Friday, September 6, 2013

[Ichthyology • 2008] Hemiscyllium galei & H. henryi • Two new species of bamboo sharks (Orectolobiformes: Hemiscylliidae) from the Bird’s Head region of western New Guinea (Papua Barat Province, Indonesia)


Hemiscyllium henryi G. R. Allen & Erdmann, 2008

Abstract
Two new species of hemiscylliid sharks are described from the Bird’s Head region of western New Guinea (Papua Barat Province, Indonesia). They differ from congeners on the basis of both colour patterns and DNA composition. Hemiscyllium galei is described from two specimens, 542.5-567.5 mm TL, collected at Cenderawasih Bay. The species is similar in appearance to H. freycineti, reported from areas immediately westward including the Raja Ampat Islands. The new species differs from H. freycineti in possessing white lines and spots along the margin of the large, dark dorsal saddles as well as scattered white spots, mainly on the upper side. In addition, H. galei is characterised by a row of about seven well-defined, horizontally-ovate, dark spots on the lower side between the abdomen and caudal-fin base. Hemiscyllium henryi is described from three specimens, 564.0-815.0 mm TL, collected in the vicinity of Triton Bay. It is most similar in general appearance to H. ocellatum from northern Australia, but differs in the structure of the postcephalic ocellus (usually a pair of merged “twin-ocelli” with a poorly defined white halo) and possesses well-defined dark brown saddles/bars along the back and dorsal margin of the caudal fin as well as a dark spot at the origin of the pectoral and pelvic fins. A final difference concerns the presence of numerous small brown spots on the dorsal fins of H. ocellatum, in contrast to the mainly spotless pattern on the dorsal fins of H. henryi.

Fig. 1. Map of western New Guinea (Papua Barat Province, Indonesia) showing collection locations (star symbols) of new species of Hemiscyllium.
Abbreviations as follows: BH = Bird’s Head Peninsula, CB = Cenderawasih Bay, and RA = Raja Ampat Islands.
NASA satellite images.

 Hemiscyllium galei G. R. Allen & Erdmann, 2008
compared to H. freycineti (lower), reported from areas immediately westward including the Raja Ampat Islands

Holotype: NCIP 6324, male, 567.5 mm TL, reef near Rumberpon Village, western Cenderawasih Bay, Papua Barat Province, Indonesia, 3-4 m, collected by hand, M. and A. Erdmann, 19 February 2007.


Diagnosis: A species of bamboo shark belonging to the genus Hemiscyllium, distinguished by its unique colour pattern, particularly the combination of white lines/spots along the margin of the large, dark saddles on the back, scattered white spots (mainly on upper side), and a row of 7-8 well-defined, horizontally-ovate, dark spots on the lower side between the abdomen and caudal-fin base.

Distribution and habitat: The new species is apparently confined to Cenderawasih Bay, Papua Barat Province, Indonesia. The habitat typically consists of shoreline fringing reefs or shallow patch reefs. The three individuals reported to date have all been encountered at night at depths between 2-4 m. They were usually seen resting on the bottom, but occasionally were observed while slowly swimming or “walking” over the bottom with the pectoral and pelvic fins. Presumably it is sedentary during daylight hours, sheltering under rocky outcrops or tabular corals, which is typical for other family members.

Etymology: The new species is named galei in honour of Jeffrey Gale, an avid underwater photographer, shark enthusiast, and benefactor of the marine realm. Mr. Gale successfully bid to support the conservation of this species at the Blue Auction in Monaco on 20 September 2007 and has given generously to support Conservation International’s Bird’s Head Seascape marine conservation initiative.

Hemiscyllium henryi G. R. Allen & Erdmann, 2008

Holotype: NCIP 6323, male, 783 mm TL, small bay in northwestern portion of Selat Iris, immediately south of Triton Bay, Papua Barat Province, Indonesia, 3-4 m, collected by hand, M. V. Erdmann and M. Allen, 24 April 2006.

Diagnosis: A species of bamboo shark belonging to the genus Hemiscyllium, distinguished by its unique colour pattern, particularly the combination of small scattered spots on the head, body and fins including 13-18 spots on interorbital/dorsal snout region and 6-18 spots on dorsal surface of pectoral fins, and a unique “double-ocellus” marking on middle of side, just behind the head.

Distribution and habitat: The new species is known only from western New Guinea (Papua Barat Province, Indonesia) in the vicinity of Triton Bay in the southern Bird’s Head region. It has been observed/collected both in the bay and at nearby Selat Iris, a narrow channel between the mainland and Aiduma Island. Unlike other parts of the Bird’s Head Peninsula such as Cenderawasih Bay and the Raja Ampat Islands, there is almost no shallow, fringing reef habitat due to the unique geomorphology of the area. Hence, the typical habitat for this shark extends into deeper water (at least 30 m), although it has also been sighted in depths less than 4 m. It is usually seen resting on the bottom, but occasionally is observed while slowly swimming or “walking” over the bottom with the pectoral and pelvic fins. During the day it is generally sedentary, sheltering under rocky outcrops or tabular corals.
Etymology: The species is named H. henryi in honour of Wolcott Henry of Washington D.C., who has generously supported Conservation International’s marine initiatives, including taxonomy of western New Guinea fishes.


Allen & Erdmann. 2008. Two new species of bamboo sharks (Orectolobiformes: Hemiscylliidae) from Western New Guinea. aqua (Miradolo Terme) 13 (3-4): 93–108.

No comments:

Post a Comment