No snake has gills so no.
Sea otters do not have gills because they are mammals.
They have gills and tubular feet
No. Like all snakes, sea snake use lungs to breathe. Because of this, they must periodically surface for air.
There are 55+ different species of sea snake here are a few: Yellow Sea Snake Yellow-lipped Sea Krait Crocker's Sea Snake Guinea's Sea Krait Blue-lipped Sea Krait Saint Girons' Sea Krait Niue Sea Krait Black-banded Sea Krait Black-and-yellow sea snake Spiny-headed Sea Snake Stoke's sea snake Turtlehead sea snake Jerdon's sea snake Yellowbelly sea snake (also known as pelagic sea snake) Olive sea snake Garman's sea snake Beaked seasnake Ornate Reef Seasnake
No.
actually yes yes they do. sea urchins have five gills that surround their mouth.
the most poisonous is the beaked sea snake
snake
the gills are located at the back of it's head
yes
if you mean by sea snakes, than yes. in fact, sea snakes are the most venomous type of snake in the world. the 10 most toxic sea snakes are the belchers sea snake( world's most venomous snake 100 times more venomous than the common taipan) banded sea snake, yellow bellied sea snake, Dubois's Reef sea snake, stoke sea snake, olive sea snake, elegant sea snake, electic sea snake, Fiji sea snake