Image of a tropical fish

Fish are members of a set of organisms comprising all aquatic animals that have a skull, gills and do not possess limbs with digits. Fish are generally cold blooded, and can be found in all aquatic environments; exhibiting the greatest diversity among vertebrates with over 32,000 species. For humans, fish are an important resource as they provide food, oil and also have uses in medicine. Here is a list of some fish tourists can observe while snorkelling or diving at various locations around the world:

Batoid (Rays)

Batoids, more popularly known as rays or skates, are a category of cartilaginous fish closely related to sharks. They can be distinguished from sharks based on their flat bodies, big pectoral fins that are fused to the head and gills located on their ventral surfaces. The batoid family has a boneless skeleton made of a tough and elastic substance. These are sea-floor dwelling species and populate various geographical regions, with most batoids preferring tropical and sub-tropical aquatic environments. A few exceptions like the manta rays colonise the open sea, while a few live in freshwater as well. Unlike other fishes, bottom dwelling batoids breathe using their spiracles instead of their mouths. A majority of batoids have evolved heavy, rounded teeth that are used for crushing the shells of snails, oysters and other species which are generally found at the bottom of the ocean.

This type of fish can be found at places like the Ari Atoll in Maldives, Hurghada in Egypt, Utila in Honduras, Malpasacua in Philippines and Isla de la Juventud in Cuba.


The eel is a type of fish that, depending on the species, ranges in length from five centimetres to four metres. Their weight varies from 30 grams to over 25 kilograms, with the European conger being the heaviest eel, at a whopping 110 kilograms. Most species of eels have a dorsal and anal fin that is fused with the tail fin to form a single ribbon that runs along the length of the eel.

There are more than eight hundred varieties of eels in the world’s oceans. Most eels live as a group in eel holes. Famous in many cuisines as a delicacy, eels are considered as an important food resource. They are rarely spotted due to their nocturnal nature, with high chances of sighting at Garden Eel Reef, dive sites around Rarotonga in the Cook Islands and the Greek islands.


The seahorse is a marine fish named so for its equine appearance. Ranging in size from 0.6 to 14 inches, these are bony fish that, instead of having scales, have thin skin stretched over a number of bony plates. These bony plates make up the body in the form of rings, with the number of rings varying with the species. A peculiar characteristic of seahorses is their ability to swim upright, with another oddity being their possession of a well-defined neck. They are poor swimmers and use their prehensile tails to wrap themselves around a stationary object. Similar to chameleons, their eye movements are independent of each other. The male seahorse has a brood pouch on the front facing side of the tail in which the female deposits up to 1500 eggs, which the males carries for a period of nine to forty five days. The male’s duty ends with the release of these seahorses into the water and it offers no further care. Seahorse can be found in the Shetland Isles along UK’s west coast and also in the North Sea, along with diving sites in Bahamas and Bonaire.


The Jawfish is a small sized fish with a long body structure. Compared to its body, the jawfish has a large head, mouth and eye. Its dorsal fin is made of 9-12 spines, while the caudal fin is either round or pointed. They reside in burrows that are made of a sandy substrate, which are constructed by the jawfish stuffing sand in its mouth, which is then spat out elsewhere. Jawfish are generally not found swimming much, and prefer to remain near their burrows. They come in a variety of colours (blue and yellow being the most common) and are great to observe when snorkelling.

The jawfish is a territorial fish. Classified as mouthbreeders due to their eggs being hatched in the mouth, the newborn fish are protected from predators till they are strong enough to support themselves. Each species of jawfish has a varying gestation period. Over sixty species of jawfish have been described, and they are generally found in the shallow reef areas of the Atlantic and Pacific Ocean, as well as the Gulf of Mexico.


The billfish is a predatory species, which is recognised by its protruding bills and large sizes. The billfish is named so because of its snout, which is shaped like a spear-shaped bill. Of the billfish, the swordfish’s bill is the longest, comprising one-third its body length. Billfish typically include sailfish, marlin and swordfish. They consume a number of small fish and are identified as apex predators, though they have their own predators such as the Great White shark and Mako shark. These are highly migratory species that are found in all oceans, but are more widely present in tropical and sub-tropical waters.

The billfish makes use of its bill to cut and stun fish, by first running through the school, slashing and then returning to the impaled fish. Using their sword-like upper jaws, billfish stun and spear their prey when hunting. There have been a few instances of billfish accidentally spearing boats. Sports fishermen extensively hunt billfish due to their reputation as game fish. Having a fondness for the continental shelves, these fish avoid inshore waters and can be generally seen following the major ocean currents. Spotting sights for billfish include the Mexican Caribbean seas, Mozambique in South Africa, Marlin Alley in Mexico and the Togian islands in Sulawesi.