THE OCEAN DEEP

The moorish idol, Zanclus cornutus ("Crowned Scythe"), is a small perciform marine fish, the sole representative of the family Zanclidae (from the Greek zagkios, "oblique"). A common inhabitant of tropical to subtropical reefs and lagoons, the moorish idol is notable for its wide distribution throughout the Indo-Pacific. A number of butterflyfishes (all of the genus Heniochus) closely resemble the moorish idol.
It is said the moorish idol got its name from the Moors of Africa, who purportedly believe the fish to be a bringer of happiness. Moorish idols are also popular aquarium fish, but despite their popularity, they are notorious for their short aquarium lifespans and difficulty.
Physical description
With distinctively compressed and disk-like bodies, moorish idols stand out in contrasting bands of black, white and yellow which make them look very attractive to aquarium keepers. The fish have relatively small fins, except for the dorsal fin whose 6 or 7 spines are dramatically elongated to form a trailing, sickle-shaped crest called the philomantis extension. Moorish idols have small terminal mouths at the end of long, tubular snouts; many long bristle-like teeth line the mouth.
The eyes are set high on the fish's deeply-keeled bodies; in adults, perceptible bumps are located above each. The anal fin may have 2 or 3 spines. Moorish idols reach a maximum length of 23 cm. The sickle-like dorsal spines actually shorten with age.
Habitat and diet
Generally denizens of shallow waters, moorish idols prefer flat reefs. The fish may be found at depths from 3 to 180 m, in both murky and clear conditions. The range of the moorish idol includes East Africa, Indian Ocean and the Ducie Islands; Hawaii, southern Japan and all of Micronesia; they are also found from the southern Gulf of California south to Peru.
Sponges, tunicates and other benthic invertebrates constitute the bulk of the moorish idol's diet. Captive kept moorish idols typically are very picky eaters. They will either eat nothing (common) and perish or eat everything (very uncommon). Eating a variety of items is healthy. Even small portions of avocado and banana are sometimes fed in captivity.
Behavior and reproduction
Often glimpsed alone, moorish idols will also form pairs or occasionally small schools. They are diurnal fish, sticking to the bottom of the reef at night and adopting a drab coloration. Like the butterflyfishes, moorish idols mate for life; as juveniles, they are more apt to school. Adult males tend to be aggressive toward one another.
Moorish idols are pelagic spawners; that is, eggs and sperm are released in midwater and the fertilized eggs are left to drift away with the currents. The impressive range of these fish may be explained by the unusually long larval stage; the fish reach a length of 7.5 cm before becoming free-swimming juveniles. Before this time, the developing larvae will have drifted considerable distances.
Aquarium life
Moorish idols are notorious for being difficult to maintain in captivity. They require enormous tanks, often exceeding 200 U.S. gal, are voracious eaters, and are infamous for becoming incredibly destructive. Their captive survival rate is very low: most do not survive for a full year. Most that live past this mark typically die shortly thereafter. It is not recommended that any aquarist attempt to keep this species, because it is considered cruel by many and is nearly impossible (see diet). To avoid these shortfalls, some aquarists prefer to keep substitute species that look very similar to the Moorish Idol. These substitutes are all butterflyfishes of the genus Heniochus, and include the pennant coralfish, Heniochus acuminatus; threeband pennantfish, H. chrysostomus; and the false moorish idol, H. diphreutes.

The longhorn cowfish, Lactoria cornuta, is a variety of boxfish from the Ostraciidi family, recognisable by its long horns that protrude from the front of its head, rather like those of a cow or bull. They are a resident of the Indo-Pacific region and are usually around 10cm (4ins) long. Whilst badly suited to the home aquarium, the cowfish is becoming increasingly popular as a pet. Adults are often solitary and territorial, live around sand or rubble bottom up to a depth of 50 m. They are omnivorous, feeding upon benthic algae, various microorganisms, and oraminiferans that it strains from sediments, sponges, polychaete worms from sand flats, mollusks, small crustaceans, and small fishes, able to feed on benthic invertebrates by blowing jets of water into the sandy substrate.

Habitat
Primary habitat is coral reefs in lagoons, on reef flats, and on protected seaward reefs. Juveniles associate with Acropora corals. Depth range is 3.3–148 ft (1–45 m, perhaps up to 100 m).
Range
Red Sea and East Africa eastward through Indonesia to Marquesas, northward to southern Japan. Including Tuamotus, southern Korea, north to the Ryukyu Islands of southern Japan, south to Australia and Lord Howe Island, and off southern Africa in the Atlantic. Tropical and subtropical waters.
Maintenance:
Feed all kinds of live and frozen foods. The boxfish also eats greenstuffs. Best to feed small amounts several times a day. We generally feed squid, shrimp (the same kind people eat), mussels, and all kinds of chopped up fish. Be sure to wash these foods thoroughly before feeding. A good vegetable formula like Formula II is also beneficial. Live fish will also be taken but should not be fed exclusively.
Habitat: Natural geographic location:
Cowfish, Longhorn Cowfish, or Long-horned Cowfish are found in the Indo-Pacific: Red Sea and East Africa to the Marquesan and Tuamoto islands, north to southern Japan, south to Lord Howe Island. Inhabits inshore on coastal muddy or sandy habitats in still bays, and commonly found in harbours and estuaries. Small juveniles on protected shallow mudflats. Found in weedy areas near rocks or reefs. Juveniles often near river mouths and in brackish water. Adults are solitary, juveniles often form small groups. Large adults are shy. Feeds on benthic invertebrates by blowing away the sand
Physiology
There is no known sexual dimorphism, so both male and female display a yellow to olive base color, which is decorated with white or bluish spots. Paired courtship just before or after sunset. Eggs and larvae are pelagic.
One distinction from other fish is the lack of a gill cover, which is replaced by a small slit or hole. The hexagonal plate-like scales of these fish are fused together into a solid, triangular, box-like carapace, from which the fins and tail protrude. Their unique method of swimming, called ostraciform swimming, causes them to look as if they are hovering. They have no pelvic skeleton, so they lack pelvic fins. They are such slow swimmers cowfish are easily caught by hand, making a grunting noise when captured. This is the most well-known cowfish species in the aquarium trade.
Defence
If severely stressed, this species may be able to exude deadly toxin, ostracitoxin, an ichthyotoxic, hemolytic, heat-stable, non-dialyzable, non-protein poison in the mucous secretions of their skin. It is apparently unique among known fish poisons; it is toxic to boxfish and resembles red tide and sea cucumber toxins in general properties.
Foods:
All kinds of meaty foods and greenstuffs. A bottom feeder. Puffers are primarily predatory fish in the wild though they do graze on a bit of algae. This puffer will enjoy all kinds of meaty foods including shrimp, worms, clams, various mussels, snails, tunicates, and fish.They are not picky eaters and will quickly become adapted to a variety of prepared aquarium foods and an occasional algae wafer. Flake food is not recommended. Even though they may eat it, puffers will not thrive on it.
Social Behaviors:
Apparently this fish is sometimes aggressive and sometimes not. Keep an eye on newcomers with an established boxfish and any new boxfish that are added to the aquarium.
Sex: Sexual differences:
Apparently many boxfish are easy to sex but we haven't found this information yet.
Light: Recommended light levels:
No special requirements.
Temperature:
No special requirements. Normal temperatures for marine fish is between 74 and 79 degrees Fahrenheit.
Length/Diameter of fish:
Cowfish, Longhorn Cowfish, or Long-horned Cowfish adults can grow to 50.0 cm (20 inches). They usually only get about 40.0 cm (16 inches) in aquariums. Their size can be deceiving since they are usually very small at the pet stores.
Minimum Tank Length/Size:
A minimum 100 gallon aquarium is recommended.
Water Movement: Weak, Moderate, Strong
No special requirements.
Water Region: Top, Middle, Bottom
No special requirements.
Availability:
This fish is available from time to time.

The wahoo (Acanthocybium solandri) is a dark blue scombrid fish found worldwide in tropical and subtropical seas. Its speed and high-quality flesh make it a prize game fish. In Hawaii, the fish is known as ono. Hispanic areas of the Caribbean and Central America call it Peto.
Description
The body is elongated and covered with small, scarcely visible scales; the back is an iridescent blue-green, while the sides are silvery, with a pattern of vertical blue bars. These colors fade rapidly at death. The mouth is large, and both the upper and lower jaws have a somewhat sharper appearance than those of king or Spanish mackerel. Specimens have been recorded at up to 2.5 m (8 ft) in length, and weighing up to 83 kg (180 lb).[3] Growth can be rapid. One specimen tagged at 5 kg (11 lb) grew to 15 kg (33 lb) in one year. Wahoo can swim up to 80 km/h (50 mph), Firestein and Walters, 1969. They are one of the fastest fish in the sea.
The wahoo may be distinguished from the related king mackerel by a fold of skin which covers the mandible when its mouth is closed. In contrast, the mandible of the king mackerel is always visible as is also the case for Spanish and Cero mackerels. Their teeth are similar to those of king mackerel, but shorter and more closely set together. Do not get the Wahoo confused with the barracuda. They may look alike but in reality they are much different.
Biology
Wahoo tend to be solitary or occur in loose-knit groups of two or three fish, rather than in schools. Their diet consists essentially of other fish and squid.
Most wahoo taken have a trematode parasite (Hirudinella ventricosa) living in their stomach. It appears to do no harm to the fish.
Commercial usage
The flesh of the wahoo is delicate and white and regarded as very good in quality. This has created some demand for the wahoo as a premium priced commercial food fish. However, because of its solitary lifestyle, it is caught commercially only in the process with long-line fishery for tuna and dolphin (Mahi-mahi or dorado). Wherever found, it is a prized catch in sport fishing.