Copepoda: (Meaning " ora-feet")
Scientific Classification:
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Hexanauplia
Subclass: Copepoda
1. Copepoda are
group of small crustacean are found in
freshwater and salt water.
2. Copepoda
very considerably but can typically be 1 to 2 mm (0.04 to 0.08 inch) long with
a tear drop shaped body and large antenna.
3.
Like other crustaceans like they
have an Armoured (provide with some kind
of defense). Exoskeleton but they
are small in most species, thin armoured and the entire body is almost transport.
4. The some polar copepods each in 1cm
(0.39inch). Most Copepod have single median compound eye, usually bright red
and in center of the transport head. Subterranean species may be eye less.
5. Like other crustacean, copepod 2 pair of
antenna, the first pair often long, conspicuous (easily seen) because of there are
small size of copepod have no need of any heart.
6. All
circulatory system (member of the order calanoida have a heart but no blood vessel) and most also lake gills.
7. Instead
they absorb oxygen directly into their body.
8. There
excretory system consist of Maxillary
glands.
Copepoda Reproduction:
Example : Reproduce
only during summer months and some species of Diaptomus and limnocalonus macrurus
have only one generation per year.
1.The antenna
and some genera modified 5th leg of the male are use in a clasping.
2. Male Calonoides (order of copepod
kind of zooplankton) have a single pore located a Symmetrically on the genital
segment.
3. But female
Calonoides both sexes in other free living.
4. During the
clasping the male transfer the sperm in female small packet like spermatopore,
usually with help aid of the legs.
5. The sperm
are store in a special ventral area of the female.
6. 2-Sexes
separated and has the egg leave in the female reproductive track.
7. This
process may be completed within a few minutes or as long 2-months after copulation.
8.
Fertilization of egg carried by the female in 1 or 2 Ovisacs. Ovisacs contain 5
to 40 eggs attached to the genital segment ventrally or sub-ventrally.
9. In some
species the cluth size varies seasonally
with the largest number of eggs being produce in the spring season.
10. Possibly
this variation is co-related with temperature or food condition.
Life Cycle:
Most non parasitic copepeods are holoplanktonic, meaning they stay planktonic for all of there life cycle, although harpacticoids, although free-living, tend to be benthic rather than planktonic. During mating, the male copepod grips the female with his first pair of antennae, which is some times modified this purpose. The male then produce an adhesive package of sperm and transfers it to the females, genital opening with his thoracic limbs. Egg are sometime laid directly into the water, but many species enclosed them with in a sac attached to the females body until the hatch. In some pond welling species, the egg have tough shell and can lie dormant for extended periods if the pond dries up.
Eggs hatch into nauplius larvae, which consist of head with small tail, but no thorax or true abdomen. The nauplius moults 5 or 6 time, before emerging as a "Copepodid larvae". This stage resemble the adult, but has a simle, unsegmented abdomen and only three pairs of thoracic limbs. After a further five moults, the copepod takes on the adult form. The entier process from hatching to adulthood can take a week to year, depending on the species and environmental condition such as a temprature and nutrition.