#cartiliginous fish

[terry-the-insane]

Animal of the day for October 29: Great White Shark (Species Carcharodon carcharias)

The largest carnivorous shark, Great Whites travel hundreds of miles every day across the vast ocean in search of food. Great White Sharks have the ability to alternate between warm-blooded and cold-blooded metabolisms (heterothermy), which allows them to survive long periods without eating, or to explore colder waters. This would have likely given Great White Sharks and their kin an edge against other large sharks that existed, such as Alopias grandis or Hemipristis serra.

[marinebiologythisweek]

To start off this blog, check out this record-breaking Lamniform! The eyes can be a dead giveaway to who this guy is- the shortfin mako shark (also known as the Isurus Oxyrinchus (scientific name, named in 1810), bonito shark or blue pointer). Found in offshore temperate and tropical waters, the shortfin mako achieved the Guinness World Record on the 18th November 2011 for the fastest shark in the ocean with a top speed of 60 mph! That's as fast as some UK motorways, so don't expect to outswim them if you're on the run from them.

🦈

Quick facts:

Class:Chondrichthyes (jawed, cartiliginous fish and shark)

Subclass:Elasmobranchii

Genus: Isurus

Subdivision: Selachimorpha

Diet: mostly cephalopods (such as squid, octopus and cuttlefish), seabirds, porpoises and bony fish like mackerels, tunas, bonitos and even swordfish. They catch their prey by jumping up and tearing bits from their sides and fins. Makos swim underneath their prey so they can see above and have a good chance of getting to the prey before it sees them.

Lifespan: 29 years (M), 32 years (F)

Long ago, the Māori people in New Zealand wore necklaces and earrings made from shark teeth. The word "Mako" in their language means either "shark" or "shark tooth." Although longfin makos don't live in the waters around New Zealand, shortfin makos do, especially in the northern part of the country.

🔗links 🔗

Shark Trust (charity): British Sharks | The Shark Trust

[sepialunaris]

We are SO sleeping on how weird prehistoric fishes are. Like our legged fish ancestors or armored placoderms like Dunkleosteus are weird in their own way but they have nothing on them

Pycnodonts: literally any body shape they want that uncanny valley except some genera that look like normal trevallies

(Rostropycnodus, Stenoprotome, Gladiopycnodus, Maraldichthys by Joshua Knüppe)

Holocephali: cartiliginous fish closely related to chimaeras, which means they are relatives to sharks.

(Traquairius agkistrocephalus, Belantsea, and Squaloraja by Stanton F. Fink, Iniopterygidae by Ray Troll)

[sepialunaris]

Legit so many interesting OCs they killed too soon. The weird cartiliginous fish, the sword-nosed dolphins, crocosillians with super specific niches that they look like an ostrich, the weird ass reef fish taht died off. Disappointing.

no earth spoilers please, i’m only up to the cambrian explosion

[terry-the-insane]

Animal of the Day for November 19: Sand Tiger Shark (Species Carcharias taurus)

These sharks are widespread throughout the Pacific and Atlantic coasts. They look like an underwater demon if you ask me, but they're actually relatively harmless, with no confirmed human fatalities.

Sand Tiger Sharks are nocturnal and are benthic, mostly hunting prey that lives on the sea floor. Baby Sand Tiger Sharks are also cannibalistic, they will eat each other while still inside their mother's womb until only one embryo/fetus remains.

[sepialunaris]

Palaeozoic cartiliginous fish. They are weird. The potential we could've seen with 'sharks' occupying traditional bony fish niches.

Pycnodonts are bony fish but they are hella weird too (besides its type species Pycnodus, weirdly). And I also really like basal puffer or triggerfish ancestors they also look really unique.

What are some lesser known cool prehistoric non-reptile marine critters ?

Marine biology is a big special interest of mine but i don't know that much about it in terms of extinct taxa...