both differ from R. felderi new species in possessing just one pair of terminal tentacle digits.