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Fish round up: the nudibranch that borrowed chlorophyl from its food

par Ksso le 18 mai 2012

Wired had a cool piece one one of the divers's biggest crush : nudibranchs. If you're a diver, and even more if you're an (wannabe) underwater macro photographer - you know how beautiful and photogenic those babies can be. But it's not the colors or shape that we'll be interested on with Elysia chlorotica, but how it's using some genes and photosynthesizing organelles from the algae it's feeding on. As wired reports, Now it turns out that the slug has acquired enough stolen goods to make an entire plant chemical-making pathway work inside an animal body, says Sidney K. Pierce of the University of South Florida in Tampa“This could be a fusion of a plant and an animal — that’s just cool,”...

Fish round-up : the Butterflyfish

par Ksso le 28 septembre 2011

I love Butterflyfish, they usually come in pairs and are kind enough to swim into the bule letting you take cool shots at them. Butterflyfish are part of the Chaetodontidae family which counts about 10 genera and 114 species. As described by the University of Michigan,members of this family vary considerably in terms of color, but all butterflyfishes share certain morphological traits such as a deep, laterally compressed body, ctenoid scales that extend onto the soft-rayed portions of the dorsal and anal fins, and jaws that may be slightly or extremely elongated. They can measure up to 30cm although the typical butterflyfish is more around 20cm and usually can be seen around 15-30m...

Fish round-up: Meet the boss : the Triggerfish

par Ksso le 20 septembre 2011

Triggerfishes are members of the Balistidae family which accounts for about 40 species. The Triggerfish is a fairly common species that can be found all over the oceans in tropical and sub-tropical waters (I recently saw a bunch in Thailand). The indo-pacific ocean offers the most diverse set of species.Divers know the triggerfishes well, especially if you've been diving during their nesting seasons since they get really aggressive. I heard numerous reports of divers being chased by them for a long time (and enven during deco stops which can be a hassle) - in those circumstances do not hesitate to kick the triggerfish with your fins.The Triggerfish has a small but strong- jawed mouth...

Fish round-up : the Humpback Whale

par Ksso le 25 août 2011

When it comes to whale-watching, the Humpback whale likes to be the star. This gigantic animal, around 12 to 16m long, is friendly and curious about object entering its environments and can often come for minute drolling around a boat full of excited whale-watchers. The Humpback is totally harmless to humans, set aside its huge raw force (being hit by a whale finn must hurt...). It feeds exclusively on krill and small fish. The species is pretty well scattered around the oceans with about 80 000 specimens migrating up to 25 000 km yearly from the cold northern waters in summer down to tropical waters.It's easy to recognize with unusually long pectoral fins and a knobby head. Since it's...

Sci-fi Nudibranchs

par Ksso le 26 juillet 2011

I just got my attention drawn towards those two amazing nudibranchs... that just look like aliens from a Dragon Ball anime. (there's something of Frazer in them isn't it ? ). These Glaucus atlanticus (left) and Glaucilla marginata were washed up on Surfers Paradise Beach in Queensland Australia in 2007. The larger one is about 35 mm in length.The normal size of Glaucus atlanticus is between 5 and 8 cm in length. The maximum recorded length is 40 cm. It floats upside down on the surface tension of the ocean. G. atlanticus preys on other larger pelagic organisms: the dangerously venomous Portuguese Man o' War Physalia physalis; the by-the-wind-sailor Velella velella; the blue button Porpita...

Fish round-up: the Lionfish

par Ksso le 13 juin 2011

Lionfish (Pterois) are beautful - and dangerous. Originating from the Indo-Pacific Ocean, they have been introduced by mistake in the Atlantic in mid-90s and have become invasive along the East Coast of the US. Lionfishes measure 6.2 to 42.4 cm with typical adults measuring 38 cm and weighing an average of 480 g.While beautiful, his tentacles ar poisonous making it a hazard to fishermen and divers. Pterois venom produced negative inotropic and chronotropic effects when tested in both frog and clam hearts and has a depressing effect on rabbit blood pressure. These results are thought to be due to nitric oxide release. In humans, Pterois venom can cause systemic effects such as vomiting,...

Fish round-up: Flying Gurnard

par Ksso le 28 mai 2011

Flying gurnards are fast and sneaky. They camouflage on sandy bottom and the moment they feel they have been spotted they race their way away from you. I remember chasing one in Indonesia, Lombok at Meno Wall, and only managed to snap blurry pics after a few minutes of intense race.The Flying gurnards (Dactylopteridae) are fairly widespread as the GBIF map shows, yet they are fairly tough to spot usually (although apparently you now get a lot of those in Malta. They like to stay pretty deep (the oriental flying gurnard usually inhabits sandy bottoms at around 100m/330ft depth). The pectoral fins are normally held against the body, but when threatened the fins are expanded in to scare...

Fish round-up : the basking shark

par Ksso le 25 mai 2011

While I never actually encountered one of those, basking sharks have fascinated me since I started scuba diving and learned about them. Basking sharks are the second largest living fish on earth, just after the whale shark.Wikipedia reports that the largest accurately-measured specimen was trapped in a herring net in the Bay of Fundy, Canada in 1851. Its total length was 12.27 metres (40.3 ft), and it weighed an estimated 19 short tons (17 t). Despite the fact that the beast is huge, it's perfectly harmless to humans : it's a slow mover that feeds by filtering water to catch plankton, small fish and invertebrates, basking in the warmer waters at the surface. The teeth in the basking shark...

Fish round-up : the Doplhinfish

par Ksso le 20 mai 2011

Dolphinfishes are fairly big creatures (often over 1m) from the family of ray-finned fish. The family has only one genus, Coryphaena, which contains two species, the "Mahi-Mahi" and "Pompano Dolphinfish". They are unrelated to dolphins as they are no mammals.Mahi-mahi means very strong in Hawaiian. Mahi-Mahis can live up to 4 years, weight up to 18kg (40 lbs) and measure up to 2m and are usually bigger than Pompano Dolphinfishes which are often mistaken with teen Mahi-Mahis.Mahi-mahi can be found in the Caribbean Sea, on the west coast of North and South America, the Pacific coast of Costa Rica, the Gulf of Mexico, the Atlantic coast of Florida, Southeast Asia, Hawaii and many other...

Fish round-up: deep-sea "Tortugas Red" jellyfish

par Ksso le 16 mai 2011

As I was researching jellyfishes, I ended up gazing on this "Tortugas red" species. As you may have realized, jellyfishes are usually transparent-ish. They can be bioluminescent, they can diffract the light creating rainbow effects... but a red jellyfish that's something really rare.The Tortugas red is part of the "Ctenophora" phylum (one of the 40 divisions of the animalia kingdom) and populates cold waters all over the globe. It lives in deep water which is probably what got it its strong pigmentation.Unfortunately, not much is know about this species that has not even been properly described. The picture above is one of the few proving its existence and dates back from 1984 in Boreal...