Aquatic and Marine Biology

Pisciculture is the controlled breeding and rearing of fish, usually for food. It is a specific branch of aquaculture. The study of birds is ornithology, the culture of honey bees is apiculture, and the study of snakes is ophiology.

Owls are nocturnal animals and their retinas are dominated by rod cells, which are highly sensitive to low light levels. This adaptation allows them to see well in the dark. Humans and many other diurnal animals have both rods and cones to facilitate both night and color vision.

A starfish is not a 'true fish' because it is an invertebrate belonging to the phylum Echinodermata, lacking a backbone and gills. Sharks, eels, and seahorses are all vertebrates that belong to the class of fish (Chondrichthyes or Osteichthyes).

It cannot be eaten by the humans, as it is very poisonous.

Whale is a mammal, while Tuna, Shark, and Cod are fish. Although Starfish is an invertebrate, Whale is the primary odd-one-out because it is a mammal.

In fishes, blood passes through the heart only once during a complete circuit of the body, which is known as single circulation. The heart pumps deoxygenated blood to the gills, where it is oxygenated and then sent directly to the rest of the body. Mammals, birds, and amphibians have double circulation or variations of it.

Birds and mammals have a completely four-chambered heart, which prevents the mixing of oxygenated and deoxygenated blood. Most reptiles have a three-chambered heart with a partial septum (except crocodiles), while amphibians have three chambers and fishes have two. This complete separation allows for a more efficient supply of oxygen to tissues.

Leeches produce an anti-coagulant called hirudin in their saliva to keep blood flowing while they feed.

Amphibians can live both on land as well as in water.

Sycon, a porifer, has water as a circulatory fluid.

The fish heart is known as branchial or venous heart because it only receives the venous blood and pumps it directly to the gills for oxygenation.

The scientific name for the zebrafish is Danio rerio. It is a popular model organism in scientific research.

Aquatic organisms are those that live in water. This category includes both marine organisms (saltwater) and freshwater organisms.

The tail fin of a fish acts as a rudder, allowing the fish to steer and change direction in the water. Other fins are primarily used for stability and propulsion.

Animals are classified by their habitats into aquatic (water), terrestrial (land), and amphibians (both). Since all these categories are listed, 'all of these' is the correct choice.