[Ebook] Encyclopedia of Aquarium & Pond Fish – Directory of Marine Invertebrates – Crustaceans

Directory of Marine Fish

Crustaceans

There are few more diverse invertebrate groups than the mollusks. Marine gastropod mollusks possess a protective shell and a “foot” for locomotion, just like the land snails. Bivalves, such as clams, have a two-part, hinged shell and a more sedentary lifestyle. The shell-less sea slugs can be difficult to maintain in aquariums, because their dietary requirements are so specific. Cephalopods, which include squid and octopuses, can also be problematic, since they require large tanks and are extremely sensitive to water conditions. Annelids, in contrast, are a group of segmented worms

Shame-Faced Crab (Calappa flammea)

• ORIGINS: Widely distributed through the entire Caribbean region.
• SIZE: Body is 8 in (20 cm) across.
• DIET: Live foods. Will scavenge for pieces of fish and shellfish, but be careful not to overfeed.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

Shame-Faced Crabs are so called because of the way in which they seem to hide their eyes behind their greatly enlarged claws. Although they often lie concealed under the substrate, these crabs can be rather disruptive in a typical reef tank, because they scavenge aggressively and prey on mollusks and other invertebrates. Shame-Faced Crabs do, however, get along well with fish such as gobies.

Porcelain Crab (Neopetrolisthes ohshimai)

• ORIGINS: The Indo-Pacific region, from the Asian coast south to Australia and east to the central Pacific.
• SIZE: Body is 1 in (2.5 cm) across.
• DIET: Will take freeze-dried and tablet foods. Try to direct food to the vicinity of the crab.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

These tiny crabs seek sanctuary from would-be predators by hiding among the stinging tentacles of sea anemones, to which they appear to be immune. Note that Porcelain Crabs will attack any clownfish introduced into the tank. They feed by trapping tiny particles of food with feathery projections on their jaws. Unfortunately, there is no way of sexing these crabs visually

Red Lobster (Enoplometopus occidentalis)

• ORIGINS: Found throughout the Indo-Pacific region, ranging as far east as the Hawaiian islands.
• SIZE: Body is 5 in (12.5 cm) long.
• DIET: Shrimp, fish, and food tablets. Try to ensure that the food is placed within the lobster’s reach.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

These strikingly colored lobsters are less conspicuous in the aquarium than their color would suggest. This is because they are nocturnal and usually hide during the daytime. Red Lobsters are territorial and will use their powerful claws to fight ferociously if they are housed together. These lobsters will prey on small fish, but they will also take inanimate foods.

Blade-Eyed Hermit Crab (Dardanus lagopodes)

• ORIGINS: From the Red Sea eastward throughout the entire Indo-Pacific region.
• SIZE: Body is 2 1⁄2 in (6 cm) long.
• DIET: Proprietary hermit crab food or meat-based foods, including pieces of fish and shellfish.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

Hermit crabs are unsuited to reef aquariums because they will prey on the occupants. They are best kept in a tank with nonaggressive fish, where they may prove useful in finishing off uneaten food. Hermit crabs do not have their own shells but take over those of mollusks, swapping to larger shells as they grow. Make sure there is a series of larger shells available in the tank for this purpose.

Purple Spiny Lobster (Panulirus versicolor)

• ORIGINS: The Pacific region, especially around Singapore and parts of Indonesia.
• SIZE: Body is 9 in (22.5 cm) long.
• DIET: Fish, shrimp, and tablet food. Should be fed a relatively small quantity once a day.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

This large lobster can be identified by its banded body patterning, striped legs, and the blue area on its tail. The antennae, which help the lobster to find food, are often longer than the body, so a spacious tank is required. If an antenna breaks off, it should regrow over successive molts, but not necessarily to its original length. The Purple Spiny Lobster can be housed safely with large companions.

Harlequin Swimming Crab (Lissocarcinus laevis)

• ORIGINS: Widely distributed throughout the entire Indo-Pacific region.
• SIZE: Body is 1 1⁄4 in (3 cm) across.
• DIET: Animal-based foods. Provide relatively small pieces that can be consumed easily.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

This red-and-white crab must always be housed alongside tube anemones, with which it forms a close association. Like other types of swimming crab, it has paddlelike hind legs that help it to swim efficiently. It is possible to sex this species by examining the underside of the body, since males have a narrower, more triangular abdominal region than females. Breeding in aquariums has yet to be achieved with this rather solitary crab.

Feather Star Squat Lobster (Allogalathea elegans)

• ORIGINS: Widely distributed throughout the entire Indo-Pacific region.
• SIZE: Body is 1 3⁄4 in (2 cm) long.
• DIET: Prefers thawed foods, but will also take small freeze-dried items.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

These tiny lobsters have a striped, egg-shaped body. They should not be mixed with larger predatory species of any kind. The tank must include Feather Starfish, since the lobsters live among their arms, avoiding detection by modifying their coloration so that they blend in with their hosts. Small crevices in nearby rockwork will serve as hiding places for these shy, retiring lobsters.

BOXING CHAMP

Some crustaceans evade danger by hiding under the sand, or among the stinging tentacles of anemones, while others rely on camouflage to conceal their presence. The Common Boxing Crab (Lybia tessellata), shown here, has a more direct way of protecting itself: it carries a small anemone in each claw and uses them like weapons. If threatened, the crab thrusts one claw forward, followed by the other, like a boxer delivering punches. This is enough to persuade most predators to back off. The Boxing Crab lets go of its anemones only when it molts, picking them up again when its new exoskeleton hardens. If the crab is challenged before this, it responds as though it were still holding the anemones.

Spotted Cleaner Shrimp (Periclimenes yucatanicus)

• ORIGINS: Occurs throughout the Caribbean region and in the western part of the Atlantic.
• SIZE: Body is 3⁄4 in (2 cm) long.
• DIET: Marine flake and small live foods. Often scavenges food given to its host anemone.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.02–1.024.

These shrimp have a yellow-and-white body, dark bands of red and white on their limbs, and white antennae. They need to be housed with a suitable host anemone, such as the Pink-Tipped Anemone (see p.286). Breeding is possible in aquariums; the female carries the green eggs under her abdomen. However, predation by other tank occupants makes it highly unlikely that any of the young will survive.

Scarlet Cleaner Shrimp (Lysmata debelius)

• ORIGINS: The Indo-Pacific region, ranging from the Maldives to Japan, Indonesia, and the Society Islands.
• SIZE: Body is 1 1⁄4 in (3 cm) long.
• DIET: Marine flake and small live foods. Try to ensure that food falls within reach of the shrimp.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

Scarlet-red coloration is a feature of these shrimp, which also display white spots on the body, white lower limbs, and white antennae. In reef aquariums, they are less shy if kept as a small group rather than on their own. Each maintains a small area of territory that includes a number of snug retreats.

Dancing Shrimp (Rhynchocinetes uritai)

• ORIGINS: Widely distributed throughout the entire Indo-Pacific region.
• SIZE: Body is 1 1⁄2 in (4 cm) long.
• DIET: Prepared foods, which can include marine flake. Will also eat small pieces of fish.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

Prominent eyes and a hump-backed appearance help to identify this crustacean. Males have larger claws than females. Dancing Shrimp are social by nature, but they will attack anemones that are not protected by stinging tentacles, and they will also eat coral polyps. Their movements resemble those of a tango dancer, advancing in a very deliberate fashion and then briefly pausing.

LIVING DANGEROUSLY

Cleaner Shrimp appear to have a death wish, actively seeking out and climbing all over fish that could easily snap them up. The potential predators refrain from devouring them because the shrimp use their powerful claws to remove parasites and skin debris from the bodies of the fish. The shrimp below (Lysmata amboinensis) is “cleaning” a Moray Eel (Gymnothorax species).

This arrangement helps to keep the eel healthy, while the shrimp gets to eat whatever it can remove. The shrimp tend to clean relatively sedentary fish species so that they are not carried off into the depths. How these relationships come about is unclear, because in aquariums the shrimp will even perform this service for fish that they do not encounter in the wild.

Marble Shrimp (Saron species)

• ORIGINS: Throughout the Indo-Pacific region, from the Red Sea, via Indonesia, to Hawaii.
• SIZE: Body is 1 1⁄4 in (3 cm) long.
• DIET: Eats small live foods, and will also scavenge in the tank for items such as marine flake.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

These sociable shrimp have marbled patterning— often a whitish-green with darker markings. They are shy and are unlikely to be seen during the day. When they do emerge, it quickly becomes obvious that their daytime coloration can be very different from their appearance at night. It is best to offer them food only after dark. Marble Shrimp should not be kept in a tank with live corals.

Coral Banded Shrimp (Stenopus hispidus)

• ORIGINS: Found on tropical reefs throughout the world’s oceans, particularly the Pacific.
• SIZE: Body is 2 1⁄2 in (6 cm) long.
• DIET: Meat-based foods. If frozen supplies are used, make sure that the food is thawed completely before use.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

The ancestors of these shrimp were present in the oceans more than 10 million years ago, when North and South America were still unattached continents. As the land bridge formed, the populations in the tropical regions of the Pacific and Atlantic became separated, resulting in different color forms and new species in different locations. Female Coral Banded Shrimp are larger than males. They also have bright red banding on their upperparts, which appears brownish in males. Keep these shrimp in true pairs, if not singly, because otherwise they will fight to the death. Tankmates need to be chosen carefully because these invertebrates will prey on other shrimp and smaller fish. The male Coral Banded Shrimp is unusual in that he collects food for the female and actively feeds her in a cave. She signals by clicking her pincers, and he responds by passing over food.

Pistol Shrimp (Synalpheus species)

• ORIGINS: Present in various forms in the Indo-Pacific, from the Red Sea to Japan and Hawaii.
• SIZE: Body is 1 1⁄2 in (4 cm) long.
• DIET: Small live foods and food tablets. As always, avoid overfeeding, since uneaten food will pollute the water.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

Pistol Shrimp have one enlarged claw that can produce a loud noise like a gunshot when it snaps together. The “shot” is so loud that it may sound as if the tank has shattered. Pistol Shrimp use these sound blasts to stun small prey. If the pistol claw is lost, the other claw will enlarge to compensate while the damaged limb regrows. Another key feature of Pistol Shrimp is their small eyes, which are partially obscured by the protective carapace.

Broken-Back Shrimp (Thor amboinensis)

• ORIGINS: Widely distributed throughout the Indo-Pacific region, including off the island of Amboina, Indonesia.
• SIZE: Body is 3⁄4 in (2 cm) long.
• DIET: Thawed or freeze-dried live foods. Offer food in proximity to the host anemone.
• WATER: Temperature 77–79°F (25–26°C); alkaline (pH 8.1–8.3) with SG 1.020–1.024.

This crustacean can be distinguished by its bold markings of dull orange and white and by the way in which it keeps its hindquarters raised above the rear of its body. It typically lives in association with Heteractis sea anemones, among which it scavenges for food. The Broken-Back Shrimp usually lies on top of its host, rather than retreating into its tentacles.

[Ebook] Encyclopedia of Aquarium & Pond Fish – David Alderton (Photo by Max Gibbs)