@article {4133, title = {The effects of dietary arachidonic acid on Senegalese sole morphogenesis: A synthesis of recent findings}, journal = {Aquaculture}, volume = {432}, year = {2014}, pages = {443 - 452}, abstract = {

Abstract In this study we evaluated the effects of high dietary arachidonic acid (ARA) levels on prostaglandin \{E2\} (PGE2) and \{E3\} (PGE3) production and their effect on two morphogenetic processes occurring during metamorphosis: the establishment of the juvenile pigmentation pattern and eye migration and remodeling of cranial bones. In this sense, Senegalese sole larvae were fed from 2 to 50 days post-hatch (dph) with live prey enriched with an experimental emulsion containing high levels of \{ARA\} (ARA-H; 10.2 and 7.1\% \{TFA\} in enriched rotifer and Artemia, respectively) versus a reference commercial enriching product (Algamac 3050{\textregistered}, AGM; 1.0 and 1.4\% \{TFA\} in enriched rotifer and Artemia, respectively). High dietary \{ARA\} levels did not affect larval growth performance at 50 dph, but significantly induced malpigmentation (81.4 {\textpm} 7.5\%, versus 0.9 {\textpm} 0.3\% in larvae fed the \{AGM\} diet). This malpigmentation was linked to the higher prostaglandin \{E2\} (PGE2) levels observed in pseudo-albino fish as compared to normally pigmented individuals. The \{PGE2\} levels were higher in normally pigmented specimens fed the ARA-H diet than in those fed the \{AGM\} diet. The effects of \{ARA\} on normally pigmented fish fed the \{AGM\} diet and pseudo-albino specimens fed the ARA-H diet were evaluated by means of the density of melanophores and the texture and image segmentation analyses in the dorsal skin of post-metamorphic fish. The skin of pseudo-albino specimens had a more uniform and homogeneous melanophore pattern than normally pigmented fish. Melanophores in pseudo-albino specimens were less abundant and not so aggregated in patches as they were in normally pigmented ones, whereas their shape differed (round vs. dendritic) suggesting their inability to disperse melanin. In addition, fish fed the ARA-H diet presented a higher percentage of cranial deformities (95.1 {\textpm} 1.5\%) than those fed the control diet (1.9 {\textpm} 1.9\%) that was significantly and negatively correlated with the incidence of normally-pigmented animals (R2 = - 0.88, P \< 0.001). Cranial deformities in pseudo-albino fish were associated with an impaired migration of the eye from the ocular side (the right eye), whereas the left eye migrated from the blind side into the ocular side almost normally. The effects of high dietary \{ARA\} levels in the eye migration and cranial bone remodeling processes in post-metamorphic larvae were evaluated by means of the staining of cranial skeletal elements. Pseudo-albino fish showed higher interocular distance and head height than normally pigmented individuals, a different disposition of the eyes with regard to the vertebral column and mouth axes, and a distinct osteological development of some skeletal structures from the neuro- and splanchnocranium, in relation to high dietary \{ARA\} contents and high \{PGE2\} production. These results brought new information about possible nutritional forcing factors and physiological mechanisms of pigmentary disorders and impaired eye migration, which are current major bottlenecks in flatfish aquaculture.

}, keywords = {Skeletal deformities}, issn = {0044-8486}, doi = {http://dx.doi.org/10.1016/j.aquaculture.2014.05.007}, url = {http://www.sciencedirect.com/science/article/pii/S0044848614002233}, author = {Boglino, A and Wishkerman, A and Darias, Maria and de la Iglesia, P and Est{\'e}vez, A and Andree, K B and Gisbert, E} } @article {4144, title = {Senegalese sole (Solea senegalensis) metamorphic larvae are more sensitive to pseudo-albinism induced by high dietary arachidonic acid levels than post-metamorphic larvae}, journal = {Aquaculture}, volume = {433}, year = {2014}, pages = {276 - 287}, abstract = {

Abstract High dietary levels of arachidonic acid (ARA) and its relative proportions with eicosapentaenoic acid (EPA), fed during early larval stages, have been associated with malpigmentation in various flatfish species. This study investigated whether the nutritional induction of pigmentary disorders at larval stages was related to a specific larval period of increased sensitivity to \{ARA\} in Senegalese sole (Solea senegalensis Kaup, 1858). Senegalese sole larvae were fed high dietary \{ARA\} levels during pre- and pro-metamorphosis (2{\textendash}15 dph) and/or post-metamorphosis (15{\textendash}50 dph). Larval tissues reflected the dietary fatty acid composition. Malpigmentations were significantly related to elevated dietary and larval \{ARA\} contents and ARA/EPA ratio. This study reports evidence for a {\textquotedblleft}pigmentation window{\textquotedblright}, with a higher larval sensitivity to dietary \{ARA\} during pre- and pro-metamorphosis than post-metamorphosis. High dietary \{ARA\} fed to larvae during pre-metamorphosis enhanced survival, but did not affect growth nor eye migration. The aspect and density of melanophores in the skin of the ocular side of ARA-induced pseudo-albinos were significantly reduced in comparison to normally pigmented individuals, even more in the pseudo-albino fish fed high dietary \{ARA\} levels during the pre-metamorphic stage. Pseudo-albino fish fed high dietary \{ARA\} levels during post-metamorphosis showed higher concentrations of 2- and 3-series prostaglandins (PGE2 and PGE3) than normally pigmented specimens fed the same diets. An increased sensitivity to ARA-induced malpigmentations has been identified at pre-metamorphosis and early metamorphosis in Senegalese sole. Supplying high dietary \{ARA\} amounts imbalanced the dietary ARA/EPA ratio and disrupted the relative concentrations of derived \{PGE2\} and PGE3, resulting in 20 to 81.7\% pseudo-albino individuals, depending on the dietary treatment. The administration of high levels of dietary \{ARA\} at different developmental stages did not only affect the incidence of animals with pigmentary disorders, but it also affect the melanophore density and skin aspect in normally pigmented and pseudoalbino fish as image segmentation and texture analyses indicated.

}, keywords = {Prostaglandins}, issn = {0044-8486}, doi = {http://dx.doi.org/10.1016/j.aquaculture.2014.06.012}, url = {http://www.sciencedirect.com/science/article/pii/S0044848614003056}, author = {Boglino, A and Wishkerman, A and Darias, Maria and de la Iglesia, P and Andree, K B and Gisbert, E and Est{\'e}vez, A} }