Gollum suluensis sp. nov. (Carcharhiniformes: Pseudotriakidae), a new gollumshark from the southern Philippines
Author
Last, Peter R.
Author
Gaudiano, Joe P.
text
Zootaxa
2011
3002
17
30
journal article
10.5281/zenodo.206699
fcbb0e4d-5dba-4caa-9bd4-433f73b6e081
1175-5326
206699
Genus
Gollum
Compagno
Gollum
Compagno, 1973
, Proc. California Acad. Sci., ser. 4, 39(14): 264.
Type
species:
Triakis attenuata
Garrick, 1954
, by original designation.
Definition.
Distinctive carcharhiniform sharks with a firm to soft and very slender body; short, bell-shaped head; long, flattened snout, horizontal length 7–9% TL; small spiracles, 4–10 times in eye length; angular mouth with very small multicuspidate teeth (81–114 rows in jaws); dental bands comb-like near jaw angle; moderately elongate labial furrows (lower furrow subequal to or greater than length of incurrent aperture of nostril); short anterior nasal flaps (subequal to length of excurrent aperture of nostril); broad internarial space, 1.5–1.9 times nostril width; no dermal gill rakers or large oral papillae; first dorsal fin not long-based and keel-like; interdorsal ridge present; first dorsal-fin base well forward of the pelvic-fin base; second dorsal fin taller and more upright than first dorsal fin; anal-fin origin well behind second dorsal-fin origin; free rear tip of anal fin under or slightly forward of second dorsal-fin insertion; no precaudal pits; caudal peduncle relatively elongate, 8–10% TL; dorsal caudal margin short, 19–23% TL, not undulated, instead with a raised scaly ridge; enlarged lateral scales of caudal ridge semicircular, horizontally directed; coloration simple, darker dorsally than ventrally; monospondylous centra 44–53, diplospondylous centra 107–113, total centra 151–166.
Species.
Gollum attenuatus
(
Garrick, 1954
)
,
G. suluensis
sp. nov.
Remarks
. The erection and initial placement of
Gollum
in the family
Proscylliidae
followed
Compagno (1973)
, and was subsequently assigned to a new subgenus Golluminae (
Compagno, 1988
). However, in more recent studies (
Compagno 1999
;
Compagno
et al.
, 2005a
,
2005b
) it has been relocated to the related carcharhiniform family
Pseudotriakidae
.
Gollum
differs from the three proscylliid genera (i.e.
Eridacnis
Smith
,
Proscyllium
Hilgendorf
and
Ctenacis
Compagno
) in having a deep notch on the lateral margin of the snout forward of the nostrils giving the head a bell-shaped appearance (rather more evenly rounded) when viewed dorsolaterally, and lacking gill rakers and oral papillae (
Compagno, 1988
). It shares the family
Pseudotriakidae
with the monotypic genus
Pseudotriakis
Capello
, which differs from
Gollum
in having a soft stocky body (firmer and more slender), a very long, keel-like first dorsal fin (relatively taller and much shorter based), and a much shorter caudal peduncle.