الفهرس 
Ribosomal DNA (rDNA).Only 14 pages are availabe for public view
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Abstract
The marine world extends from the ocean to the deepest bed and
from the shore to distant shore. Fishes represent one of the major
controversial components due to their importance both from
economic and human health according to the variety and
difference in their role on several levels:
Fishes are the most numerous and diverse of the major
vertebrate groups. They dominate the waters of the world through
a marvelous variety of morphological, physiological, behavioral
patterns. Their diversity is reflected in the large number of living
species. Moyle et al. (2000) pointed that about 200 new fish species are being described each year and the total may reach
30,000 or more. Fishes represent more than 58% from living
marine ecosystem (Moyle et al., 2000; Rubio-Godoy, 2007).
Fishes are valuable sources of high grade protein and
organic products. Also, fish in terms of good value rank and
mostly superior having less amount of fats, represents the
excellent sources of polyunsaturated fatty acids and more or equal
protein as compared to other fleshes consumed as food by human
beings (Haruna, 2006; Staniskiene et al., 2006; Salawu et al.,2013; Singh, et al., 2013).Fishes occupy a significant position in the socio-economic
status at great sectors of countries by providing the population not
only the nutritious food but also income and employment
opportunities, contribution to economic growth and human
welfare, stimulation growth of a number of subsidiary industries
and contribution to the livelihood of a large section of
economically underprivileged population (Ayyapan
&Krishanan, 2004).
Fish is a renewable source of wealth. Unlike minerals and
other fixed resources which do not have self-generating capacity
to replenish the loss due to natural causes and human exploitation.
Fish has a therapeutic value; from the positive side, modest
doses of sea foods a week, significantly prevent the coronary
heart diseases, also reduces the tendency of blood to clot and
helps lower cholesterol levels in the blood (Shaukat, 2008).
Moreover, from the negative side, several fishes represent a
pathogenic agent for human due to transmission of several
helminths parasites represented by “the anisakid nematodes (particularly Anisakis simplex and Pseudoterranova decipiens),
cestodes of the genus Diphyllobothrium and digenetic trematodes
of the families Heterophyidae, Opisthorchiidae and
Nanophyetidae. Seafood-associated infections by
acanthocephalans are rarely reported in humans” (Adams et al.,1997).Most fish species have at least some direct monetary value,
are part of food webs that support economically important
species, or live in environments whose good health is essential for
the support of fisheries (Shaukat, 2008)
The cultural values of fishes include two wide values;
1) The first one is the scientific values of fish which are obvious
to Ichthyologists who find the study of fish essentially interesting.
2) The second one is the educational values of fish which are also
obvious where fishes are the one group of vertebrates in which it
is really possible to maintain large populations in the laboratory
for observation and experimentation. Many varieties are readily
available for dissection, giving an easy overview of the several types of adaptations possible in vertebrates. Most important is that
they can typically be found in large numbers and diversity in
waters fairly close to most educational institutions, so that many
types of ecological demonstrations can be made. Fish have the
right combination of availability, size and ease of handling tomake them the most desirable group of vertebrates for
comparative classroom studies of ecology, behavior, evolution
and anatomy, and to be very valuable in other areas such asgenetic and physiology as well.