Deep-Water Crustacea of the Genus Sergestes (Decapoda, Natantia) from Cook Strait, New Zealand
Size
Size
Fig. 10. Sergestes cf. S. seminudus, carapace, lateral view (anterior organ of Pesta represented by broken circle) ♀.
Figs. 11–18. Sergestes potens. Fig. 11—Carapace, lateral view, ♂. Fig. 12—Left scaphocerite, ventral view (setae omitted), ♀ 27 mm. Fig. 13—Left uropod, ventral view (setae omitted), ♀ 27 mm. (Figs. 11–13 drawn to same scale. Photophores represented in black.)
Fig. 15—Right petasma, posterior view, ♂ 24 mm. Fig. 16—as preceding, anterior view.
Fig. 17—Anterior part cephalothorax, lateral view (setae omitted), ♂ 23 mm. Fig. 18—Diagrammatic view ventral surface to show photophore distribution. (Bases of appendages open circles, photophores in black.)
The following measurements were taken from mature specimens of both sexes (mm):
Male. | Female. | |
Length entire | 87.5 | 113 |
Length carapace | 24 | 32 |
Length rostrum | 1.5 | 2 |
Length abdomen | 51 | 66 |
Length 3rd somite abdomen | 9 | 11 |
Length 6th somite abdomen | 12 | 15 |
Length telson | 11 | 13 |
Length 3rd maxilliped | 32.5 | 45 |
Length 1st pereiopod | 24.5 | 34 |
Length 2nd pereiopod | 35 | 48 |
Length 3rd pereiopod | 38.5 | 60 |
Length 4th pereiopod | 28.5 | 37 |
Length 5th pereiopod | 16.5 | 21 |
The male was chosen from the commonest size range (carapace length 24 mm) while the female is the largest specimen in the collection (length entire about 113 mm). This female is, as far as I can ascertain, only surpassed in size by one other specimen of the genus Sergestes recorded in the literature. This is the type male of the closely related S. (Sergia) maximus Burkenroad, 1940, with a length of about 136 mm (carapace length 41.5 mm). The type female of S. (Sergia) inous Faxon, 1893, is also given as 113 mm in length. The length entire is measured from the tip of the rostrum to the posterior tip of the telson and is inaccurate, due to the difficulty in extending the abdomen.