A Review on the Status and Progress in Rearing Copepods for Marine Larviculture. Advantages and Disadvantages. Among Calanoid, Harpacticoid and Cyclopoid Copepods

Resumen

Copepod species of the genera Calanoida, Harpacticoida and Cyclopoida are used in aquaculture as food for marine
larval fish. The calanoids are the most well-known species; most are easily identified as adults and therefore
relatively easy to isolate from the wild. They require phytoplankton as food, and many calanoids are broadcasters
shedding their eggs individually. The eggs sink to the bottom, which, when siphoned, removes both eggs and other
debris. This is usually sufficient to maintain tank hygiene. Many calanoids cannot be kept at high densities and
require therefore large volumes for their culture. Harpacticoids are generally benthic grazers, can be maintained at
very high densities and therefore in much smaller volumes. They require surface area, which can be provided by
placing structures within a tank, although this may complicate the method for cleaning tanks and maintaining tank
hygiene. Harpacticoids do not require phytoplankton and can be fed inert feeds. Both harpacticoids and cyclopoids
have egg sacs and different methods have been developed for harvesting the nauplii from the culture tanks. The
harpacticoids seem particularly difficult to separate from the debris, whereas this seems easier to achieve with
cyclopoids nauplii. The cyclopoids, like the harpacticoids, can be maintained in high densities and seem also
relatively easy to culture.
Pond cultures using fertilisers are also used to produce copepods for rearing fish larvae. The fish are either reared
within the same system or in separate units. Generally, all 3 genera are represented in the zooplankton blooms. The
disadvantages of pond cultures include the risk of parasite transfer, no control over species occurrence and
abundance, and in temperate climates this type of culture is seasonally restricted.