crustacean

CRUSTACEAN
- OVER 30,000 SPECIES, INCLUDING PRAWNS, SHRIMPS, LOBSTERS AND CRABS.
- MOST VALUABLE FISHERIES: NATANTIAN DECAPODS (PRAWNS AND SHRIMPS) & REPTANTIAN DECAPODS.

1. NATANTIAN DECAPOD (Swimming decapods)
- MOST EXPLOITED: CARIDEA AND PENAEIDEA
1.1. CARIDEANS
- CARIDEANS DIFFER FROM PENAEIDS IN THAT THE PLEURON (COVERING SHELL) OF THE 2nd ABDOMINAL OVERLAPS THE PLEURA OF BOTH 1st AND 3rd SEGMENTS. THEY CARRY FERTILIZED EGGS EXTERNALLY BENEATH THEIR ABDOMEN
- MOST COMMERCIALLY IMPORTANT SPECIES BELONG TO FAMILY PANDALIDS; INCLUDING THE COLD AND TEMPERATE WATER SHRIMPS OF THE GENUS Pandalus, Heterocarpus (DEEP-WATER PANDALIDS) AND Macrobrachium.
- IMPORTANT SPECIES: Pandalus borealis, P. platyceros, and P. jordani, Macrobrachium rosenbergii.


Macrobrachium rosenbergii




Litopenaeus vannamei

1.2. PENAEID PRAWNS
- THE DISTRIBUTION IS GENERALLY RESTRICTED IN TROPICAL AND SUBTROPICAL WATERS.
- BECAUSE REQUIRING BRACKISHWATER, THEY ARE FOUND IN AREAS WITH SUFFICIENT RAINFALL
- THE PRICES ARE VERY EXPENSIVE
- PREVIOUSLY 2 GENERA: Penaeus AND Metapenaeus
- CURRENTLY PENAEUS IS DIVIDED INTO 6 GENERA, I.E. Penaeus, Metapenaeus, Plesiopenaeus, Metapenaeopsis, Xiphopenaeus and Trachypenaeus
- MOST PENAEID PRAWNS CAN BE IDENTIFIED BY THE NUMBER OF “TEETH” ON THE ROSTRUM AND THE SCULPTURING OF THE CARAPACE
- ALL COMMERCIALLY IMPORTANT PENAEID PRAWNS HAVE SEPARATE SEXES, AND THE FEMALE, WHICH IS USUALLY LARGER THAN MALE, PRODUCED SEVERAL HUNDRED THOUSAND EGGS IN OVARIES
- MOST IMPORTANT SPECIES OF PENAEID SHRIMP: Penaeus monodon (Tiger prawn), Marsupenaeus japonicus (Kuruma prawn), Litopenaeus vannamei (Pacific white shrimp), Penaeus semisulcatus (Flower prawn), Fenneropenaeus merguiensis (Banana prawn)
- Find the pictures of those species

2. REPTANTIAN DECAPODS (Walking decapods)
- INCLUDE LOBSTER AND CRABS
- GENERALLY ADAPTED FOR A BENTHIC HABIT, SOME COULD SWIM, E.G. SWIMMING CRABS (fam. Portunidae) AND SLIPPER LOBSTER (fam. Scyllaridae).

2.1. ASTACURA
- INCLUDE LARGE CLAWED LOBSTER OF THE GENUS Homarus (H. gammarus & H. americanus), Norway lobster (fam. Nephropsidae)
- MALE ARE HEAVIER AND HAVE LARGER CLAW THAN FEMALE



Homarus gammarus

Panulirus ornatus

2.2. PALINURA
- DIVIDED INTO 2 DISTINC TYPES: (1) SLIPPER OR SHOVEL-NOSED LOBSTERS, (2) SPINY LOBSTER
- IMPORTANT FISHERIES IN WESTERN EUROPE AND THE MEDITERRANEAN
- GENUS Panulirus ARE MORE TROPICAL THAN Palinurus AND Jasus
- DISTRIBUTION RANGE of Panulirus, FROM NORTHERN LATITUDE, i.e. Panulirus interruptus and P. argus TO SOUTHERN LATITUDE, I.E. P. cygnus, P. ornatus, and P. penicillatus (INDO-PACIFIC REGION).



Slipper lobster (Parribacus japonicus)



Panulirus pennicilatus

2.3. BRACHYURA
- APPROX. 4500 SPECIES, INCLUDING TRUE CRABS.
- DISTRIBUTED OVER LARGE RANGE OF LATITUDES AND DEPTH.
- INCLUDING THE WORLD LARGEST CRUSTACEAN JAPANESE SPIDER CRAB Macrocheira kaempferi, WITH MAX. LENGTH FROM CLAW TO CLAW EXCEEDING 4 M.
- CANCER CRAB IS TYPICAL CRAB FAMOUS IN EUROPEAN AND AMERICAN MARKET (European crab Cancer pagurus, jonah crab C. borealis, rock crab C. irroratus, Dungenese crab C. magister)
- PRIMITIVE GROUP OF BURROWING CRAB, FROG CRAB Ranina ranina.

- MEMBERS OF FAMILY PORTUNIDAE ARE ECONOMICALLY VERY IMPORTANT, I.E. BLUE CRAB Callinectes sapidus (in Atlantic coast of America), mangrove crab Scylla serrata, swimming crab Portunus pelagicus.
- A GOURMET MARKET FOR SOFT-SHELLED BLUE CRABS IS MET BY CATCHING PREMOLT CRABS, WHICH ARE HELD IN FLOATING CAGES UNTIL JUST AFTER ECDYISIS.
- THE WORLD DEMAND FOR CRAB MEAT IS HIGH AND PREVIOUSLY UNEXPLOITED STOCKS ARE NOW FISHED HEAVILY.



Cancer pagurus

Portunus pelagicus

Scylla serrata

2.4. ANOMURA
- THE INFRA-ORDER ANOMURA CONTAINS SPECIES COMMONLY CALLED HERMIT CRABS.
- THE CRABS USE EMPTY SHELLS FOR SHELTER, NEVER KILLING THE ORIGINAL OCCUPANTS, AND SEEK LARGER SHELL TO ACCOMMODATE THEIR GROWTH.
- TWO GROUPS, I.E. LITHODID OR STONE CRABS AND THE COCONUT CRABS, HAVE EVOLVED AND NO LONGER DEPENDENT ON GASTROPOD SHELLS.
- LITHODID CRABS INCLUDE KING CRAB Paralithodes camtschatica, WHICH OCCURS FROM KOREA TO THE COAST OF CANADA. IT CAN REACH A MAX. OF 12 KG.

- THE FISHERY OF THIS SPECIES IS A MAJOR SOURCE OF CANNED AND FROZEN CRAB MEAT.
- THE COCONUT OR ROBBER CRAB Birgus latro, WHICH SPENDS MOST OF ITS LIFE CYCLE ON LAND, REACHES WEIGHT OF OVER 4 KG.
- THE ADULTS POSSESS MASSIVE CRUSHING CLAWS, AND LONG LEG TO CLIMB TREES, AND LARGE ADULTS ARE CAPABLE OF HUSKING AND BREAKING THROUGH THE SHELL OF FALLEN COCONUT.
- THIS SPECIES IS A HIGHLY VALUED FOOD ITEM IN MANY PARTS OF ITS RANGE, FROM INDIAN OCEAN TO PACIFIC OCEAN.


hermit crab


spider crab




Birgus latro