B İ O L O G Y
• All bony fish possess gills. For the majority this is their sole or main means of respiration.
Lungfish and other osteichthyan species are capable of respiration through lungs or
vascularized swim bladders. Other species can respire through their skin, intestines,
and/or stomach.[21]
•
• Osteichthyes are primitively ectothermic (cold blooded), meaning that their body
temperature is dependent on that of the water. But some of the larger marine
osteichthyids, such as the opah,[22][23] swordfish[24][25] and tuna[26][27] have
independently evolved various levels of endothermy. Bony fish can be any type of
heterotroph: numerous species of omnivore, carnivore, herbivore, filter-feeder or
detritivore are documented.
•
• Some bony fish are hermaphrodites, and a number of species exhibit parthenogenesis.
Fertilization is usually external, but can be internal. Development is usually oviparous
(egg-laying) but can be ovoviviparous, or viviparous. Although there is usually no
parental care after birth, before birth parents may scatter, hide, guard or brood eggs,
with sea horses being notable in that the males undergo a form of «pregnancy»,
brooding eggs deposited in a ventral pouch by a female.