Symbiosis Biology Report

This report presents six species of teleost (bony) fishes selected based on their high commercial importance, distinct behaviour or appearance and occurrence at either or both study locations of this project – the Eastern Mediterranean Sea and the Canary Islands: Albacore tuna (Thunnus alalunga), dorado (dolphinfish; Coryphaena hippurus), swordfish (Xiphias gladius), Atlantic mackerel (Scomber scombrus), Mediterranean horse mackerel (Trachurus mediterraneus) and Greater amberjack (Seriola dumerili).

First, each species is described in terms of its habitat and ecological niche (e.g., preferred temperature or depth range). A short account of their external features and morphology is then provided.

The schooling behaviour of each species is then summarised in the following section of each chapter; some fish in this report are known to aggregate in the vicinity of buoys or other floating objects at sea (such as the THEMO mooring in Israel), in which case the scientific literature on their behaviour may be biased to those structures. In other cases, information on the densities or vertical dynamics are derived from laboratory experiments, fishery records or long-term tagging programmes. As a result, a certain degree of inconsistency between chapters should be considered regarding the available data or their units of measurement.

In the following section of each chapter, an overview of distinct acoustic features such as target strength, swim bladder physiology, or other backscattering factors are presented when applicable.

Finally, swimming types and speeds are provided for either or both, sustained and burst modes, based on empirical laboratory of in situ measurements