Hansen, 1908
Description
Eye bilobed, the upper lobe is approximately equal in width to the lower lobe; width of upper lobe : width of lower lobe varies from 0.8 to 1.0 [S.maximum eye & rostrum ]. There are no conspicuously enlarged crystalline cones, although facets of the upper lobe are somewhat larger than those of the lower lobe.
Peduncle of first antenna with second and third segments long and slender in female, but short and thicker in male. There are no lobes, lappets or spines on the peduncle of the first antenna that are species-specific in structure. The upper flagellum is shorter than the lower. The peduncle of the flagellum-bearing endopod of the second antenna is extremely elongate, with the penultimate segment reaching beyond the end of the scale (squama). S.maximum lappet lacking ].
Rostrum: the frontal plate is produced into an acute rostrum which reaches about to the anterior limit of the eyes [S.maximum-head-dors-ph ].
Carapace with domed gastric region, with a small median keel [S.maximum-m-drawing ]. There are no lateral denticles.
Thoracic leg 3 elongated and bearing a true chela in which the elongate dactyl segment is distally curved and bears a cluster of small grasping teeth. The dactyl segment is opposed by a slender hook of similar length extending from the propodus [S.maximum thoracic leg S.maximum-chela-ph ].
Abdomen without mid-dorsal keels present. The sixth segment length-height ratio is approximately 2.4. A photophore is present in the first abdominal segment only.
Petasma: the literature reports considerable variability in the shape of the terminal and the proximal process of [S.maximum petasma].
Reproduction: nothing is known about the breeding of this species. The female carries ca. 50 eggs (Mauchline, 1984).
Size
Adults are 20-30 mm.
Larval stages
S.maximum-A
S.maximum-B
S.maximum-C
S.maximum-D
S.maximum-E
Ecology
S. maximum is consumed by fishes.
Depth range
Adults are rarely found above 140 m, and most are caught below 400 m depth.
Distribution in the North Sea
S. maximum does not occur in the North Sea. However, the species is recorded in the northern entrance of the North Sea, originating from the deeper waters of the adjacent NE Atlantic (S. Hay, pers. com.).
World distribution
Widespread in the Pacific, Atlantic and Indian Oceans; in the Pacific it occurs as far north as the Gulf of Alaska and as far south as 63°S. In the northeastern Atlantic it has been reported north off Norway to 70°N.
[After Brinton et al., 1999]