Identification of sea bass (Dicentrarchus labrax) nursery areas in the north-western Mediterranean Sea

Abstract

Nursery areas of European sea bass (Dicentrarchus labrax, L.) were investigated from spring 2005 to summer 2006 in areas along the French Mediterranean coast of the Gulf of Lion. Nurseries were identified by the presence of settling individuals of sea bass and young juveniles. These nurseries represent different types of sheltered shallow habitats, both natural such as coastal lagoons, estuaries, and artificial such as marinas. Settlement occurred from April to June during both years. The number of settling individuals varied between sites from just a few individuals to several thousand. In one given site, settlement also varied between 2005 and 2006. The size distribution of sampled individuals revealed that several pulses arrived in each nursery. At this stage, sea bass already exhibited a strong orientation capacity but a limited swimming ability. The magnitude of sea bass settlement in marinas requires better environmental management of such artificial areas.

Behavioural and kinematic components of the fast-start escape response in fish: individual variation and temporal repeatability

“…A complex life cycle, such as that of sea bass, may also be a source of variation in performance. During its life, this species occupies diverse environments where the fish may be subjected to various types and degrees of predation pressure (Quignard, 1984;Dufour et al, 2009). In environments with many predators, it may be beneficial to possess physiological adaptations toward increased burst performance, heightened sensory capabilities and short latencies.…”

“…This species is a temperate perciform that, during its juvenile stages, inhabits shallow coastal waters where it can be subject to significant predation pressure by other fish and birds (Quignard, 1984;Dufour et al, 2009). It is, therefore, an appropriate model on which to investigate the components of the escape performance.…”

An early-life hypoxia event has a long-term impact on protein digestion and growth in European sea bass juvenile

“…European sea bass larvae generally enter shallow coastal areas just after the flexion stage, between 22 and 25 days post-hatching (dph), and they may then be exposed to hypoxic episodes, while their larval development is not totally completed (Dufour et al, 2009). Vanderplancke et al (2015b) reported that early life hypoxia had a negative impact on juvenile growth rate.…”

Fitness difference between cryptic salinity-related phenotypes of sea bass (<em>Dicentrarchus labrax</em>)

“…It is an economically important fish that naturally inhabits marine, lagoon and estuarine environments (e.g. Dufour et al 2009, Vasconcelos et al 2010. Only minor meristic and morphological phenotypic differences necessitating detailed studies to be identified exist in sea bass, and their interaction with fitness is unknown (Barnabé 1973, Corti et al 1996, Loy et al 1999, Bahri-Sfar and Ben Hassine 2009, Costa et al 2010.…”

“…Only minor meristic and morphological phenotypic differences necessitating detailed studies to be identified exist in sea bass, and their interaction with fitness is unknown (Barnabé 1973, Corti et al 1996, Loy et al 1999, Bahri-Sfar and Ben Hassine 2009, Costa et al 2010. Concurrently, sea bass has repeatedly demonstrated different capabilities to acclimate freshwater (FW) in both experimental and natural conditions (Chervinski 1974, Dendrinos and Thorpe 1985, Cataudella et al 1991, Venturini et al 1992, Allegrucci et al 1994, Marino et al 1994, Jensen et al 1998, Eroldogan and Kumlu 2002, Varsamos et al 2002, Nebel et al 2005, Boutet et al 2007, GiffardMena et al 2008, Dufour et al 2009. Sea bass could then be a mixture of cryptic phenotypes with distinct environmental tolerance and fitness regarding salinity, rather than a single unconditional, plastic, euryhaline phenotype as traditionally reported in textbooks (Pickett andPawson 1994, Sánchez Vázquez andMuñoz-Cueto 2014).…”