Cladocera
60
substrates, and also as ectoparasites on animals, from crabs and mollusks to
whales. In barnacles the fertilization is effectuated by a long tube (penis)
conducting the sperm to another individual. The pelagic larva develops
through several nauplius stages to a cypris larva. These larvae sometimes constitute an important part of the zooplankton (~meroplankton). After settlement of the cypris larvae, which attaches itself with cement glands on a suitable substrate, the metamorphosis will take place. A main feature is the formations of calcareous plates that form a kind of protective house, in which
the crustacean lives upside down. Food is collected by sweeping the biramous limbs (cirri, hence their name), which together form a kind of sieve,
through the water. If disturbed, or in tidal areas at emergence, the animal
retracts and closes the carapace. In the littoral zone barnacles can form by their
abundance conspicuous zones.
Cirripedia. (Barnes 1987)
Cladocera (cladocerans, water fleas) suborder of the order Diplostraca, class
Branchiopoda (subphylum Crustacea, phylum Arthropoda). Group of small planktonic crustaceans found mainly in freshwater, e.g., Daphnia. Marine species
do occur, e.g., Podon, living as zooplankton.
clams ~Bivalvia.
Clark-Bumpus zooplankton sampler ~zooplankton samplers.
clay (1) detrital particle of any composition smaller than 2 Ilm, which is the
upper limit of size of a particle that can show colloidal properties; (2) sediment composed primarily of clay-size particles and characterized by high
plasticity and by a considerable content of clay minerals. ~grain size and
~clay minerals.
clay minerals the constituents of a clay which give it its plastic properties. Clay
minerals are concentrated in a size less than about 2 Ilm. They are layer-lattice minerals occurring as minute, platy, sometimes curly or fibrous parti-
60
substrates, and also as ectoparasites on animals, from crabs and mollusks to
whales. In barnacles the fertilization is effectuated by a long tube (penis)
conducting the sperm to another individual. The pelagic larva develops
through several nauplius stages to a cypris larva. These larvae sometimes constitute an important part of the zooplankton (~meroplankton). After settlement of the cypris larvae, which attaches itself with cement glands on a suitable substrate, the metamorphosis will take place. A main feature is the formations of calcareous plates that form a kind of protective house, in which
the crustacean lives upside down. Food is collected by sweeping the biramous limbs (cirri, hence their name), which together form a kind of sieve,
through the water. If disturbed, or in tidal areas at emergence, the animal
retracts and closes the carapace. In the littoral zone barnacles can form by their
abundance conspicuous zones.
Cirripedia. (Barnes 1987)
Cladocera (cladocerans, water fleas) suborder of the order Diplostraca, class
Branchiopoda (subphylum Crustacea, phylum Arthropoda). Group of small planktonic crustaceans found mainly in freshwater, e.g., Daphnia. Marine species
do occur, e.g., Podon, living as zooplankton.
clams ~Bivalvia.
Clark-Bumpus zooplankton sampler ~zooplankton samplers.
clay (1) detrital particle of any composition smaller than 2 Ilm, which is the
upper limit of size of a particle that can show colloidal properties; (2) sediment composed primarily of clay-size particles and characterized by high
plasticity and by a considerable content of clay minerals. ~grain size and
~clay minerals.
clay minerals the constituents of a clay which give it its plastic properties. Clay
minerals are concentrated in a size less than about 2 Ilm. They are layer-lattice minerals occurring as minute, platy, sometimes curly or fibrous parti-