International Journal of Marine Science, 2017, Vol.7, No.32, 308-315
313
3 Discussion
The present report is the first record of coloration anomalies in
E. stoliczkae
,
P. playfairi
and
P. sordidus
.
According to Craig et al. (2011),
E. stoliczkae
is not reported from the Arabian Gulf area. As in the other Gulf
States, fish commodities imported from abroad and offered for sale in the local fish market. In the case of
E.
stoliczkae
, it is usually imported from Sultanate of Oman.
The pattern of the color aberration case reported for
E. stoliczkae
by Jawad and Al-Kharusi (2013) from Oman
differs completely from the present cases. The specimens examined in this study showed a severe case of color
aberration due to the large are affected. The color of the unaffected areas was less visible, while in the case of
Jawad and Al-Kharusi (2013) the unaffected areas kept their normal grade of coloration. Unlike the case of Jawad
and Al-Kharusi (2013), the pale patch that covered the body of the fish in the present study had no patch of normal
coloration. Variation in color aberration between different sites of the fish body might be due to the causes given
by Roulin and Ducrest (2011). They found that controlling the genes of the melanocortin system or of their
products will have significant effects on a set of characters. Slominski et al. (2000), found that the level of activity
of the different melanocortins is correlated across tissues. Other studies indicated that with the aid of
neuroendocrine communication, the activity of the melanocortin system can be locally regulated and coordinated
(Slominski and Wortsman, 2000) and such manipulation could vary between tissues of the fish body (Hoglund et
al., 2000).
Ambicoloration is frequently accompanied by some morphological variation (Díaz de Astarloa, 1995; 1998;
Jawad, 2014). No noticeable variation on morphological or meristic characters was found for the ambicolored
epinephelid or haemulids species studied.
In fishes, aberration in normal coloration can happened due to several reasons and they are depend on the type of
pigmentation disorder. Studies showed that such abnormalities in the color might be as results of wounds or bites
(Moe, 1963; Colman, 1972); might have genetic bases (Hernandez and Sinovcic, 1987); might be due to local
tissue environment (Seikai, 1992; Seikai and Matsumoto, 1994); might related to diet deficiency (Kanazawa,
1993); increasing water temperature during the larval development might has direct effect on development of skin
pigmentation (Aritaki and Seikai, 2004), and disorder in the level of the thyroid hormone might be behind this
abnormality (Okada, 2005). Other factor such as the cellular interaction might also contribute to such aberration.
The cellular interaction interferes with the control of the pigment cell arrangements on the fish body, which in turn
cause malpigmentation in perciform fishes (Lueken et al., 1973). Diseases such as scuticociliatosis and other
ciliatosis are believed the cause of the aberration in sea bass for example (FAO, 2005-2012). In
Epinephelus
coioides
,
it found that the parasitic infestations by
Cryptobia
sp,
Scyphidia
sp.
Vorticella
sp.
Dactylogyrus
sp.
Neobenedenia girellae
,
and Gnathia
sp. Can cause loss of pigments from the skin (FAO, 2010-2012). Deficiencies
in vitamins like C and E could bring color aberration due to loss (Lovell, 1973). In addition, fat level
discrepancies in the food content could also lead to loss of pigments
in Chinook salmon (FAO, 1980). All the
above causes mentioned above could be behind the loss of pigments
cases described in the present study. Clearly,
a thorough investigation is required to define the cause
of depigmentation perceived here, but the present records
are nevertheless significant owing to the rarity of the
phenomenon in wild populations.
Authors’ contributions
Both authors have contributed equally toward the publication of this paper.
Acknowledgments
We would like to thank the Ministry of Agriculture, Fish Welfare Branch, Jubail Province, Saudi Arabia for giving us the opportunity
to examine and study the deformed fish specimens. Our thanks are also due to Sergey Bogorodsky of Station of Naturalists, Omsk,
Russia and Ronald Fricke of Staatliches Museum für Naturkunde, Rosenstein, Germany, for identification of the species.
References
Aritaki M., and Seikai T.,
2004, Temperature effects on early development and occurrence of metamorphosis-related morphological abnormalities in
hatchery-reared brown sole
Pseudopleuronectes herzensteini
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