Pycnogonum is a genus of sea spiders in the family Pycnogonidae. It is the type genus of the family.

Etymology

The generic name literally means “dense knees”. Pycnogonum combines the prefix pycno- (from ‘dense’ in Greek) with the Greek word for "knee": gony (γόνυ).

Characteristics

Members of the genus Pycnogonum have squarish bodies with a tough integument and a few hairs. The cephalon (the anterior end of the body which is fused with the first segment of the trunk) has a long smooth proboscis and a low tubercle on which the eyes are set. There are no chelicerae or palps and these sea spiders use their proboscis to suck juices from their prey. On the first segment of the trunk of males there are small ovigerous legs with nine segments. The larvae are carried around by the males on these appendages. The four pairs of ambulatory legs are short but strong, with well-developed terminal claws. The genital openings are on the second segment of the posterior pair of legs.

Species

The World Register of Marine Species lists the following species:

  • Pycnogonum africanumCalman, 1938
  • Pycnogonum aleuticumTurpaeva, 1994
  • Pycnogonum angulirostrumStock, 1959
  • Pycnogonum anovigerumClark, 1956
  • Pycnogonum arbustumStock, 1966
  • Pycnogonum asiaticumMuller, 1992
  • Pycnogonum aurilineatumFlynn, 1919
  • Pycnogonum benokianumOhshima, 1935
  • Pycnogonum buticulosumHedgpeth, 1949
  • Pycnogonum calculumBamber, 1995
  • Pycnogonum callosumLosina-Losinsky, 1961
  • Pycnogonum carinatumStaples, 2002
  • Pycnogonum cataphractumMobius, 1902
  • Pycnogonum cessaciBouvier, 1911
  • Pycnogonum clarkiStaples, 2002
  • Pycnogonum coninsulumBamber, 2008
  • Pycnogonum cranaobyrsaBamber, 2004
  • Pycnogonum crassirostrumSars, 1888
  • Pycnogonum crosnieriStock, 1991
  • Pycnogonum daguilarensisBamber, 1997
  • Pycnogonum dicerosMarcus, 1940
  • Pycnogonum elephasStock, 1966
  • Pycnogonum eltaninFry & Hedgpeth, 1969
  • Pycnogonum forteFlynn, 1928
  • Pycnogonum gainiBouvier, 1910
  • Pycnogonum gibberumMarcus & du Bois Reymond-M., 1963
  • Pycnogonum gordonaePushkin, 1984
  • Pycnogonum grumusArango, 2003
  • Pycnogonum guyanaeStock, 1975
  • Pycnogonum hancockiSchmitt, 1934
  • Pycnogonum indicumSundara Raj, 1930
  • Pycnogonum kussakiniTurpaeva, 2000
  • Pycnogonum litorale(Strom, 1762)
  • Pycnogonum lobipesStock, 1991
  • Pycnogonum madagascariensisBouvier, 1911
  • Pycnogonum magellanicumHoek, 1898
  • Pycnogonum magnirostrumMobius, 1902
  • Pycnogonum micropsLoman
  • Pycnogonum minutumLosina-Losinsky & Kopaneva, 1973
  • Pycnogonum moniliferumStock, 1991
  • Pycnogonum moolenbeekiStock, 1992
  • Pycnogonum mucronatumLoman, 1908
  • Pycnogonum musaicumStock, 1994
  • Pycnogonum nodulosumDohrn, 1881
  • Pycnogonum occaLoman, 1908
  • Pycnogonum orientale(Dana, 1849)
  • Pycnogonum ornansStock, 1992
  • Pycnogonum panamumHilton, 1942
  • Pycnogonum paragainiMunilla, 1990
  • Pycnogonum planumStock, 1954
  • Pycnogonum platylophumLoman, 1923
  • Pycnogonum plumipesStock, 1960
  • Pycnogonum portusBarnard, 1946
  • Pycnogonum pusillumDohrn, 1881
  • Pycnogonum pustulatumStock, 1994
  • Pycnogonum repentinumTurpaeva, 2003
  • Pycnogonum repentiumTurpaeva, 2003
  • Pycnogonum reticulatumHedgpeth, 1948
  • Pycnogonum rickettsiSchmitt, 1934
  • Pycnogonum saxulumChild, 1998
  • Pycnogonum sivertseniStock, 1955
  • Pycnogonum spatiumTakahashi, Dick & Mawatari, 2007
  • Pycnogonum stearnsiIves, 1883
  • Pycnogonum stylidiumChild, 1995
  • Pycnogonum tenueSlater, 1879
  • Pycnogonum tesselatumStock, 1968
  • Pycnogonum torresiClark, 1963
  • Pycnogonum tuberculatumClark, 1963
  • Pycnogonum tumulosumLoman, 1908
  • Pycnogonum uedaiNakamura & Child, 1983
  • Pycnogonum ungellatumLoman, 1911