Kamis, 11 September 2008

AGE FISH

AGE FISH.

In Biology Fishery of knowledge concerning composition old age in fish community or population a[n territorial water play a part importantly, especially if attributed to production will be able to seen to sliver its bearing with management of fish as resource from a[n territorial water. fish in a[n territorial water as a(n) community member or population non consisting of one age group.


To facilitate congeniality hereinafter, hence weared as base [is] one just population, except there [is] other statement which show or community of multiple species. One population which have succeeded to perform [a] breeder yield a large amount of fish children base on fecundity, efficacy of and breeder of mortalitas of fish children. Rest of fish children which grow and succeed tired life [of] size measure able to diekspliotasi named [by] recruitmen.


Situation of fish amount of each class in existing population composition in certain to territorial water at one time base on rekruitmen that happened per annum and amount of missing fish of that territorial water [is] caused by to be taken by human being or exploited or because that fish [of] death naturally. Fluctuation of[is level of the amount of fish of each age group which forming that population can give cycle history [of] fish life from each its group or cohort.

Given the the fish age and its existing amount composition and succeed life, we earn to know efficacy or failure of certain fish reproduction in the year, for example effect of endless summer, including abundant exploitation or [do] not [at] certain yrs.. Situation that way can be traced to [pass/through] research of structure or composition old age with its member at the (time) of is certain, and earn [is] also weared to anticipate fishery product at the (time) of coming.


Differ from most other vertebrate faction like mammal and bird, most fish have capacities continue growth during life when available food and condition enough better although [at] old growth of just scanty fish. Equally fish don't have certain limit to limit growth ( growth undeterminate), [do] not like mammal and bird will desist to grow when reaching adult size measure that is maturity of sexual ( growth determinate).

long lived Fish there [is] tendency have [common/ public] marking as follows: by phylogenetis the including into primitive fish faction, movement of it is slowgoing, as elementary dweller or territorial water of skin-deep, having appliance respiration of addition, supple to extreme change [of] oxygen, and temperature of salinitas. For example for example fish of sturgeon and of cucut. But there [is] long lived goldfish also. Some short-lived fish don't have the nature of like above mentioned for example fish of salmon.


From death of fish naturally difficult to determine its age. But from research note, for example fish of sturgeon, there [is] which old age 152 year. fish of Sturgeon which [is] looked after in aquarium [in] Amsterdam there [is] tired [of] age 69 year and [in] tired Frankfurt [of] age 38 year. Also many aquarium fish have been looked after to exceed age 20 year.
source : M. Ichsan Effendie, 1997.

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