Search results
Results from the WOW.Com Content Network
A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found in most fish, in mammals such as whales, and in extinct ancient marine reptiles such as ichthyosaurs ...
The adipose fin is a soft, fleshy fin found on the back behind the dorsal fin and just forward of the caudal fin. It is absent in many fish families, but found in nine of the 31 euteleostean orders ( Percopsiformes , Myctophiformes , Aulopiformes , Stomiiformes , Salmoniformes , Osmeriformes , Characiformes , Siluriformes and Argentiniformes ...
The tail fin is rounded. The fish has an elongated oval shape as an adult and is laterally compressed. It is red in color, and all the fins may be yellowish except the pectorals, which are pink to colorless. The membranes between the dorsal spines may be slightly darkened to totally black, and the long pelvic fins may be quite dark.
There are six spines in the dorsal fin, the first spine being between three and four times longer than the second spine. There are 21 to 26 soft rays in the dorsal fin and 17 to 23 in the anal fin. The scales have low emarginated cross-shaped ridges. The upper part of the body is sivery bluish-grey with the lower hal;f being silvery-grey.
[37]: p. 219 In freshwater fish the bladder is a key site of absorption for many major ions [38] in marine fish urine is held in the bladder for extended periods to maximise water absorption. [38] The urinary bladders of fish and tetrapods are thought to be analogous while the former's swim-bladders and latter's lungs are considered homologous.
Discover the best free online games at AOL.com - Play board, card, casino, puzzle and many more online games while chatting with others in real-time.
This adaptation allows the fish to live in swamps where the water would otherwise be too low in oxygen content. The swim bladder can also be used to create sounds. [2] The reticulated knifefish produces a small number of relatively large eggs; the average fecundity is 500 eggs/kg of bodyweight, the eggs having a diameter of 3.6 mm (0.14 in).
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!