Crab Topics

This is often a very satisfying way whose only drawbacks are that it can be very time-consuming and that travel can be expensive.



BEACHCOMBING


Beachcombing is interesting that some crabs are specialized in the wet zone between low and high tide. Others live just below the waves touching the beaches, where they dwell around in an alien world between sand and water.


The best method to get out crabs from this substrate is by sieving sands. Go sit in the center of the waves and sieve the sand below you. Often there is no visibility in this area of the sea. Bringing up your sieve will yield nice surprises in many cases.


Another way of beachcombing is to watch small bubbles in the sand when a wave retracts: often there is a small crab or shrimp hidden there.


This is the world of the Matuta and other beauties.


High up on the beach, watch for holes: the Ocypods live there. They are mainly active at night, so a nightly visit to the beach occasionally will reveal sights of thousands of crabs walking around.



MUD FLATS


A close examination of mud flats exposed at low tide can produce many crustaceans not found in any other environment. Like on sand, on the mud flat the collector can use a rake or hand dredge, as well as a spade to dig out the deep-burrowing animals. Being able to recognize the tracks left by crawling or digging crabs or Upogebia plays an even greater role here than on the sandy beaches. A word of warning, mud can be a deadly trap and it is advisable to find out about the site and the tides.



ROCKY COASTS


Rocky coasts are often the home to specialized crabs, shrimps and lobsters. The collector can expect the best finds during the low spring tides. A flat knife and a long steel bar, slightly curved at one end, are standard equipment for hunting crabs along rocky coasts. The steel bar is useful to reach animals, which are hidden in rock crevices. Examine all the tide pools, the small caves and the algae. Do not forget to look under rocks.



THE OPEN SEA


Diving, dredging, and fishing for crustacean with traps or nets are very good methods to collect species that live out of the tidal range. However, all these methods require experience and often much expense.



DIVING AND SNORKELING


In shallow water you can "snorkel" with a minimum of standard equipment snorkel, mask, and flippers. Good lungs are important: the working depth is generally limited to 12 m. Better results are usually obtained by scuba diving. Air tanks permit the diver to explore the sea bottom thoroughly after suitable training. This method allows the collector to dive down to depths of 80 m, but 40 m is usually the limit for safe diving.



DREDGING


A dredge usually consists of a special net, which is designed to be pulled by a boat and dragged on the sea bottom. This can be a very productive way of collecting down to 60 m with a small boat. Museums and major institutions with proper research ships can dredge to depths of several kilometers and, in this way, can build up collections of deep-sea fauna, which is otherwise impossible to obtain.



FISHERMEN


Many crustaceans are edible and popular food, and thus are important to the fishing industry. A good relation with the local fisherman is important here. Visiting local fish-markets gives major results in obtaining the larger species of crustaceans.


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