Apristurus microps

Author: (Gilchrist, 1922)

Field Marks:
An Apristurus with an unusually small eye, thick snout, very short interdorsal space, anteriorly projecting mouth, very short pectoral inner margins, and a supracaudal crest of denticles.

Diagnostic Features:
Body relatively stout, especially in subadults, trunk slightly tapering toward head. Snout moderately long, broad, and bellshaped, preoral snout about 9 to 10% of total length; gill slits moderately large, somewhat less than or equal to eye length; gill septa without projecting medial lobes or oleats. Well-incised: eyes very small, especialiy in subadults, less than 3% of total length; nostrils broad, width about 1.2 times in internarial space; incurrent and excurrent apertures very narrow and slitlike, anterior nasal flaps very low; mouth long, large, and broadly arched, with dental bands prominently expanded and with lower ones falling just behind uppers; mouth and labial furrows extending well in front of eyes; labial folds enlarged, but with lower diagonal to body axis. Interdorsal space equal to or slightly less than first dorsal base, one-third to two-fifths of preorbital snout; first dorsal fin about as large or slightly smaller than second, bases about equally long or first slightly shorter than second; origin of first dorsal about opposite last third of pelvic bases; second dorsal insertion behind anal insertion; pectoral fins rather small, anterior margins about 9 to 11% of total length; inner margins extremely short, about a third of pectoral bases; interspace between pectoral and pelvic bases short to moderately long, two-fifths to subequal to prespiracular length and about 6 to 14% of total length; pelvic fins high and broadly rounded; anal fin short, fairly high, and rounded, between three and four times as long as high, its base about equal to prespiracular space and 14 to 16% of total length; caudal fin slender to moderately broad, with a loose crest of enlarged denticles on dorsal caudal margin. Lateral trunk denticles of body with crowns erect and not closely imbricate, skin surface with a feltlike or fuzzy texture. Colour dusky brown or grey-brown to purplish-black, without conspicuous markings on fins. Adults probably large, adolescents to 54 cm.

Geographical Distribution:
Eastern South Atlantic: Southwestern Cape Province, South Africa. ? Eastern Northi Atlantic: between Scotland and Iceland. ? Western North Atlantic: Off Newfoundland.

Habitat and Biology:
A poorly known bottom-dwelling shark of the eastern and western Atlantic continental slopes, on or near the bottom, at depths of 1000 to 2000 m.

Size:
Maximum over 54 cm (adolescent male tentatively referred to this species).

Interest to Fisheries:
None.

Remarks:
The holotype, of unknown size, was apparently discarded (P.C. Heemstra. oers.comm.). Ten specimens in the Institut fur Seefischerei, Hamburg, examined by the writer in 1979 (and labelled as LJVC "Apristurus B") fit this species well in most details, but disagree with Gilchrist's (1922) and Springer's (1979) characterizations in a few particulars, especially in having somewhat longer abdomen and shorter caudal fin, that may be size-related (assuming that the holotype was small). However, they agree with microps in having exceptionally short pectoral inner margins, thick snouts, thick bodies, broadly rounded fins, equal-sized dorsals with the origin of the first over the pelvic bases, unusually short interdorsal spaces, and very small eyes. These specimens are tentatively identified as Apristurus microps here, and were taken off the Cape region of South Africa (2 specimens), the eastern North Atlantic between Iceland and Scotland (4), and on the Newfoundland Bank (4) in the western Atlantic. The largest specimen, a 54 cm adolescent male from the eastern North Atlantic, is illustrated above.

Type material:
Holotype: A specimen of unknown size (but probably small and below 300 mm judging frOom its proOportions), now lost. Type Locality: Eastern South Atlantic west of Cape Town, South Africa, 33 45.8'5, 17 17.1'E, 1445 m depth.

%LABEL% (%SOURCE%)