Pycnogonum

Pycnogonum is a genus of sea spiders in the family Pycnogonidae. It is the type genus of the family.[2]

Pycnogonum
Pycnogonum litorale
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Pycnogonida
Order:	Pantopoda
Family:	Pycnogonidae
Genus:	Pycnogonum Brünnich, 1764 [1]
Species
See text

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).[2][3][4]

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.[5]

Species

The World Register of Marine Species lists the following species:[1]

Pycnogonum africanum Calman, 1938 Pycnogonum aleuticum Turpaeva, 1994 Pycnogonum angulirostrum Stock, 1959 Pycnogonum anovigerum Clark, 1956 Pycnogonum arbustum Stock, 1966 Pycnogonum asiaticum Muller, 1992 Pycnogonum aurilineatum Flynn, 1919 Pycnogonum benokianum Ohshima, 1935 Pycnogonum buticulosum Hedgpeth, 1949 Pycnogonum calculum Bamber, 1995 Pycnogonum callosum Losina-Losinsky, 1961 Pycnogonum carinatum Staples, 2002 Pycnogonum cataphractum Mobius, 1902 Pycnogonum cessaci Bouvier, 1911 Pycnogonum clarki Staples, 2002 Pycnogonum coninsulum Bamber, 2008 Pycnogonum cranaobyrsa Bamber, 2004 Pycnogonum crassirostrum Sars, 1888 Pycnogonum crosnieri Stock, 1991 Pycnogonum daguilarensis Bamber, 1997 Pycnogonum diceros Marcus, 1940 Pycnogonum elephas Stock, 1966 Pycnogonum eltanin Fry & Hedgpeth, 1969 Pycnogonum forte Flynn, 1928

Pycnogonum gaini Bouvier, 1910 Pycnogonum gibberum Marcus & du Bois Reymond-M., 1963 Pycnogonum gordonae Pushkin, 1984 Pycnogonum grumus Arango, 2003 Pycnogonum guyanae Stock, 1975 Pycnogonum hancocki Schmitt, 1934 Pycnogonum indicum Sundara Raj, 1930 Pycnogonum kussakini Turpaeva, 2000 Pycnogonum litorale (Strom, 1762) Pycnogonum lobipes Stock, 1991 Pycnogonum madagascariensis Bouvier, 1911 Pycnogonum magellanicum Hoek, 1898 Pycnogonum magnirostrum Mobius, 1902 Pycnogonum microps Loman Pycnogonum minutum Losina-Losinsky & Kopaneva, 1973 Pycnogonum moniliferum Stock, 1991 Pycnogonum moolenbeeki Stock, 1992 Pycnogonum mucronatum Loman, 1908 Pycnogonum musaicum Stock, 1994 Pycnogonum nodulosum Dohrn, 1881 Pycnogonum occa Loman, 1908 Pycnogonum orientale (Dana, 1849) Pycnogonum ornans Stock, 1992 Pycnogonum panamum Hilton, 1942

Pycnogonum paragaini Munilla, 1990 Pycnogonum planum Stock, 1954 Pycnogonum platylophum Loman, 1923 Pycnogonum plumipes Stock, 1960 Pycnogonum portus Barnard, 1946 Pycnogonum pusillum Dohrn, 1881 Pycnogonum pustulatum Stock, 1994 Pycnogonum repentinum Turpaeva, 2003 Pycnogonum repentium Turpaeva, 2003 Pycnogonum reticulatum Hedgpeth, 1948 Pycnogonum rickettsi Schmitt, 1934 Pycnogonum saxulum Child, 1998 Pycnogonum sivertseni Stock, 1955 Pycnogonum spatium Takahashi, Dick & Mawatari, 2007 Pycnogonum stearnsi Ives, 1883 Pycnogonum stylidium Child, 1995 Pycnogonum tenue Slater, 1879 Pycnogonum tesselatum Stock, 1968 Pycnogonum torresi Clark, 1963 Pycnogonum tuberculatum Clark, 1963 Pycnogonum tumulosum Loman, 1908 Pycnogonum uedai Nakamura & Child, 1983 Pycnogonum ungellatum Loman, 1911

References

1. Pycnogonum - Bruennich, 1764 World Register of Marine Species. Retrieved 2011-11-22.
2. "pycnogonid". The Free Dictionary. From New Latin Pycnogonida, class name, from Pycnogonum, type genus: Greek puknos, thick + Greek gonu, knee; see genu- in Indo-European roots.
3. "pycnogonid". Merriam-Webster Dictionary.: "ultimately from Greek pyknos + gony knee"
4. Arnaud, F.; Bamber, R.N. (1 December 1987). "The Biology of Pycnogonida". Advances in Marine Biology. Academic Press. 24: 3. ISBN 978-0-08-057947-4. pycnogonids (meaning "dense-knees")
5. Genus Pycnogonum Marine Species Identification Portal. Retrieved 2011-11-22.