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Shark of the week: Indian swellshark — 16. July 2018

Shark of the week: Indian swellshark

Another swellshark of the family Catsharks (Scyliorhinidae), the Indian swellshark (Cephaloscyllium silasi) lives in the western Indian Ocean from Quilon, India to Sauqira Bay, Oman.

Cephaloscyllium silasi quilon.jpg
By K.V. Akhilesh – http://www.fishbase.us/photos/thumbnailssummary.php?ID=800#, CC BY 3.0, Link

This small shark is only up to 17 in – 45 cm – long and oviparous (the female lays egg cases).

Sources: herehere and here

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shark of the week: Balloon shark — 9. July 2018

shark of the week: Balloon shark

After a genus native solely around Indonesia and Australia, sharks of this genus populate many areas of the Pacific and Indian Ocean. The genus swellsharks of the family catsharks (Scyliorhinidae) is named after their ability to inflate their belly to about double or triple its regular size like pufferfish do, as described here. Almost all of their names reflect that, for instance todays Balloon shark (Cephaloscyllium sufflans). This species lives solely off southern Mozambique and KwaZulu-Natal, South Africa.

Cephaloscyllium sufflans distmap.png
By Chris_huh – Compagno, Leonard; Dando, Marc & Fowler, Sarah (2005). Sharks of the World. Collins Field Guides. ISBN 0-00-713610-2., CC BY-SA 3.0, Link

As bottom dwelling sharks Balloon sharks live over sandy and muddy flats on the continental shelf and uppermost slope at depths between 130 and 1,970 ft – 40 and 600 m. Juveniles of this species are often encountered as bycatch of bottom trawling fisheries and are discarded. Nevertheless, the IUCN considered this species as Least Concern, as it seems that adult sharks inhabit deeper regions and also lay their egg cases there (they are oviparous), so for now the population is healthy.

Sources: here, here and here

Shark of the week: Papuan epaulette shark — 2. July 2018

Shark of the week: Papuan epaulette shark

The last species from the genus Epaulette sharks or Hemiscyllium is the Papuan epaulette shark (Hemiscyllium hallstromi). The whole genus is a great example for plate tectonics and evolution, as shown in this great paper by Gerald Allen et. al.

comparisation of all nine hemiscyllium species
comparisation of all nine hemiscyllium species: A) H. freycineti, B) H. hallstromi, C) H. galei, D) H. trispeculare, E) H. ocellatum, F) H. michaeli, G) H. halmahera, H) H. henryi & I) H. strahani Credit: Allen et al 2016

The little (up to 30 in -77 cm- length ) Papuan epaulette shark (B in the picture) has a limited habitat in shallow tropical waters on seagrass beds and occasional rocks and coral reefs near Port Moresby, the capital of Papua New Guinea. It is considered vulnerable by the IUCN due to overfishing (mostly as bycatch) by industrial and artisanal fisheries in destructive practices like trawling and dynamite fishing, pollution by river-borne pollutants, sewerage effluent from Port Moresby and sedimentation from mining run-off, and habitat destruction by oil exploration and pipeline development.

Sources: here and here

Shark of the week: Speckled carpetshark — 25. June 2018

Shark of the week: Speckled carpetshark

One of the few Epaulette sharks (Hemiscyllium) not living solely off Indonesia is the Speckled carpetshark (Hemiscyllium trispeculare). Discovered a few years after its sister species, the Indonesian speckled carpetshark, this species can be found off northern Australia and possibly off Indonesia, too.

Like all sharks of the family bamboo sharks (longtail carpet sharks or Hemiscylliidae), this species is oviparous, that means females lay egg cases. Due to large marine protected areas, the habitat of this little (up to 31 in -79 cm- long) reef shark is mostly secure, thus the Speckled Carpetshark is considered of least concern by the IUCN.

Sources: here, here and here

Shark of the week: Hooded carpetshark — 18. June 2018

Shark of the week: Hooded carpetshark

Another shark from the family bamboo shark (or longtail carpet sharks, Hemiscylliidae) living in coral reefs off Papua New Guinea (only a small region off the northern and southern coasts from the eastern part) is the Hooded carpetshark (Hemiscyllium strahani). Like all the other epaulette sharks (Hemiscyllium), its distinct features are different markings, this time large white spots and small dark spots, and an unique black mask over the head and snout (like an ‘executioner’s hood’, thus its name).

Hooded carpetshark, © Randall, John E., found on fishbase.org

This up to 31.5 in -80 cm- long walking shark is in danger due to destruction of its rather small habitat by pollution or dynamite fishing, but may be exploited in the  aquarium trade. The IUCN considers this species as vulnerable.

Sources: here, here and here

Shark of thee week: Indonesian speckled carpetshark — 11. June 2018

Shark of thee week: Indonesian speckled carpetshark

After the Epaulette shark from 1788, the next new species of the genus Hemiscyllium has been described in 1824. The Indonesian speckled carpetshark (Hemiscyllium freycineti) is another walking shark from around Indonesia and seems to live solely off western New Guinea, whereas the newly discovered Milne Bay Epaulette shark assumed the eastside (and many of the pictures). Despite being common for so long, not much is known about this reef shark of the family Longtail carpet sharks (or bamboo sharks, Hemiscylliidae), not even its length.

Hemiscyllium freycineti, Adult from reeflifesurvey.com
adult Hemiscyllium freycineti, © reeflifesurvey.com

Like all Epaulette sharks, the Indonesian speckled carpetsharks is oviparous (that means the female lays egg cases). This cute little shark is often caught for aquarium trade. Due to habitat destruction and destructive or illegal fishing practices, but above all, its newly discovered restricted distribution, it may very well be considered Vulnerable instead of only Near Threatened in the near future.

Sources: here, here and here

Shark of the week: Triton epaulette shark — 4. June 2018

Shark of the week: Triton epaulette shark

The other epaulette shark whose scientific name was auctioned off in the “Blue Auction” by Gerald R. Allen (just like the Hemiscyllium galei – Cenderwasih epaulette shark introduced two weeks ago), was named after Wolcott Henry, another famous underwater photographer (for instance for books and National Geographic): the Triton epaulette shark or Henry’s epaulette shark (Hemiscyllium henryi). Found off Triton Bay on the southern coast of West Papua, this shark of the family longtail carpet sharks (or bamboo sharks, Hemiscylliidae) reaches a length of 32.1 in – 81.5 cm – and it’s unique markings contain numerous fine black spots with a pair of double spots on the sides.

Hemiscyllium henryi
Hemiscyllium henryi from Triton Bay, West Papua. Photo by M. Erdmann

It is no coincidence that this new shark species had been found off Papua New Guinea, too, but that’s not only due to Gerald R. Allen’s work there.  The area around the Raja Ampat Islands, for instance, is said to contain the richest marine biodiversity on earth, especially coral reef related (75% of all coral species worldwide can be found here). But this “Crown Jewel of the Bird’s Head Seascape” is in danger. Not only occurred there a Cruise ship incident in 2017, causing the destruction of 1,600 square meters of coral reef, but habitat degradation due to mining and logging and destructive fishing practices like dynamite or cyanide fishing are reasons, too. A chain of recently established or planned marine protected areas strives to protect this underwater paradise. Initiatives to raise awareness and educate both local and international communities on climate change and sustainable tourism, jobs and fishing, and funding jobs for locals in reef protection and restoration go a long way to bring local communities in and hopefully stop planned palm oil plantations.

Thank you, Wolcott Henry, for funding this efforts!

Sources: herehere and here

Hai der Woche: Hemiscyllium halmahera — 28. May 2018

Hai der Woche: Hemiscyllium halmahera

Der (bis jetzt) letzte entdeckte laufende Hai ist der Hemiscyllium halmahera, benannt nach der Indonesischen Insel Halmanera, in deren Nähe er gefunden wurde.

Diese im Jahr 2013 eingeführte Art der Familie Hemiscylliidae (Bambushaie oder Lippenhaie) ist bis zu 70 cm lang und am ähnlichsten zu ihrer Schwesternart von letzter Woche, dem Cenderawasih-Epaulettenhai, aber mit erheblich anderen Markierungen und Färbung.

Quellen: hier und hier

shark of the week: hemiscyllium halmahera —

shark of the week: hemiscyllium halmahera

The (till now) last discovered walking shark is the hemiscyllium halmahera, named after the Indonesian island Halmanera near which it had been found.

This in 2013 introduced species of the family Hemiscylliidae (bamboo sharks or longtail carpet sharks) is up to 28 in -70 cm- long and is most similar to its sister species from last week, the Cenderawasih epaulette shark, but with vastly different markings and coloring.

Sources: here and here

Shark of the week: Cenderwasih epaulette shark — 21. May 2018

Shark of the week: Cenderwasih epaulette shark

Another shark of the family Hemiscylliidae (also called longtail carpet sharks or bamboo sharks) recently found is the Cenderwasih epaulette shark, named after the small bay in western Papua New Guinea where this cute litte shark (up to 22.4 in -56.8 cm-) lives in reefs at depths of 6 ft 7 in to 13 ft 1 in -2 to 4 m. It is of the same genus like last week’s shark (Epaulette sharks or Hemiscyllium), looks a lot like it too (but mit different markings), is also a walking shark and was in 2008 also named by Gerald Allen.

Hemiscyllium galei from Cenderawasih Bay, West Papua. (C) G. Allen

But the Hemiscyllium galei wasn’t named after its discoverer, or to honor a colleague or former scientist, but the scientific name was auctioned of at a “Blue Auction”. That is not common, but it succeeded to raise enough money to protect the Raja Ampat Islands, after all, which are now part of a marine reserve. So, thank you, Jeffrey Gale, according to fishbase.de “an avid underwater photographer, shark enthusiast, and benefactor of the marine realm” whose films can be found, for instance, here, and photographs here (and I could link his own picture, too, the internet is fascinating and frightening, isn’t it?).

Sources: herehere and here