Shrimp

Crustaceans are a subphylum of a vast army of animals with jointed appendages in the phylum Arthropoda. Within this phylum is the order Decapoda, which includes almost all of the larger crustaceans. They usually have five pairs of legs serving diverse functions, claw-bearing limbs (chelipeds), two pairs of antennae, and a number of small appendages around the mouth that have various feeding functions. Shrimps also belong to this order. They have cylindrical carapaces and long, muscular tails with a tail fan or telson located behind the tail. Between the eyes there is an unusually pointed rostrum, which is an extension of the carapace. Most have long, flowing, delicate antennae. Shrimp shells are thin and pliant, never calcified like the crabs and lobsters. Many are capable of swimming by means of their legs or small paddles located under the tail called pleopods or swimmerets.

Pleocyemata

Shrimp with equal-sized pincers on all three front legs belong to the primitive suborder Dendrobranchiata. Commercially important pelagic shrimp are included in this order, which is very distantly related to other decapods.

The suborder Pleocyemata contains all the other decapods. The infraorder Caridea is found within this suborder in. Caridean shrimp have enlarged pincers on either the first or second pair of legs. The stenopodidean shrimp, located in another important infraorder, Stenopodidea, have enlarged pincers of the third pair of legs. Both contain bottom-dwelling shrimps.

Family Stenopodidae

Most of these reef-dwelling shrimp will act as cleaners when the opportunity arises, removing parasites and dead skin from their customers. They use their magnificently long curved, white antennae to advertise their availability. They hang out on the reef with their long pincers extended out in front of them in a defensive pose. This is why they are sometimes called boxing shrimp.

Banded Coral Shrimp
(Stenopus hispidus)

These are also known as Barber Pole Shrimp and Bandana Prawns. They are almost always found in pairs usually upside down under ledges and coral heads. You'll find that you'll notice their long, white antennae first, signaling its presence to eels and fish that a cleaner shrimp is available. Most are even active at night. Females are a little larger than males. You may find a light greenish blue egg mass held in place the female's abdomen by her swimmerets.

The Latin species name hispidus means bristly or spiny. This refers to the numerous, small, hooked spines on the upper surfaces of both body and legs. They point forward at the front end and backward at the rear end of the body.

Flameback Coral Shrimp
(Stenopus pyrsonotus)

This shrimp is perhaps best known as the Ghost Shrimp, suggested by its pale white color. It is also called the Fountain Shrimp because of the upward sweeping curve of its white antennae.

This Ghost Shrimp is larger and less common than its relative, the Banded Coral Shrimp. It is found at depths of thirty feet or more. It is also a cleaner shrimp. True to its family. It cleans mostly eels. The flame-red stripe on its back gives it the species name Fire Back.

The Ghost and the Slipper

This picture is an lucky shot of a Ghost Shrimp cleaning a Regal Slipper Lobster in a small cave. I had to shoot before they skittered away, which they did right after this picture was taken.

Family Palaemonidae

These are caridean shrimp, who have enlarged pincers on the second pair of legs. There are two subfamilies. The Pontoniinae are tiny shrimp, usually found living commensally on larger invertebrates. The other subfamily, the Palaemoninae are the numerous tiny shrimp found on rocks in shallow waters. They have long, pointed rostrums with a toothed-edge.

Clear Cleaner Shrimp
(Urocaridella antonbruunii)

This shrimp is a nocturnal cleaner of eels or sleeping fish. However, we have found them several times during the day with Yellowmargin Moray Eels. Its body is completely transparent and marked with bright red spots. It has light orange antennae and a white-tipped tail, bordered with red. The legs and pincers are banded red and white. These tiny shrimp can hover in the water column and even swim up to the fishes they clean.

Family Gnathopyllidae

These are the Leaf Jaws, a small family of caridean shrimp usually associated with echinoderms (urchins, stars, etc,) either as commensals or as predators. They are similar to pontoniine shrimp except that the third outward feeding appendages (maxillipeds) on both sides of the mouth have widened into leaf like plates. Pincers are borne on the first and second pair of legs. Those on the second pair are a little larger. They also have short, stout bodies with a flattened beak.

Harlequin Shrimp
(Hymenocera picta)

This rare fantastically beautiful animal has a white and cream body with large wine-red spots. Thin, banded plates cover its sides and legs, like a horse blanket. One pair of antennae has pennant like extensions. Moreover, the pincers have flattened into broad, brightly patterned leaf like plates. They feed on most species of sea stars in the area, including the infamous Crown-of-thorns Star. The shrimp turns them over and devours them alive over a period of days. It is assumed that this animal may be toxic, as are most brightly colored creatures.

These flamboyant, slow-moving shrimp usually occur in pairs with the females larger than the males. They appear to be territorial and seem to live in the same area for months or even years. I found these two in the photos, living far down in the coral heads and had to hold the strobe by hand to light from the side, since there was only room for the lens to fit from the front. A Blue-eye Damselfish kept butting in as you can see in this photo. I wasted a lot of film. I have spent many a dive waiting patiently by a coral head trying to lure these creatures out into the open, alas, to no avail.

Family Hippolytidae

Most of the shrimp in this cardean family have a hump on their tails. Hence the names humped-back shrimp or broken back shrimp are used for this family. Some are cleaners and a few live commensally with anemones or sponges.

Candy Cane Shrimp
(Parhippolyte mistica)

We have only seen this shrimp in caves, where it is usually found in groups. It goes out only at night. It has long antennae and fragile-looking legs. Its body is whitish and translucent with five or six encircling red bands. The genus name seems to translate into bearing or giving birth to a horse, which probably refers to the female of the species, whose bright yellow ovaries are often visible through the top of her translucent carapace, reminiscent of a saddle on a horse.

Marbled Shrimp
(Saron marmoratus)

The Latin translates to marbled broom, perhaps referring to its marbled appearance and the strange tufts of bristles on its body and first pair of legs. Indeed, it is also known as the Fuller Brush Shrimp. It is also often referred to as the Camel Shrimp, because of the hump on its tail.

This animal is abundant in Hawaii, but usually active only at night. In fact, we saw the shiny, beady eyes watching us through the darkness, long before we ever saw the animal itself. It is especially common in lush coral habitats. But it would scurry out of sight into the reef before we could get close enough to identify it. Either they have become used to us, or we are able to make a less threatening approach. We see them all the time now on night dives.

The males have absurdly long claw-bearing legs. They far exceed body length. They use these legs grappling and sparring with each other. These limbs shorten and thicken with age. The females display strange tufts of bristles on their bodies and first pair of legs. Male and female are so different that one can easily believe is one looking at two different species.