Colossendeis melancholicus Stock, 1975

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, pp. 79-94 : 90-91

publication ID	https://doi.org/ 10.24199/j.mmv.2007.64.8
persistent identifier	https://treatment.plazi.org/id/D928B222-4E2A-FFEF-8A6D-90FDFEFEFB1C
treatment provided by	Felipe
scientific name	Colossendeis melancholicus Stock, 1975
status

Treatment

Colossendeis melancholicus Stock, 1975 View in CoL

Figures 5A–H View Figure 5 , 7B View Figure 7

Colossendeis melancholicus Stock, 1975: 988–990 View in CoL , figs 11c–f,

12.— Child, 1994:14 [synonymy]

Material examined. Tasmania. NW flank of St Helens Hill , 41°14.7'S, 148°461'E, 1755 m, Benthic dredge. RV Southern Surveyor , CSIRO, 27 Jul 1999, (cruise SS03/99, stn 62) , NMV J48898 View Materials (1 female) .

Diagnosis. A large, glabrous species with a leg span to about 450 mm. Proboscis tubular, extremely long and down-curved, diameter almost uniform throughout the length; 13–14 times as long as wide and close to 3 times length of the trunk. Anterior margin of cephalon with 2 small apophyses. Oviger claw short, strongly curved. Palp segments 3 and 5 of about equal length. two large, unpigmented teardrop-shaped eyes, lateral sensory organs present. Abdomen arched, reaching beyond coxa 1 of leg 4. Tarsal spines irregular in size, several smaller spines interspaced by a single larger spine. Palp segment 10, 6.3–7.4 times as long as median width.

Distribution. Florida Straits, Caribbean region and the Tasman Sea, off Tasmania. 732 m to 1755 m depth.

Type locality. Grand Bahama: (27°57'N, 78°56'W – 27°55'N 78°59'W).

Remarks. The extraordinarily long, down-curved proboscis of this species sets it apart from any other species of Colossendeis . Child’s (1994:14) observation of inconsistencies between Stock’s (1975) figures and his measurements are more general than he noted. Stock’s measurements indicate the proboscis length of the holotype is a little more than twice the trunk length and almost 20 times the maximum width. However, based on his fig. 11d,c, the length of the proboscis is closer to 14 times its maximum width and 3 times the trunk length; the same proportions as found in the Tasman Sea specimen. The main claw of all legs is blunt and the terminal claw of the oviger is much reduced and more strongly curved than figured by Stock (figs 11f, 12e). Oviger segment 6 is longest, gently curved, and a little longer than segment 4. In agreement with the holotype, tiny genital pores are present on the ventral surface of the 2nd coxae of all legs. Propodal sole spines are worn to flat stubs. Faint suture lines separate the trunk segments. The coxal pellicula are pale and have the appearance of a collapsed blister (fig. 7B). This record represents a significant extension in geographic and bathymetric range for this rarely recorded species.