Colossendeis

Colossendeis
	Colossendeis macerrima from Atlantic Ocean. Museum specimen
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Pycnogonida
Order:	Pantopoda
Family:	Colossendeidae
Genus:	Colossendeis; Jarzinsky, 1870

Colossendeis is a genus of sea spider (class Pycnogonida) belonging to the family Colossendeidae.^[1] These sea spiders are typically found in the deep sea. This genus includes the largest pycnogonids, with leg spans frequently ranging from 40 to 50 cm (16-20 in).^[2] The largest sea spider, Colossendeis colossea, can reach a leg span of 70 cm (28 in).^[3] This genus also includes some bioluminescent sea spiders.^[4]

Description

Sea spiders in this genus feature an unsegmented trunk, a low ocular tubercle, and a well-developed abdomen. Chelifores are absent in adults. The palps and ovigers touch at their bases, and the strigilis is tightly curved with a strong terminal claw. Species in this genus have only four pairs of legs. The ventral surface of the second most proximal article (second coxa) of some or all of these legs features tiny genital pores.^[2]

Feeding

Sea spiders in this genus feed on cnidarians, sponges, bryozoans, small mollusks, and small polychaetes.^[5]

Phylogeny

Although all species in this genus are eight-legged, phylogenetic analysis based on molecular data indicates that this genus is paraphyletic with respect to the ten-legged genus Decolopoda and the twelve-legged genus Dodecolopoda; these two polymerous (extra-legged) genera are nested within the genus Colossendeis in a phylogenetic tree.^[6]^[7]^[8] This paraphyly would normally make both Dodecolopoda and Colossendeis junior synonyms of Decolopoda, the oldest name, and require all three genera to merge under the name Decolopoda. To avoid this disruption, authorities keep these genera under different names and retain Colossendeis as a paraphyletic genus.^[6]

The molecular evidence also indicates that both Decolopoda and Dodecolopoda are nested within a monophyletic group containing the "longitarsal" species in the genus Colossendeis. The sea spiders in this "longitarsal" clade feature legs in which the three most distal articles (claw, propodus, and tarsus) taken together are at least three-quarters the length of the fourth most distal article (second tibia). This clade includes not only Antarctic species of Colossendeis such as C. australis and C. glacialis but also widespread taxa such as C. megalonyx and C. robusta. In "brevitarsal" species, such as C. macerrima, the three most distal articles are instead much shorter relative to the second tibia.^[6]

Species

There are 72 species:^[1]

Colossendeis acuta Stiboy-Risch, 1993
Colossendeis adelpha Child, 1998
Colossendeis angusta Sars, 1877
Colossendeis aperta Turpaeva, 2005
Colossendeis arcanus Turpaeva, 2008
Colossendeis arcuata A. Milne-Edwards, 1885
Colossendeis australis Hodgson, 1907
Colossendeis avidus Pushkin, 1970
Colossendeis belekurovi Pushkin, 1993
Colossendeis bicincta Schimkewitsch, 1893
Colossendeis bouvetensis Dietz, Pieper, Seefeldt & Leese, 2015
Colossendeis brevirostris Child, 1995
Colossendeis bruuni Fage, 1956
Colossendeis clavata Meinert, 1899
Colossendeis colossea Wilson, 1881
Colossendeis concedis Child, 1995
Colossendeis cucurbita Cole, 1909
Colossendeis curtirostris Stock, 1963
Colossendeis dalli Child, 1995
Colossendeis drakei Calman, 1915
Colossendeis elephantis Child, 1995
Colossendeis enigmatica Turpaeva, 1974
Colossendeis ensifer Child, 1995
Colossendeis fijigrypos Bamber, 2004
Colossendeis fragilis Pushkin, 1993
Colossendeis gardineri Carpenter, 1907
Colossendeis geoffroyi Mane-Garzon, 1944
Colossendeis glacialis Hodgson, 1907
Colossendeis gracilis Hoek, 1881
Colossendeis grassus Pushkin, 1993
Colossendeis hoeki Gordon, 1944
Colossendeis insolitus Pushkin, 1993
Colossendeis korotkevitschi Pushkin, 1984
Colossendeis kurtchatovi Turpaeva, 1993
Colossendeis leniensis Pushkin, 1993
Colossendeis leptorhynchus Hoek, 1881
Colossendeis longirostris Gordon, 1938
Colossendeis losinskii Turpaeva, 2002
Colossendeis macerrima Wilson, 1881
Colossendeis media Hoek, 1881
Colossendeis megalonyx Hoek, 1881
Colossendeis melancholicus Stock, 1975
Colossendeis mica Pushkin, 1970
Colossendeis microsetosa Hilton, 1943
Colossendeis minor Schimkewitsch, 1893
Colossendeis minuta Hoek, 1881
Colossendeis mycterismos Bamber, 2004
Colossendeis nasuta Hedgpeth, 1949
Colossendeis notialis Child, 1995
Colossendeis oculifera Stock, 1963
Colossendeis peloria Child, 1994
Colossendeis perforata Turpaeva, 1993
Colossendeis pipetta Stock, 1991
Colossendeis potentis Turpaeva, 2008
Colossendeis proboscidea (Sabine, 1824)
Colossendeis pseudochelata Pushkin, 1993
Colossendeis robusta Hoek, 1881
Colossendeis rostrata Turpaeva, 1994
Colossendeis scoresbii Gordon, 1932
Colossendeis scotti Calman, 1915
Colossendeis sinuosa Stock, 1997
Colossendeis spicula Child, 1994
Colossendeis stramenti Fry & Hedgpeth, 1969
Colossendeis subminuta Schimkewitsch, 1893
Colossendeis tasmanica Staples, 2007
Colossendeis tenera Hilton, 1943
Colossendeis tenuipedis Pushkin, 1993
Colossendeis tethya Turpaeva, 1974
Colossendeis tortipalpis Gordon, 1932
Colossendeis vityazi Turpaeva, 1973
Colossendeis weddellensis Turpaeva, 2008
Colossendeis wilsoni Calman, 1915

References

^ ^a ^b Bamber RN, El Nagar A, Arango C, eds. (2023). "Colossendeis Jarzynsky, 1870". Pycnobase: World Pycnogonida Database. World Register of Marine Species. Retrieved 18 August 2023.
^ ^a ^b Staples, David A. (2007). "A new species of Colossendeis (Pycnogonida: Colossendeidae) together with records from Australian and New Zealand waters". Memoirs of Museum Victoria. 64: 79–94. doi:10.24199/j.mmv.2007.64.8.
^ Gardner, C.E.; Bain, B.A.; Govedich, F.R. (2016). "Revision of Colossendeis colossea Wilson, 1881 (Pycnogonida Family Colossendeidae)". The Society for Integrative and Comparative Biology. Retrieved 2024-08-04.
^ Herring, Peter J. (1987). "Systematic distribution of bioluminescence in living organisms". Journal of Bioluminescence and Chemiluminescence. 1 (3): 147–163. doi:10.1002/bio.1170010303. PMID 3503524.
^ Dietz, Lars; Pieper, Sven; Seefeldt, Meike; Leese, Florian (2015-04-17). "Morphological and genetic data clarify the taxonomic status of Colossendeis robusta and C. glacialis (Pycnogonida) and reveal overlooked diversity". Arthropod Systematics & Phylogeny. 73: 107–128. doi:10.3897/asp.73.e31820. ISSN 1864-8312.
^ ^a ^b ^c Dietz, Lars; Dömel, Jana S.; Leese, Florian; Mahon, Andrew R.; Mayer, Christoph (2019-07-01). "Phylogenomics of the longitarsal Colossendeidae: The evolutionary history of an Antarctic sea spider radiation". Molecular Phylogenetics and Evolution. 136: 206–214. Bibcode:2019MolPE.136..206D. doi:10.1016/j.ympev.2019.04.017. ISSN 1055-7903. PMID 31002869.
^ Krabbe, Kathrin; Leese, Florian; Mayer, Christoph; Tollrian, Ralph; Held, Christoph (2010). "Cryptic mitochondrial lineages in the widespread pycnogonid Colossendeis megalonyx Hoek, 1881 from Antarctic and Subantarctic waters". Polar Biology. 33 (3): 281–292. doi:10.1007/s00300-009-0703-5. ISSN 0722-4060.
^ Ballesteros, Jesús A; Setton, Emily V W; Santibáñez-López, Carlos E; Arango, Claudia P; Brenneis, Georg; Brix, Saskia; Corbett, Kevin F; Cano-Sánchez, Esperanza; Dandouch, Merai; Dilly, Geoffrey F; Eleaume, Marc P; Gainett, Guilherme; Gallut, Cyril; McAtee, Sean; McIntyre, Lauren (2021-01-23). Crandall, Keith (ed.). "Phylogenomic Resolution of Sea Spider Diversification through Integration of Multiple Data Classes". Molecular Biology and Evolution. 38 (2): 686–701. doi:10.1093/molbev/msaa228. ISSN 1537-1719. PMC 7826184. PMID 32915961.