Porcupinefish - Pufferfish
& Triggerfish

Group 10: Odd Shaped Swimmers

Porcupinefish - Pufferfish & Triggerfish

Group 10 - Odd shaped swimmers : This group of fish contain families that are unusual in their shape, but are swimmers rather than bottom dwellers.

Reef Cornetfish (pez corneta, Fistularia commersonii)

Cornetfish are very long slender members of the Trumpetfish family, reaching a size of up to 6 feet. Their mouths are flared at the end like a coronet. To confirm their ID, look for a long, whip-like filament on the end of their tail. (Size 1.5-3 feet, max 4 ft.)

Balloonfish (pez erizo, Diodon holocanthus)

Balloonfish are the smaller of our two porcupinefish. Their long spines and clear fins are both ID keys. Think of a long spine to pop a clear balloon. (Size 8-14”, max 20”)

Spotted Porcupinefish (pez puercoespinas, Diodon hystrix)

The spotted porcupine can reach a size of up to 3 feet. Remember that it has spots on its fins and is as big as a porcupine. (Size 1-2 feet, max. 3 ft)

Guineafowl Puffer (botete, Arothron meleagris)

The guineafowl puffer has white spots over a black body (it is also known as the spotted puffer in other parts of the Pacific). The mouth is protruding and blunt. There is a golden phase, characterized by a bright yellow gold body with a few black spots and a whitish belly. Individuals can change between the two phases. The regular phase should not be confused with the female Pacific boxfish (Ostracion melegris), which has the same black and white markings but a distinct box/trunk shape. (Size 6-10”, max. 12”)

Spotted Sharpnose Puffer (botete bonito, Canthigaster punctatissima)

The spotted sharpnose puffer looks much like the guineafowl but with a brownish body rather than black. The mouth also protrudes, but comes to a sharp point, hence the name sharpnose puffer. There is also a big difference in size, the spotted sharpnose is much smaller than the guineafowl. (Size 2-3.5”, max. 4”)

Finescale Triggerfish (cochi, Balistes polylepsis)

The finescale triggerfish is a large triggerfish that has no distinct markings but a dull gray coloration over its body. The scales are small and fine on the finescale. (Size 1-2 feet, max. 2.5 ft)

Orangeside Triggerfish (cochino, Sufflamen verres)

The orangeside triggerfish has a distinct yellow to orange belly region. These triggers are often found in deeper water and are generally very wary, keeping their distance from divers. (Size 8-12”, max. 16”)

Yellowtailed/Mexican Goatfish (salmonete barbon, Mulloidichthys dentatus)

Goatfish have distinct barbels hanging from under their chin. These barbels are used when feeding in the sand to taste and feel for the small shrimp and crustaceans that are hiding there. Think of the barbels as billygoat whiskers. (Size 6-9”, max. 12”)

Rock Croaker, adult (corvinita gungo, Pareques viola)

The rock croaker hides under rocky ledges and crevices during the day and ventures out at night to feed. It could almost be classified with the reddish nocturnal fish, but for its chocolate brown coloration. The general body shape, behavior, and higher first dorsal will help you distinguish this fish. (Max. size 10”)

Chinese Trumpetfish (Aulostomus chinensis)

A medium-sized fish which grows up to 80 cm in length. Its body is elongated and compressed laterally, with a long, tubular snout which has a small barbel at its inferior extremity. The protrusible mouth can be extended forward to catch prey. The pelvic fins are located in the middle of the body and are small, with one basal black spot.

The body coloration can be uniform or mottled in a range of grey, brown, or dark green. Some fish are uniformly bright yellow. The rear part of the body is normally black with white dots. Two black spots are present on the tail.

Spotted Boxfish (Ostracion meleagris )

A species of boxfish found in the Indian and Pacific Oceans. It is found on reefs at depths of from 1 to 30 metres (3.3 to 98.4 feet). This species grows to a length of 25 centimetres (9.8 inches). Males and females differ in colour: males are blackish on the back with white spots, and have bluish sides with bright yellowish bands and spots. Females and juveniles are dark brown to blackish with white spots.

Honeycomb Puffer (Canthigaster janthimoptera)

Their base colour is brown to orangish (especially around the head and back) and it’s covered in white spots on their body. On the head and over the back of the animal, these spots are greenish. Just below the dorsal fin is a large spot. This puffer looks very similar to C. punctatissima, but that species doesn’t have the large spot below the dorsal fin.

Whitespotted Puffer (Arothron hispidus)

A medium to large-sized puffer fish, it can reach 50 cm length. It is light grey in color, or greyish or yellowish, and clearly covered with more or less regular white points, that become concentric contrasting white and dark grey lines that radiate around the eyes and pectoral fins.

Longnose Puffer (Sphoeroides lobatus)

The Longnose Puffer has a moderately elongated body that are inflatable. They are an olive-brown color with mottling and numerous small light blue spots. Their ventral side is white and unusually flat. They have a horizontal row of short brown bars at the transition between their lower sides and the underside of their body. They have skin flaps on their back with a large black blotch behind each. Their head has a long narrow snout and is concave between their large elevated eyes. The Longnose Puffer reside on the bottom and are found in sandy and weedy areas at depths up to 107 m (350 feet). They reach a maximum length of 30 cm (12 inches).

Blunthead Triggerfish (Pseudobalistes naufragium)

Angular oval-shaped body with broad dark bands which are often broken and blotchy, a network of narrow oblique blue lines on body turning into scribbles on back and tail base, and blue spots on face. Dorsal and anal fins high, and used for primary swimming propulsion.

Scrawled Filefish (Aluterus scriptus)

medium size fish which can grow up to 110 cm (3.6 ft) in length. The body shape looks like an elongated oval, strongly compressed. Its background body coloration is olive-brown or grey depending on its surrounding environment, irregular blue lines and spots are distributed on the body mixed with some black spots mainly on the head. The colors may quickly vary depending on background similar to an octopus's.

Flaftail Tilefish (Malacanthus brevirostris)

Long and slender body, with a rounded head and a large, sharp spine in the centre of the gill cover. It has an overall colour of greyish with a yellow hue on the head. The back is marked within distinct chevron-shaped bars. There are two convergent black stripes, one each on the upper and lower lobes of the caudal fin. They are largely found in barren and open areas of outer reef slope where they are typically encountered in pairs living on sand in a hole that they have excavated. When threatened, they take refuge into their burrow. They have a pelagic stage to at least 5 cm (2.0 in). They feed on small fishes and invertebrates.

Pacific Seahorse (Hippocampus ingens)

Hippocampus ingens are one of the largest seahorses, with adult pacific seahorses ranging in size from 12 to 19 centimetres (4.7 to 7.5 in) in height. Pacific seahorses can be a variety of colors, including green, brown, maroon, grey, and yellow. Males can be distinguished from females by their prominent keel.

Choose another fish Category

1. Disks and Ovals / Colorful

The first category of disk and oval shaped fish are very important to learn. They are colorful, large and very obvious and the three main families that make up the group can be found on almost every dive.

2. Silvery Fish

Silvery fish have many different family members, though we will look at just a few representatives. As opposed to the colorful butterfly, angel and surgeonfish, the silvery fish tend to blend in better in open water and are usually not found near the colorful bottom.

3. Sloping Head / Tapered Body

This third group of “fish-like” fish, are very important to learn. The are common on most dives and are also highly sought after as food fish. It is especially important to monitor these fish to provide data for fisheries management. Snappers can be very difficult to tell apart from the similarly shaped grunts. One helpful hint is to look at their tails. Snappers tend to have straight, flat tails. They are also known for their habit of snapping their mouth open and shut when caught on hook and line. They have very sharp canine teeth that can provide a nasty bite to the unsuspecting angler. Look closely on your next dive and you may see the small teeth protruding from the side of the mouth. Grunts on the other hand, have slightly notched tails. They get their name from the grunting sounds they emit when threatened. These sounds are created by rubbing together bony teeth plates located in the back of the throat. Since the teeth are in the throat, a diver will never see protruding teeth on a grunt, only big blubbery fish lips.

4. Small Ovals / Damselfish

While divers tend to first notice the larger, more obvious fish on a dive, after a short while the challenge to find new species leads them to change their search image to look for smaller, previously unnoticed fish. Generally, the first new species a diver will encounter will belong to the small oval shaped group. This group is broken into the damselfish and their close cousins the chromis. Damsels are like the surgeonfish in that they eat algae. They do not roam around grazing, but rather tend to small algae gardens like a farmer. These areas are guarded fiercely as the algae farm is the damsels food source. For that reason you can think of the damselfish as not just territorial, but Dam- selfish with its territory. Many damselfish have distinctly different colors as juveniles, often being much brighter and more colorful when they are young and becoming drab with age. (much like us humans!) For this reason, the juveniles have been heavily collected for the aquarium trade and are under heavy fishing pressure. As part of the REEF Fish Survey Project, divers are asked to monitor the juveniles and adults separately in two of the damselfish species – the Cortez damselfish and the giant damselfish.

5. Heavy Body / Large Lips

Heavy bodied, large lipped fish belong to the seabass family. We tend to refer to the larger seabasses as groupers and the smaller seabasses as bass or basslets. These fish are extremely important food fish and are under increasing threats from heavy fishing pressures. Monitoring these fish can help provide valuable data to aid in their protection. Most seabasses are hermaphrodites, meaning the same fish will be both a male and a female during its lifetime. The groupers are all born female and later change sex to become male. Most large groupers also congregate each year to spawn at a specific location, making them easy targets for emerging positioning and fishing technology.

6. Swim with Pectorals / Obvious Scales

The fish in this group all use their pectoral fins to swim with rather than the traditional tail swimming of most other fish. The scales are also quite large and obvious. These fish can also be hermaphrodites, like the groupers, with some fish changing sex and others staying the same. Intermediate and adult fish often have very different appearances compared to the always-male terminal phase. This means learning two colors to be able to ID the same species of fish. Most of the pictures shown in this curriculum are terminal phase males, unless noted.

7. Redish / Big Eyes

This group of reddish fish is normally not seen during day dives due to their nocturnal nature. The reddish color helps them blend in at night and the large eyes help them to see better.

8. Small, Elongated Bottom Dwellers

The small bottom dwelling fish often make up the most interesting fish to watch during your dive. Their approachable nature and interesting behaviors make them great fishwatching finds. Blennies tend to be slightly larger than gobies, but are most easily recognized by their curved body posture and expressive faces. Gobies, though similar in their habitat requirements, tend to sit flat and straight on the bottom. The jawfishes actually live in a burrow in the sand that they excavate and maintain.

9. Odd-Shaped Bottom-Dwellers

This category of fish is made up of families and species that didn’t quite fit anywhere else due to their unique body shapes.

10. Odd-Shaped Swimmers

This group of fish contain families that are unusual in their shape, but are swimmers rather than bottom dwellers.

11. Eels

Though looking like snakes, eels are fish. There are several different types of eels, and we will look at two – garden eels that live in burrows in the sand and moray eels. Moray eels have a bad reputation mainly due to the constant opening and closing of their sharp toothed mouths. However, this is not a threat to divers, as this action pumps water through their gills. Most eels are actually very shy.

12. Sharks & Rays

Even though the sharks and rays are cartilaginous (their skeletons are made of cartilage instead of bones), they are still referred to as fish and count during our surveys.

5 Fun Facts - Pufferfish

Pufferfish are a testament to the diversity and wonder of marine life. Their unique characteristics and behaviours continue to captivate divers and snorkelers. The family of the pufferfish consists of over 120 species and are not only beautiful but also play a crucial role in the delicate balance of our underwater ecosystems, making them a joy to observe for snorkelers and divers alike. Here are some fun facts about these remarkable fish:

BLOG - Pufferfish in Costa Rica

Inflatable Superstars: Pufferfish are famous for their ability to inflate themselves when threatened. They gulp down water (or air) to puff up, turning into an intimidating ball-like shape to deter predators. This defense mechanism can make them appear several times their normal size!

Deadly Delicacies: Some species of pufferfish, particularly the Japanese fugu, are considered delicacies in Asian cuisine. However, they are also highly toxic. To humans, tetrodotoxin is deadly, up to 1200 times more poisonous than cyanide. There is enough toxin in one pufferfish to kill 30 adult humans, and there is no known antidote.Chefs who prepare fugu undergo rigorous training to ensure they remove the poisonous parts and serve only the safe, delicious flesh.

Efficient Predators: Despite their slow and clumsy appearance, pufferfish are skilled predators. They use their sharp beaks to crush shells and consume hard-shelled prey like crabs and snails.

Conservation Concerns: Pufferfish populations are threatened by habitat destruction, overfishing, and the illegal pet trade. Some species are listed as vulnerable or endangered, highlighting the importance of conservation efforts to protect these intriguing creatures.

Cute minefields: Here in Guanacaste the pufferfish are showing some very unique behaviour. On some our local dive sites we find large schools of pufferfish schooling together. Estudiantes is one of the best dive-sites to find yourself diving amidst these cute little floating mine fields.