Diamond Squid (Thysanoteuthis rhombus)

Also known as the diamondback squid, the diamond squid is a large species of thysanoteuthid squid that occurs in tropical and subtropical waters worldwide. Like other squids diamond squids are hunters and will hunt near the surface at night. They will ‘retreat’ to midwaters during the day. Diamond squid have unusually short arms and large fins which earn them their common name.

Diamond squid are noted for their unique “pyrosome-like” egg masses that float near the ocean’s surface.

Classification

Animalia-Mollusca-Cephalopoda-Coleoidea-Teuthida-Oegopsina-Thysanoteuthidae-Tysanoteuthis-T. rhombus

Image: John Arnold

The Global Kraken

The team found that the giant squid’s genetic diversity is incredibly low. Even though the individuals hailed from opposite corners of the world, they differed at less than 1 in every 100 DNA letters. For comparison, that’s 44 times less diverse than the Humboldt squid, which only lives in the eastern Pacific. In fact, the giant squid seems to be genetically narrower than any other sea-going species that scientists have tested, with the sole exception of the basking shark.

This strongly suggests that the 21 proposed species of giant squid can indeed be collapsed into one. There’s just the one global kraken—Architeuthis dux, the one-and-only original. What’s more, the population seems to have very little structure—in other words, squids that hail from nearby waters aren’t going to be genetically closer than distant individuals. The mitochondrial DNA of a Japanese squid is basically the same as that of a Floridian squid.

Why? It’s possible that the adults are wandering nomads that swim over large areas, but that seems unlikely. Chemical analyses of their beaks suggest that they stick within a relatively contained patch of ocean. The alternative is that they go a-wanderin’ as larvae and youngsters. Young marine animals are certainly capable of passively drifting over tens of thousands of kilometres on ocean currents, so it’s entirely possible that the squids do the same. These young nomads would feed on plankton and other small creatures until they became big, whereupon they’d settle down and sink to the nutrient-rich waters of the deep ocean.

(via Phenomena: Not Exactly Rocket Science)

 Dave sighed. He longed to go to Lucrezia, to comfort her, to caress her, but he could not, and so he remained outside, just below her window, watching and listening. He thought of her silky auburn hair and dancing gray eyes. His mouth filled with the bittersweet taste of longing. The first flush of dawn chased him away, but before he left, he thrust a note beneath her window sash.  

I have watched from the shadows;
you are brighter than sunlight


 
It might have been more poetic than literal, but he meant it truly; hers was a warmth that would not burn him to ash – though it did seem to have seared its way into his heart.

2

Bigfin Squid (Genus Magnapinna)

bigfin squid are a family of elusive squid presumably found in deep Atlantic waters. Only several specimens of these unusual squid have been observed and as such not much it known about them. It is speculated that they drag their long arms across the sea floor scooping up any food that bumps their tentacles. It is also thought they could live a more lazy lifestyle floating in the water column waiting for prey to bump into their tentacles.

Phylogeny

Animalia-Mollusca-Cephalopoda-Teuthida-Oegopsina-Magnapinnidae-Magnapinna

Image source(s)

Joubin’s Squid (Joubiniteuthis portieri)

….is a small species of squid found in the Atlantic Ocean, Pacific Ocean and rarely in the Indian Ocean. This species is noted for its extremely thin mantle, long tail and long arms. Like the bigfin squid it is thought that the squid dangles its long tentacles in the water column in hopes of catching passing food.

Phylogeny

Animalia-Mollusca-Cephalopoda-Teuthida-Oegopsina-Joubiniteuthidae-Joubinieteuthis-portieri

Image Source

Text
Photo
Quote
Link
Chat
Audio
Video