Two new species of Sericosura Fry & Hedgpeth, 1969 (Arthropoda: Pycnogonida: Ammotheidae) from a hydrothermal vent on the East Pacific Rise

摘要

Between 17th October and 9th November 2009, the third leg of the Chinese DY115-21 cruise on board the R/V Dayangy-ihao, confirmed two new hydrothermal fields near the equatorial East Pacific Rise. Five pycnogonid specimens were obtained by deep-sea TV-grab from one of the new hydrothermal vents named 'Precious Stone Mountain' at 1.22°N 101.49°W. These specimens belonged to two new species of the obligately-vent-associated pycnogonid genus Sericosura. Three female specimens represent the new speciesSericosura gemmaemonsis with large body size. One male and one female were of the second new species, Sericosura dentatus the male specimen has a mid-dorsal femoral cement-gland-tube, like that of Sericosura dissita, while the female specimen has morefinely-denticulate spines on the oviger strigilis than any other species of the genus.