Hawaiian Lionfish, Pterois sphex
Endemic

The Hawaiian Lionfish is a nocturnal ambush predator. Mainly preying upon shrimp and small crabs the lionfish patrols the sleeping reef for its evening rations. With its venomous spines outstretched the lionfish is on guard in the case the hunter becomes the hunted.

Photo courtesy of: nmfs.noaa.gov

Hawaiian Cleaner Wrasse, Labroides phthirophagus
Found in Hawaii and Johnston Atoll

Found in most coral reef habitats except in the surge zone. Obligate cleaner, picks parasitic crustaceans from other fishes. Swims with a dancing-flitting motion. It spends the night resting in a balloon-like mucous cocoon. The surface mucus of host fishes appears to represent a stable food resource for cleaner fishes like Labroides phthirophagus. It is likely that host surface mucus provides cleaners with a reliable energy source in the form of carbohydrates while ectoparasites represent a less stable protein source.

Photo courtesy of: http://www.soest.hawaii.edu

Giant Trevally, Caranx ignobilis

Jacks are abundant in the NWHI. Hawaii is home to 24 different species of jacks but the Giant Trevally (Caranx ignobilis) rules the NWHI. Large and aggressive, we should expect to see these fish everywhere, in our face, and in the face of other large predators on the reef. Anecdotal evidence suggests that due to the territorial nature of the jacks we will see large schools moving in to chase off sharks and prey upon small reef fish and crustaceans.

Photo courtesy of: NOWRAMP

Pennantfish, Heniochus diphreutes

Red Sea and South Africa to warm-temperate Australia and the Hawaiian Islands Body is white with two broad oblique dark-brown bands running across the body from the dorsal fin to the abdomen and anal fin. A short brown band runs from the top of the head to the eye. The soft portion of the dorsal fin and the caudal fin are yellow. Occurs primarily along outer reef slopes. Juveniles in aggregations around isolated patch reefs, adults in large schools well above the bottom. Feeds on plankton. Juveniles may act as cleaners.

Photo courtesy of: http://www.blue-oceans.com

Galapagos Sharks, Carcharhinus galapagensis

A common but habitat-limited tropical shark found close inshore to well as offshore near or on insular or continental shelves. Prefers clear water with coral and rocky bottoms. Although a coastal pelagic species, it is capable of crossing considerable distances of open ocean between islands. Juveniles restricted to shallower water, in 25m or less. Found in superficial aggregations (groups of 30 have been reported in the NWHI). Tends to feed near the bottom but may take bait from the surface. Feeds mainly on bottom fishes (eels and triggerfish), also squid and octopi. Aggressive and dangerous to people, but in the NWHI more curious than aggressive. Like the gray reef shark the Galapagos shark has been know to perform an agonistic display prior to attack. 6 to 16 young of 57 to 80 cm are born per litter. An ontogenetic change in diet occurs as size increases. They consume a smaller proportion of teleosts and more elasmobranchs with increasing size. In the NWHI Galapagos sharks have been know to prey upon juvenile monk seals. Have been reported as the most abundant near shore shark in the NWHI.

Photo courtesy of: http://www.hawaiianatolls.org

Nurse Shark, Ginglymostoma cirratum

Found on continental and insular shelves. A solitary and sluggish fish, often encountered lying on the bottom. During daylight hours groups of up to 40 nurse sharks have been observed lying on the bottom (often in caves) nearly piled on each other. Nocturnal, feeding on bottom invertebrates such as spiny lobsters, shrimps, crabs, sea urchins, squids, octopi, snails and bivalves, and fishes like catfishes, mullets, puffers and stingrays. Ovoviviparous with 21 to 28 young in a litter. May attack humans if they are molested or stepped upon accidentally. Common over shallow sand flats, in channels, and around coral reefs. Algae is occasionally found in its stomach. This species feeds by sucking in food at high speed through its small mouth and large, bellows-like pharynx. It feeds on big, heavy-shelled conchs by flipping them over and extracting the snail from its shell, presumably with its teeth and by suction. Young nurse sharks have been observed resting with their snouts pointed upwards and their bodies supported off the bottom on their pectoral fins. Some suggest this posture may possibly provide a false shelter for crabs and small fishes that the shark ambushes and eats.

Photo courtesy of: http://www.calacademy.org

Green Sea Turtle, Chelonia mydas

The Hawaiian Green Sea Turtle is known by its Hawaiian name Honu. The carapace is a mottled dark brown on top and creamy white below. This counter shading conceals the turtle from predators; making it difficult to distinguish its dark upper carapace from the sea floor or its white plastron from the lighter sky. It is believed the green sea turtle reaches sexual maturity around 25 years and can live up to 80 years of age.

Upon sexual maturity the green sea turtle makes an amazing journey every two to three years to nest. They leave their feeding grounds in the main Hawaiian Islands and travel over 600 miles to French Frigate Shoals, their main breeding grounds, in the Northwest Hawaiian Islands. Here they will mate and lay their eggs on these small islands. The males can be distinguished from the females by its long tail. Mating starts in March and females lay their eggs between late-April and September. At night the female crawls onto the island to dig a body pit with its front flippers. The hind flippers are used to excavate an egg chamber. Females lay up to five or six clutches of eggs throughout the breeding season, with each clutch containing 100 to 120 ping-pong ball sized eggs. The female then gently covers the nest by flinging dirt over it with its flippers. Hatching begins in July after about 60 days of incubation, and occurs at night. Hatchlings weigh about one ounce and fit in the palm of your hand. Working as a group, hatchlings dig to the surface of the nest. During the cool night, the entire nest boils out of the sand and heads to the water, attracted to the light reflected off the ocean. Ghost crabs and reef fish pose a primary threat to the hatchlings.

After reaching the water, the hatchlings disappear and are not seen by humans until they appear as juveniles in the near-shore waters of the main Hawaiian Islands. Sea turtles start off as hatchlings weighing about one ounce and having a carapace length of 2 inches. Sexually mature turtles will have carapaces at least 2 1/2 feet long and weigh 200 -350 pounds. Adults grow to a carapace length of 3 1/2 feet and weigh an average of 400 pounds. Juvenile green sea turtles are omnivorous, feeding on plankton and fish eggs floating near the ocean surface. Adult Green sea turtles are primarily vegetarians feeding on near shore algae, or limu pastures. They don't travel far from their home feeding range, except when nesting.

Photo courtesy of: Jodi Harney, www.soest.hawaii.edu

Information courtesy of: http://www.pacificwhale.org

Spinner Dolphin, Stenella longirostris

The Spinner Dolphin is a slender creature with a long, thin beak to which the distinct forehead slopes gently. The dorsal varies with both age and geographical form; it can lean forward, be curved, or be completely triangular in shape. The flippers are long and pointed, and a stripe links it to the eyes. It has a dark gray or black dorsal cape, paler flanks and sides, and a creamy-white belly. It measure between 1.3 and 2.1m in length, and weigh between 45-75kg. The Spinner Dolphin occupies both offshore and inshore waters. This species takes midwater fish and squid, and is different from other dolphins in that it feeds by night. Units range from a few animals to a few thousand, often mixing with other cetacean species such as Pilot Whales and Spotted Dolphins. Spinner Dolphins are dramatically acrobatic, with somersaults, high spinning leaps and other aerial movements popular. They vocalize with whistles and clicks, and can travel as fast as 20kph.

Information and photo courtesy of: http://www.cetacea.org