Cystisoma longipes Bovallius, 1886
- Dataset
- Pelagic Invertebrates
- Rank
- SPECIES
Classification
- class
- Crustacea
- order
- Amphipoda
- family
- Cystisomatidae
- genus
- Cystisoma
- species
- Cystisoma longipes
general
Type Locality:
Off the west coast of Australia, 30°S, 90°E. [Zeidler, 2003] .biology
Notes:
Similar to C. magna in that mature specimens have relatively short first antennae. These two species may have been identified with C. latipes on the basis of antennal length but the shape of the head and pereopod articles are characteristic of Cystisoma longipes. [Zeidler, 2003] .diagnostic
The head in females is spherical. Marginal denticles are numerous, more so than in other species: 15-18, more often 16-17. The number of marginal denticles on the left and right, as in other species, is sometimes not equal. There are five-six pairs of ventral denticles; the anterior denticles are very large, glandular, almost not differentiated from the denticles of the arcuate rows. The mandibles bear two denticles; the large central one is acute and slightly curved medially and the lateral denticle, though similar to the central, is smaller and placed about midway between the central denticle and the place of attachment of the mandible; a third denticle sometimes occurs on te outer side (either as a tubercle as shown by Stephensen or as a developed denticle, as in the specimen in our collection). Pereopods I-II have well-developed basal spines although these are shorter than in C. pellucide. The 2nd segment of pereopods I is longer than the rest of the leg and bears denticles on its anterior margin and in the distal part of its posterior margin; the 4th segment is asymmetrical, with a shortened anterior margin and an angular lobe posteriorly armed with setae; the 5th segment is elongated, the process coarsely denticulate and extends to the base of the claw; the 6th segment is anteriorly convex, has two denticulate keels that project with acute denticles along the sides of the claw, and is twice longer than wide; the claw is half the length of the 6th segment. The 2nd segment of pereopods II is longer than the rest of the leg and armed as in pair I; the denticulate process of the 5th segment is longer than its basal part and extends beyond the base of the claw; the 6th segment is four times longer than wide, more coarsely denticulate posteriorly and anteriorly, and weakly curved; the claw is half the length of the 6th segment. The 2nd segment of pereopods III is narrow and longer than the 3rd-5th segments together; the 4th segment is shorter than the 5th, the 6th segment equal to it but narrower; all the distal segments are denticulate on the posterior side but the 5th-6th segments have transverse rows of setae on the surface. In pereopods IV the segments are approximately of the same proportions but longer. Pereopods V-VI are very long, pair V almost as long as the animal itself and pair VI shorter by the length of the last segment. The 2nd segment of pereopods V has denticulate carinate margins, is six-seven times longer than wide, and the anterior margin distally has a denticulate lobe overhanging the base of the 3rd segment; the total length of the 4th-5th segments is notably more than the length of the 2nd; the 4th segment is shorter than the 5th and both have denticulate anterior margins; the 6th segment is narrow, equal to or slightly longer than the 5th segment. Pereopods VI are similar to pereopods V but all the segments are relatively shorter. Pereopods VII are short, not extending beyond the end of the 4th segment of pair VI. Unfortunately, the structure of the "egg forceps" of the mature female was not described because Bovallius worked with a young female (which he mistook for a male). According to the description of C. africanum given by Barnard, the "egg forceps" is similar to that in C. pellucide: the notch of the distal margin of the 6th segment is not deep and the deeply curved claw touches the apex of the process of the anterior margin; the segment itself is distally broadened. [Bovallius, 1886].
distribution
The Atlantic Ocean from 57° N to 33° S, tropical region of the Indian Ocean, south-eastern and equatorial parts of the Pacific Ocean (30° S, 165° E; 7° 40' N 150° W). [Bovallius, 1886].
look_alikes
Bovallius, 1886: 13-16 (Thaumatops); 1889: 47 (Thaumatops spec. A, non B); Stebbing, 1888: 1327. --bovalli Woltereck, 1903: 457 (Thaumatops); Stephensen, 1918: 59 (Thaumatops). --africanum Banard, 1916: 287. --magna (non Woltereck, 1903); Shoemaker, 1945a: 233.
size
Length of females up to 80 mm; males are smaller. [Bovallius, 1886].
Name
- Homonyms
- Cystisoma longipes Bovallius, 1886