• Contains description
  • Contains photos


USNM 113002.2847

Geographic Distribution

Antarctic Convergence illustration Antarctic convergence

Bathymetric Specimen Dispersal

12 individual specimens found for Cilunculus cactoides.

Cilunculus cactoides Fry & Hedgpeth  Species


Original Description
Inactive node Show the full description

Original Description
Active node Hide the full description

Cilunculus cactoides n. sp. (Figs. 205, 206)


Atka Sta. 23, 1 male, holotype, U.S.N.M. Acq. No. 113006; Burton Island Sta. 3, 1 male, allotype, U.S.N.M. Acq. No. 113002.

Eltanin Sta. 436, 1 female.

DESCRIPTION: -- A small, exceedingly spinose species.

PALP: Comparatively large for the size of the animal, slender and spiny.

TRUNK: Oval in outline, lateral processes narrowly separated, trunk somites distinct; cephalic somite produced forward with spiny anterior cephalic spurs; eye tubercle tall, rounded; eyes conspicuous and well developed; on the three anterior trunk somites there are median tubercles flanked by smaller tubercles with large spines; similar complexes of spiny tubercles at the ends of the lateral processes; abdomen long, with spinose tubercles. There are so many spiny tubercles that it is impossible to decide how many there are, or to measure the specimen accurately.

CHELICERAE: Chelicerae 3-segmented, the terminal segment with a spur-like dactly set in a hollow; large spines on the two scape segments.

OVIGER: Terminal segments with rather large spines, which do not appear to be strongly denticulate.

LEGS: Short, heavily spinose; many of the spines arising from elevated tubercles; large genital prominence on the 2nd coxa of the male, as short, heavy cement gland spigot on the femur at about a third the distance from the distal end; tarsus short, with a few basal spines; propodus with three large basal spines and several smaller ones on the sole; terminal claw approximately two-thirds as long as propodus, curved; accessory claws well developed, about half as long as the terminal claw.


Trunk length

2.3 mm

Proboscis length


Abdomen length


Cephalic somite length


2nd lateral process width


Leg length

Coxa 1


Coxa 2


Coxa 3




Tibia 1


Tibia 2






Main claw


Accessory claw


Total leg length


DISCUSSION: -- This species resembles Cilunculus australiensis Clark, but is more spinose. The dorsal tubercles are lower than the eye tubercle, however, and the cement gland spigot is differently located (in C. australiensis it is at the end of the femur). The ovigeral spines are not strongly denticulate as in Clark’s species.

DISTRIBUTION: -- Specimens have been taken in the Ross Sea and off the South Shetland Islands, at depths of 72-433 m.” (Fry & Hedgpeth 1969, p. 124-126)

Geographic Distribution

Specimens have been taken in the Ross Sea and off the South Shetland Islands, at depths of 72-433 m.


Type Status Catalog No. Date Collected Location Coordinates Depth (m) Vessel
Holotype 113002 Images Available 1/8/1963 Antarctic Ocean 63.2° S , 58.8° W 73 Eltanin R/V
Paratype 152763 1/13/1958 Ross Sea 72.13° S , 172.17° E 433 Burton Island R/V
Allotype 113006 Images Available 1/12/1958 Antarctic Ocean 72.1° S , 172.25° E 421 Atka R/V
  125529 1/25/1963 Antarctic Ocean 64.77° S , 64.1° W 22 – 31 Staten Island R/V
  125530 2/13/1963 Antarctic Ocean 62.54° S , 59.8° W 55 Staten Island R/V
  152765 2/25/1962 South Pacific Ocean 54.55° S , 77.85° W   Vema R/V
  154670 1/10/1968 Ross Sea 72° S , 172.6° E 348 – 352 Eltanin R/V
  154671 1/10/1968 Ross Sea 72.1° S , 172.1° E 523 – 528 Eltanin R/V
  1122806 1/2/1963 Antarctic Ocean 62.6° S , 56.1° W 311 – 426 Eltanin R/V

View additional taxa  View all species collected at same locations as Cilunculus cactoides