Page 98 - Invasive_Species_2013

Mediterranean invasive species factsheet

FISHES

Reproduction Common name: Shrimp scad

Lateral line strongly
curved
identification

Scientific Name:
Alepes djedaba
Picture

Key identifying features

The body is ellipsoid and compressed, up to 40 cm in Brief history black blotch surrounded Tail fin yellow
length (commonly 10–20 cm). The first dorsal fin has 8 by a white spot
spines and is triangular in shape, while the second
dorsal fin (with 1 spine and 22–25 soft rays) is long and
anteriorly elevated. The anal fin has two detached
spines followed by a single spine attached by a
membrane to 18 to 20 soft rays, some of which are turbid waters. It also gathers in large schools above
elevated anteriorly. The last dorsal and anal fin rays are artificial man-made reefs such as harbours and jetties.
elongated. The tail fin is deeply forked. The lateral line Juveniles can be found sheltered among the tentacles
has a series of 39 to 51 scutes (enlarged and thickened of the jellyfish, Rhopilema nomadica or Phyllorhiza
scales), is arched anteriorly and straightens under the punctata. In the Mediterranean it feeds mainly on
first to third dorsal rays. The posterior part of the fishes.
pectoral fins, when folded along the flanks, overlaps the
first scutes. The back is grey with a white belly; the tail
fin and the posterior part of the lateral line are yellow; Reproduction
the upper lobe of the tail fin is dusky to black. In the Indo-Pacific region the presence of maturing
and mature specimens in most months of the year
An obvious distinguishing feature is a black spot
indicates a prolonged spawning season, but in the
present on the upper margin of the operculum (gill
Mediterranean the spawning period is probably
cover), bordered above by a smaller white spot.
shorter.

Field identification signs and habitat
The shrimp scad is a pelagic species inhabiting inshore
waters, where it forms schools near rock reefs, often in

Alepes djedaba. Photo: P. Consoli Rhopilema nomadica. Photo: D. Edelist

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