This study focused on the anatomy and ontogeny of saddleback syndrome (SBS) in reared European sea bass. The abnormality was detected at an unusually high frequency (12–94%) during a routine quality ...control in a commercial hatchery. Anatomically the abnormality was mainly characterized by the loss of 1–5 hard spines and severe abnormalities of the proximal pterygiophores (anterior dorsal fin), size reduction of a few lepidotrichia, missing lepidotrichia and/or lepidotrichia of poor ossification (posterior dorsal fin). SBS was significantly correlated with abnormalities of the anal and pelvic fins in all the examined populations. Moreover, in juvenile fish, SBS was significantly correlated with an abnormal lack of sectors of the lateral line. The examination of early larval samples revealed that SBS was ontogenetically associated with severe abnormalities of the primordial marginal finfold, which developed at the flexion stage (ca 8.5–11.0 mm SL). Histologically, these abnormalities were associated with extensive epidermal erosion. The results are discussed in respect of the critical ontogenetic period and the possible causative factors of SBS in European sea bass. It is suggested that causative factors acted during a wide ontogenetic period including flexion and metamorphosis phases.
Abstract
This study focused on the anatomy and ontogeny of saddleback syndrome (
SBS
) in reared European sea bass. The abnormality was detected at an unusually high frequency (12–94%) during a ...routine quality control in a commercial hatchery. Anatomically the abnormality was mainly characterized by the loss of 1–5 hard spines and severe abnormalities of the proximal pterygiophores (anterior dorsal fin), size reduction of a few lepidotrichia, missing lepidotrichia and/or lepidotrichia of poor ossification (posterior dorsal fin).
SBS
was significantly correlated with abnormalities of the anal and pelvic fins in all the examined populations. Moreover, in juvenile fish,
SBS
was significantly correlated with an abnormal lack of sectors of the lateral line. The examination of early larval samples revealed that
SBS
was ontogenetically associated with severe abnormalities of the primordial marginal finfold, which developed at the flexion stage (ca 8.5–11.0 mm
SL
). Histologically, these abnormalities were associated with extensive epidermal erosion. The results are discussed in respect of the critical ontogenetic period and the possible causative factors of
SBS
in European sea bass. It is suggested that causative factors acted during a wide ontogenetic period including flexion and metamorphosis phases.
The Eudoxos Project Andrikopoulos, N.; Apostolakis, M.; Savvas, S. ...
Technology Enhanced Learning
Book Chapter
The Eudoxos project aims at using the possibilities the Internet offers in order to transform the classroom into a research laboratory. The project studies the applicability of the emerging ...technology in the school sector and provides a platform that allows the students to use the Robotic Telescopes of the Eudoxos National Observatory for Education and Research in the framework of their school curriculum. The robotic telescopes are installed in the Eudoxos National Observatory for Education and Research on the Ainos mountain of Kefallonia Island (Ionian Sea), Greece, performing night sky as well as solar observations.
Cleaner fish species have gained great importance in the control of sea lice, among them, lumpfish (Cyclopterus lumpus) has become one of the most popular. Lumpfish life cycle has been closed, and ...hatchery reproduction is now possible, however, current production is reliant on wild caught broodstock to meet the increasing demand. Selective breeding practices are called to play an important role in the successful breeding of most aquaculture species, including lumpfish.
In this study we analysed a lumpfish population for the identification of genomic markers linked to production traits. Sequencing of RAD libraries allowed us to identify, 7193 informative markers within the sampled individuals. Genome wide association analysis for sex, weight, condition factor and standard length was performed. One single major QTL region was identified for sex, while nine QTL regions were detected for weight, and three QTL regions for standard length.
A total of 177 SNP markers of interest (from QTL regions) and 399 high Fst SNP markers were combined in a low-density panel, useful to obtain relevant genetic information from lumpfish populations. Moreover, a robust combined subset of 29 SNP markers (10 associated to sex, 14 to weight and 18 to standard length) provided over 90% accuracy in predicting the animal's phenotype by machine learning. Overall, our findings provide significant insights into the genetic control of important traits in lumpfish and deliver important genomic resources that will facilitate the establishment of selective breeding programmes in lumpfish.
•SNP markers were developed for the lumpfish Cyclopterus lumpus.•Total 7193 SNPs discovered, encompassing the 25 chromosomes of genome.•Sex-associated and growth-related SNPs are reported.•A set of 29 robust SNP markers provids over 90% accuracy in phenotype predicting.
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