In this paper, 981 reared juveniles of gilthead seabream (Sparus aurata) were analysed, 721 of which were from a commercial hatchery located in Northern Italy (Venice, Italy) and 260 from the Hellenic Center for Marine Research (Crete, Greece). These individuals were from 4 different egg batches, for a total of 10 different lots. Each egg batch was split into two lots after hatching, and reared with two different methodologies: intensive and semi-intensive. All fish were subjected to processing for skeletal anomaly and meristic count analysis. The aims involved: (1) quantitatively and qualitatively analyzing whether differences in skeletal elements arise between siblings and, if so, what they are; (2) investigating if any skeletal bone tissue/ossification is specifically affected by changing environmental rearing conditions; and (3) contributing to the identification of the best practices for gilthead seabream larval rearing in order to lower the deformity rates, without selections. The results obtained in this study highlighted that: i) in all the semi-intensive lots, the bones having intramembranous ossification showed a consistently lower incidence of anomalies; ii) the same clear pattern was not observed in the skeletal elements whose ossification process requires a cartilaginous precursor. It is thus possible to ameliorate the morphological quality (by reducing the incidence of severe skeletal anomalies and the variability in meristic counts of dermal bones) of reared seabream juveniles by lowering the stocking densities (maximum 16 larvae/L) and increasing the volume of the hatchery rearing tanks (minimum 40 m3). Feeding larvae with a wide variety of live (wild) preys seems further to improve juvenile skeletal quality. Additionally, analysis of the morphological quality of juveniles reared under two different semi-intensive conditions, Mesocosm and Large Volumes, highlighted a somewhat greater capacity of Large Volumes to significantly augment the gap with siblings reared in intensive (conventional) modality.

One of the most common drawbacks of artificial life conditions\ud imposed by aquaculture is the quite high presence of skeletal\ud anomalies (SAs) in reared fish, which reduce both functional\ud performances and marketing image ⁄ commercial value of the\ud reared lots. Thus, skeletal malformations and their incidence\ud are one of the most important factors affecting fish farmer s\ud production costs, and several efforts have been due to develop\ud appropriate tools in detecting patterns of co-variation among\ud rearing parameters and fish quality. In this paper we explore\ud the advantages of using Self-Organized Maps (SOMs) when\ud dealing with the analysis of correlations between the pattern of\ud SA presence and rearing parameters in gilthead seabream\ud (Sparus aurata L.), that is a largely reared fish of high\ud commercial value. SOM, which is one of the best known neural\ud networks with unsupervised learning rules, were applied to\ud develop a model of the occurrence of SAs, both in terms of\ud type and quantity, in seabream lots from different rearing\ud approaches (extensive, semi-intensive and intensive). The\ud trained SOMs classified lots according to the variation\ud observed in the different weights of SAs, but also allows the\ud detection of a series of correspondence, namely between: (i) the\ud patter of SAs occurrence and the different rearing approach\ud currently used in seabream aquaculture; and (ii) the total SAs\ud incidence and the variability of meristic counts, represent a\ud completely independent dataset. Mesocosms resulted the best\ud rearing approach to produce wild-like fish, whereas intensive\ud rearing is characterized by the large presence of SA. Globally,\ud results suggested that this approach is reliable to be used for\ud estimate the distance between aquaculture products and the\ud wild-like phenotype used as quality reference

Fish domestication is an evolutionary process arising in captivity through genetic and developmental mechanisms, producing organisms performing more poorly than wild conspecifics in the natural environment. Culture conditions could be suboptimal for fish at particular life cycle stages, presenting environmental disturbances leading to developmental instability. The limited size of captive lots, moreover, can result in the loss of genetic variation, and the resulting homozygosity (as well as hybridization and mutation) could have strong harmful effects on developmental stability. Rainbow trout are the most widely-cultured species in Europe and North America, having been in culture for more than a century. Prolonged artificial selection for desired traits and incidental effects of domestication has led to the development of a 'farmed type'. Fluctuating asymmetry, variations in meristic counts, and skeletal anomalies were examined in several rainbow trout captive and wild clonal lines as indicators of developmental instability. Differences in developmental stability were identified among lines and correlated with different degrees of exposure to captivity. Some relationship between meristic counts and domestication level was found in the present study, with the number of vertebrae and of dorsal pterygiophores and rays being the strongest predictors of the domestication level. However, the occurrence of skeletal anomalies and fluctuating asymmetry were apparently not related to the level of exposure to captivity. The findings of the present study will facilitate the selection of clonal lines with divergent phenotypes for subsequent quantitative trait loci analyses aimed at identifying genome regions linked with morpho-anatomical and physiological adaptive responses to captivity.

The higher mortalities and lower morphological quality of juveniles with a non-inflated swim bladder still remain a major problem in intensive farming. The aim of this study was to investigate a possible relationship between the presence of an abortive swim bladder and skeleton anomalies in gilthead seabream juveniles. A batch of 109 DAH (LS range: 16-47 mm) gilthead seabream was split into two groups on the basis of the presence (group SB)/absence (WSB group) of a normally inflated swim bladder, and processed for skeletal anomaly and meristic count analysis. The presence of pectoral fin anomalies and the absence of any clear-cut and sound relationship between abortive swim bladder and axis deviations characterize the WSB group. Rarer anomalies, such as scoliosis and lordosis in the pre-haemal vertebrae, kyphosis in the haemal vertebrae, pre-haemal and haemal vertebrae body anomalies, exclusively affected the WSB seabream. This result contradicts what is observed in other species, where abortive swim bladder is shown to cause axis deviation. The authors hypothesize that when gilthead seabream larvae with uninflated swim bladder encounter difficulty in maintaining the level in the water column, they have to overuse flapping of the pectoral fins (which appear more deformed in the seabream without swim bladder of this study). This determines a hyper-activity of the pectoral muscles, which then exerts an intense mechanical load on pre-haemal muscles and ossifying vertebrae. Vertebrae and axis anomalies in the pre-haemal and in haemal (in this study still rare in the WSB lot) regions may be later effects, as postural consequences due to the uninflated swim bladder. According to the reviewers' comments, the paper has been revised By Prof. Ian Mc Gilvray.We'll be waiting for any further instruction from your Editorial Office, Sincerely yours, Best regardsOn behalf of all co-authors, Dr. Clara Boglione "Tor Vergata" University of Rome -Biology Department Via della Ricerca Scientifica s.n.c., 00133 Rome (Italy) Cover LetterAccording to the reviewers' comments, the paper has been revised By Prof. Ian Mc Gilvray. 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Relationship between uninflated swim bladder and skeletal anomalies in reared gilthead Response to Reviewers HIGHLIGHTS seabream (Sparus aurata)Loredana Prestinicola, Clara Boglione*, Stefano Cataudella.Department of Biology, University of Rome "Tor Vergata", Via della Ricerca Scientifica, 00133Rome, Italy. *Corresponding author email: boglione@uniroma2.it AbstractThe higher mortalities and lower morphological quality of juveniles with a non-inflated swim bladder still remain a major problem in intensive farming. The aim of this study was to investigate a possible relationship between the presence of an abortive swim bladder and skeleton anomalies in The authors hypothesize that...