[Ebook] Encyclopedia of Aquarium & Pond Fish – Directory of Marine Fish – Boxfish and Porcupinefish

Directory of Marine Fish

Boxfish and Porcupinefish

These fish have a distinctive appearance and can become surprisingly tame in aquarium surroundings. Characterized by a lack of streamlining, they cannot swim quickly to escape danger. They do, however, have other means of protection, such as the sharp spines of the porcupinefish. Take special care when catching and handling fish of this group, since many will release a poisonous mucus that, in the confines of an aquarium, will be deadly both to themselves and to the other tank inhabitants. The powerful jaws and teeth reflect their natural diet of marine crustaceans and mollusks. Aquarium specimens need similar foods in order to prevent their teeth from becoming overgrown.

Spiny Puffer (Diodon holocanthus)

• ORIGINS: Circumtropical, occurring in the Pacific and nEastern Atlantic; also Florida and the Bahamas to Brazil.
• SIZE: 9 in (22.5 cm).
• DIET: Plant matter and larger live foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.3–8.4) with SG 1.023–1.027.
• TEMPERAMENT: Do not mix with invertebrates.

The sharp teeth of these porcupinefish mean that, as with other larger members of this group, all electrical aquarium cabling should be protected, in case they attempt to bite through it. Cloudy eyes are a sign that porcupinefish have been kept in suboptimal water conditions. The total nitrate level must be kept below 20 ppm, with a water change of about 20 percent being advisable every two weeks.

Spotted Cube (Ostracion cubicus)

• ORIGINS: East Africa and the Red Sea through the Pacific to the Ryukyu Islands, east to Hawaii and Tuamotu.
• SIZE: 18 in (45 cm).
• DIET: Algae and various marine foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.3–8.4) with SG 1.023–1.027.
• TEMPERAMENT: Individuals can live with docile tankmates.

Only young fish of this species (pictured) display the stunning yellow coloration. Adults are dramatically different, with bluish bodies and pinkhumped noses. In mature specimens, the yellow areas are limited to mere lines, mainly on the sides of the face and at the base of the caudal fin. Do not mix this boxfish or similar species with cleaner fish, such as gobies or wrasse, since the cleaners will damage their thin skin.

Blue Boxfish (Ostracion meleagris)

• ORIGINS: From East Africa across the Pacific, via Australia’s Great Barrier Reef, and Hawaii to Mexico.
• SIZE: 6 1⁄4 in (16 cm).
• DIET: Omnivorous; fresh and thawed food, plus algae.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.3–8.4) with SG 1.023–1.027.
• TEMPERAMENT: Can live with nonaggressive companions.

Male and female Blue Boxfish look significantly different, with only males displaying the blue coloration. In contrast, females have white spots on a brownish-black background. Little is known about their reproductive behavior, and breeding in the tank is unlikely, as with other boxfish. They are easy to maintain but must not be housed with invertebrates, which form part of their diet in the wild.

Long-Horned Cowfish (Lactoria cornuta)

• ORIGINS: Red Sea through the Pacific to Japan, the eastern coast of Australia, and the Marquesas Islands.
• SIZE: 18 in (45 cm).
• DIET: Omnivorous; prefers algae and livefoods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.3–8.4) with SG 1.023–1.027.
• TEMPERAMENT: Aggressive to their own kind

The bony, hornlike projections on the head of this fish explain its common name. There is also a similar, less prominent projection at the rear of the body. The slow motion of the Long-Horned Cowfish means that it may lose out when competing for food with more agile fish, especially since it likes to feed near the tank bottom. If the flanks are drawn in, this indicates a serious loss of condition.

Saddled Toby (Canthigaster valentini)

• ORIGINS: Red Sea through the Indo-Pacific region to Japan and eastern Australia, as far as Tuamotu Islands.
• SIZE: 4 in (10 cm).
• DIET: Omnivorous; prefers algae and meaty foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.3–8.4) with SG 1.023–1.027.
• TEMPERAMENT: Nonaggressive.

These small fish make good home aquarium specimens because they can be housed in a modest tank. However, they should not be kept with invertebrates, which form their natural prey. The Saddled Toby can be distinguished from the Four-Barred Toby (C. coronata) by the presence of just three white horizontal bands across its back. Note, though, that a filefish called the Valentini Mimic (Paraluteres prionurus) has similar markings.

Humpback Turretfish (Tetrosomus gibbosus)

• ORIGINS: Indo-Pacific region, with specimens often originating from Sri Lanka.
• SIZE: 16 in (40 cm).
• DIET: Algae, plus prepared and fresh foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.3–8.4) with SG 1.023–1.027.
• TEMPERAMENT: Incompatible with invertebrates.

In common with related species, the Humpback Turretfish usually grows much smaller in aquariums than it does in the wild. Its body shape, combined with the way it swims, gives the impression that it is hovering in the water. Like other boxfish, it is protected by a rigid bony casing, augmented in the Humpback by various sharp projections along its sides, which help to deter would-be predators.

INFLATABLE ARMOR

When threatened, porcupinefish can defend themselves by inflating their bodies. This makes them harder to swallow, reinforcing the effectiveness of their armor of sharp spines. The teeth, normally used by the fish to obtain their food, can also deliver a painful bite to an attacker’s flesh. If lifted out into air after being caught, porcupinefish may inflate themselves with air instead of water, which can prove fatal. For this reason, they should be steered into a suitable submerged container of water, in which they can be taken safely out of the aquarium.

Striped Burrfish (Chilomycterus schoepfii)

• ORIGINS: Inhabits coastal waters, ranging from the north of Florida southward as far as Brazil.
• SIZE: 20 in (50 cm).
• DIET: Omnivorous; prefers algae and animal-based foods.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.3–8.4) with SG 1.023–1.027.
• TEMPERAMENT: Will attack invertebrates.

The spines of these fish offer good protection against predators, and the so-called “ocelli,” or false eyes, on their bodies also act as a deterrent against attack. Striped Burrfish must not be caught in a net, because their spines can easily become entangled in the mesh. As with similar fish, they can be greedy when feeding, which may place an extra burden on the tank’s filtration system, so water quality must be carefully monitored.