International Journal of Marine Science, 2017, Vol.7, No.5, 37-50
47
form an integral part of the reproductive process such as nuptial colouration (Dugas and Franssen, 2012). Thus,
the cause of positive allometry in eye diameter requires more insight into the behaviour of
U
.
moluccensis
, how
they adapt in a turbid environment for growth, feeding and reproductive purposes so their life cycle can be
completed.
Morphological adaptations may allow the organism to fully exploit their habitat in a marine ecosystem (Webb,
1984; Wainwright, 1996). However, such adaptations are sensitive to anthropological activities in the habitat such
as the lakes and reservoir (Franssen, 2011), channelization (Scarnecchia, 1988), eutrophication (Seehausen, 2006)
and overfishing (Levin et al., 2006). This may result in an ongoing change of the habitat and thus affecting the life
history characteristics of the population. A few species may react fast through phenotypic plasticity (similar to the
morphological divergence in this study) providing them an intrinsic capacity to survive in a changing environment.
Habitats that change that change, but then remain consistent may cause genetic deviation among fish populations
but morphological differences can provide early cues on their adaptations to the new environment. Though the
present study included only one fish species, our findings and conclusion can be used as a guideline on
determining the shape changes in other Lessepsian species that has migrated through Suez Canal and established
populations in the Mediterranean Sea (Torcu and Mater, 2000).
Our study indicate that the populations of
U
.
moluccensis
in Red Sea and Mediterranean Sea are possibly two
unique fish stocks. Stock assessments of these populations should be carried out independently to provide advice
on fisheries management (Pazhayamadom et al., 2015). Future studies could improve the spatial resolution of
sampling by including more number of locations from both habitats. To reduce observational errors, it is
recommended to obtain samples directly from the habitat through research vessel surveys. This is also important
for conducting stock assessments because illegal, unreported and unregulated commercial fishing activities are
very common in these regions (Tesfamichael and Pitcher, 2007; Öztürk, 2015). Stock identification tools such as
the fatty acid signatures, stable isotope indicators, otolith/ scale morphometry and parasite tagging are extremely
useful for investigating the spatial stock structure of the fish populations (Cadrin et al., 2013). Such techniques
can offer more insight into the dynamics of the fish stock, their migrations, intermixing of individuals and the
environment in which the different life history stages of the organism develop or transform from juvenile to adult
forms.
Authors’ contributions
All authors were equally contributed to the production of this paper.
Acknowledgments
We would like to thank Sergey Bogorodsky for giving us the permission to use the image of
Upeneus moluccensis
collected from
Jizan, Saudi Arabia, Red Sea. Our thanks should also go to Mr. Joacim Näslund, Zoologihurst, Göteborgs Universitet, Göteborg,
Sweden for editing the fish image with Photoshop.
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