Search results
Results from the WOW.Com Content Network
The behavior of an amphibian hatchling, commonly referred to as a tadpole, is controlled by a few thousand neurons. [4] 99% of a Xenopus hatchling's first day after hatching is spent hanging from a thread of mucus secreted from near its mouth will eventually form; if it becomes detached from this thread, it will swim back and become reattached, usually within ten seconds. [4]
A hatchling still possesses a yolk sac upon which it depends for nutrition, and are thus also known as a sac fry. Fry – refers to a more developed hatchling whose yolk sac has almost disappeared, and its swim bladder is functional to the point where the fish can move around and perform limited foraging to nourish itself. [4]
A fish hatchery is a place for artificial breeding, hatching, and rearing through the early life stages of animals—finfish and shellfish in particular. [1] Hatcheries produce larval and juvenile fish , shellfish , and crustaceans , primarily to support the aquaculture industry where they are transferred to on-growing systems, such as fish ...
Hatchery fish escapees may in some cases compete with wild fish. [ 5 ] [ 6 ] There have been cases of more hatchery reared salmon being found in Canadian streams then wild reared salmon. This causes excess competition in wild salmon populations and can introduce unwanted genes and diseases. [ 7 ]
In fish, this often refers to the presence or absence of a stomach: precocial larvae have one at the onset of first feeding whereas altricial fish do not. [1] Depending on the species, the larvae may develop a functional stomach during metamorphosis (gastric) or remain stomachless (agastric).
If male pipefish and seahorses provide only a simple pouch for fish eggs to develop and hatch, it might not fully qualify as bona-fide pregnancy. However, current research suggests that in syngnathid species with well developed brood pouches, males do provide nutrients, osmoregulation and oxygenation to the embryos they carry.
The Australian lungfish has very complex courtship behaviour made up of three distinct phases. The first is the searching phase, when the fish will range over a large area, possibly searching for potential spawning sites. [32] A pair of fish will perform circling movements at the surface of the water close to beds of aquatic plants.
The latter allow them to use counter-illumination to escape predators that lurk in the depths: by matching the light intensity with the light penetrating the water from above, the fish does not appear darker if seen from below. They typically occur at a few hundred meters below the surface, but their entire depth range spans from 50 to 1,500 ...