I got this image of a shark for ID. Place of catch is Andaman, India. The image was labeled with Hemitriakis sp.
I think it could be Mustelus mosis HEMPRICH & EHRENBERG, 1899. Is this correct?
http://shark-references.com/species/view/Mustelus-mosis
Diagnosis after Compagno, 1984: Body fairly slender. Head short, prepectoral length 17 to 22% of total length; snout moderately long and bluntly angular in lateral view, tip rather expanded and bulbous in adults with hypercalcified rostral mass, preoral snout 5.5 to 6.6% of total length, preorbital snout 6.3 to 7.3% of total length; internarial space broad, 2.4 to 2.9% of total length; eyes fairly large, eye length 2.1 to 3 times in preorbital snout and 2.5 to 3.3% of total length; interorbital space 2.4 to 2.9% of total length; mouth moderately long, greater than eye length, its length 2.7 to 3.8% of total length; upper labial furrows about equal to lowers and 1.3 to 2% of total length; teeth molariform and asymmetric, with cusp reduced to a low point, cusplets absent except in very young sharks; buccopharyngeal denticles covering anterior half of palate and mouth floor or entire palate and floor. Interdorsal space 20 to 23% of total length; trailing edges of dorsal fins denticulate, without bare ceratotrichia; first dorsal somewhat falcate, with posterior margin nearly vertical from apex, its midbase closer to pectoral bases than to pelvics; pectoral fins moderate-sized, length of anterior margin 13 to 15% of total length, width of posterior margin 9.8 to 13% of total length; pelvic fins small, anterior margin length 6.5 to 7.9% of total length; anal height 2.9 to 4.7% of total length; anal caudal space greater or subequal to second dorsal height, and 7.1 to 9.1% of total length; ventral caudal lobe more or less falcate in adults. Crowns of lateral trunk denticles lanceolate or tricuspidate, with longitudinal ridges extending their entire length. Rostral node of cranium, hyomandibulae, scapulocoracoid tips; sometimes supraorbital crests and rostral shafts of cranium, extrabranchial cartilages, and radials of second dorsal, pectoral, pelvic, and caudal fin radials hypercalcified in adults; palatoquadrates not subdivided; monospondylous precaudal centra 25 to 39, diplospondylous precaudal centra 34 to 48, precaudal centra 59 to 81. Colour uniform grey or grey-brown, above, light below, no white or dark spots or dark bars; South African examples generally have white-tipped first dorsal and black-tipped second dorsal and caudal. Development viviparous. Size large, adults 63 to 150 cm
Attached are some C. macrostoma images for comparison....
Mustelus mosis certainly seems more likely than a Hemitriakid leopard shark.
Dear Joydeep Pal, many thanks for your opinion. I think Scoliodon sorrakowa is no valid taxa. The valid name is Scoliodon laticaudus (http://shark-references.com/species/view/Scoliodon-laticaudus). I have attached a image of Scoliodon laticaudus. The second dorsal fin at Scoliodon laticaudus is smaller and the anal fin differs from the figured species.
What do you mean?
Jürgen
I agree with the identification as Mustelus mosis Hemprich & Ehrenberg 1899. That species is known to occur at least east to Sri Lanka, but Fish Base shows an image of the species from Lombok, Indonesia, taken by Jack Randall.
It is certainly not Scoliodon laticaudus; the relative sizes of the second dorsal and anal fins are quite different in that species.
Actually, Carcharias sorrahkowah Bleeker 1853 has been treated as a synonym of Rhizoprionodon acutus, but that species also has a smaller second dorsal fin, and a longer anal fin.
Hallo Hr. Fricke, vielen herzlichen Dank für Ihre Einschätzung! Schöne Grüße aus Niederbayern
I also agree that this appears to be Mustelus mosis. However, it's difficult to be absolutely positive given the condition of the specimen. Are there any additional photographs, from other angles?
only other option is one of the Iago complex but dorsal fin not far enough forward
Agreed - it is likely to be a specimen of Mustelus mosis in this area. Although some new species are continuously discovered around the arabian sea. Photographs from different angles, particularly of the head, might help in being more conclusive.
Hello Victoria, hello Will,
I try to geht some more images!
Jürgen
Hallo Jürgen!
What about Mustelus widodoi? I'll be looking forward to see the result of this!
Schöne Grüsse aus USA.
Pancho
Dear Juergen, can you provide more views on differents angles of this specimen particularly head, pectorals fins and position of dorsal fin with anal fins?
Dear Juergen, I have downloaded both images and can not see in detail if the teeth of the lower jaw protrude or not, and if they have high cusps or not. This could discard Mustelus spp. Sensu Compagno (1984), Mustelus mosis have "low-crowned teeth with weak cusps", whereas White and Last (2006) referred that M. widodoi have "Teeth asymmetric between jaws, with a moderately high, rounded cusp, no cusplets; no apparent sexual heterodonty; no toothless spaces at symphysis; exposed evenly around symphysis of lower jaw when mouth closed; not differentiated in each jaw and along jaws". I hope this does not complicate you and help you with identification. Regards Gustavo
It is probably not Mustelus widodoi, as that species is supposed to have a broad silvery margin distally on the first dorsal fin, which is absent in this specimen (here the first dorsal fin is distally dark).
Mustelus mosis is still the most probable identification.
Dear Juergen, I don't think this is either Hemitriakis or Mustelus - the snout is too short, the first dorsal origin is too far behind the pectoral inner corner, the dorsal fins (particularly the first dorsal) are too small and the second dorsal fin is too small relative to the first. The dorsal fin bases also appear to be too short for those genera. From what I can tell from the images it has a well developed anterior nasal flaps, fairly long upper labial furrow, and cuspidate teeth. I also think it may have a precaudal pit which would make it Hemigaleidae. Based on that and its colouration my ID is Chaenogaleus macrostoma.
Dear Juergen,
I agree with Clinton in his appreciation of the photos. To my knowledge, this shark has cuspidate teeth, which does not agree with Mustelus. The drawing of Chaenogaleus macrostoma published by Compagno (1984) in FAO catalogue is equally confusing, since the first dorsal fin is inserted on the inner margin of the pectoral fin, which does not agree with the picture that you show. However, the shark of Mike Harris's photo on FishBase (as long as the specimen is well-identified) is very similar to that of your images, with the insertion of the anterior dorsal fin lagging behind the margin of the pectoral fin. Regards
Gustavo
Hi Clinton, hi Gustavo
I am not sure, because the gill slits of Chaenogaleus macrostoma are large, more than two times eye length, and the second dorsal fin and upper caudal fin lobe are often with distinct black markings. In our case we have small gill slits and only black markings at the second dorsal fin like by Mustelus mosis. I will try to get more images!
Greetings and thanks for your useful discussion! Attached a image of Chaenogaleus macrostoma from the open access JABADO, R.W. & EBERT, D.A. (2015)
Sharks of the Arabian Seas: an identification guide. The International Fund for Animal Welfare, Dubai, UAE. 240 pp.
http://shark-references.com/species/view/Chaenogaleus-macrostoma
Hi Aaron, is it possible to use this images of C. macrostoma at our website? I would be happy to get the permission for the usage!
Dear Juergen,
I just downloaded the photos you attached. It would be great if you could also share photos, if any, of their snout, labial furrows, teeth and the head, trunk and caudal region in order to confirm the species. But just based on surveys I have done I think it is Iago omanensis. Lower labial furrows shorter than the upper ones is one of the main characters I looked for amongst the others. While I was surveying landing sites for elasmos in the North western coast and eastern coast of India, I found this species in abundance. Hope this helps.
Hi Alissa Barnes, I wrote several times to the guy who sent me this two pictures. Until now I got no more images.
All the best
As Will White previously mentioned, the first dorsal is too far back for I. omanensis.
The dorsal and pectoral fins are the wrong shape for Mustelus. I have no suggestions though. I am interested to find the final id.
Hello friends,
just got some new images! It is definitiv no Mustelus mosis! Check the teeth in the upper and lower jaw. In my opinion it must be Hemigaleus australiensis WHITE, LAST & COMPAGNO, 2005! This should be the first record in Indian waters, what is your opinion?
see:
WHITE, W.T. & LAST, P.R. & COMPAGNO, L.J.V. 2005 Description of a new species of weasel shark, Hemigaleus australiensis n. sp. (Carcharhiniformes : Hemigaleidae) from Australian waters. Zootaxa, 1077: 37–49
Attached the two images from
WHITE, W.T. & LAST, P.R. & COMPAGNO, L.J.V. 2005 Description of a new species of weasel shark, Hemigaleus australiensis n. sp. (Carcharhiniformes : Hemigaleidae) from Australian waters. Zootaxa, 1077: 37–49
some close upshot of the shark for your kind reference.
Regards
These new photos make a big difference - definitely not a Mustelus sp! Hemigaleus australiensis certainly looks like a good contender now, although the labial furrows in the Indian specimen look notably longer than in the H. australiensis pic, but this might be due to the condition of the specimen. Of course, it could be a hitherto undescribed Hemigaleus species - it would be very interesting to get its NADH1 sequenced for comparison.
I agree. The tooth morphology is consistent with Hemigaleus and not Chaenogaleus. The snout length, anterior nasal flap morphology and gill size are also a better fit with Hemigaleus than Chaenogaleus. Hemigaleus microstoma is recorded from the general region, although not the Andaman Islands. Compagno (1984) describes H. microstoma as "light grey or bronze colour with no prominent markings other than white or black fin tips and sometimes white spots on sides." This degree of variation is quite unusual. It wouldn't surprise me if H. microstoma turned out to be another species complex. Hemigaleus australiensis was previously reported from Australia as H. microstoma (Last & Stevens 1994).
I agree that the specimen is most likely Hemigaleus australiensis (or an undescribed species), but I will have to take a closer look at the pics when I have time. Please find attached a paper with some information on Hemigaleus microstoma. Cheers, Simon
Dear colleagues. thanks for the interesting discussion.Presently I am away from Andamans and my colleague who is there is taking and sending us the snaps. Due to poor internet connectivity there is a delay in sending the desired photos.Here i am attaching two species, in which, one could be a H. australiensis as suspected and the other one I don't know. Pls comment
The specimen labelled 11A looks like Hemigaleus microstoma to me. I think 4A is best treated as Hemigaleus sp. or Hemigaleus cf. australiensis until you can compare morphology and meristics in detail.
I agree that specimen 11A looks like Hemigaleus microstoma. As can be seen in Figures 3-5 of the paper that I attached to my last answer, the specimen that I examined had a similar coloration of the fin margins and the morphology of the teeth from the upper jaw agrees as well.
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