Mediterranean invasive species factsheet www.iucn-medmis.org Species report Alepes djedaba (Shrimp scad) AFFILIATION FISHES SCIENTIFIC NAME AND COMMON NAME REPORTS Alepes djedaba 4 Key Identifying Features fins, when folded along the flanks, overlaps the first scutes. The back is grey with a white belly; The body is ellipsoid and compressed, up to 40 the tail fin and the posterior part of the lateral cm in length (commonly 10–20 cm). The first line are yellow; the upper lobe of the tail fin is dorsal fin has 8 spines and is triangular in shape, dusky to black. while the second dorsal fin (with 1 spine and 22–25 soft rays) is long and anteriorly elevated. An obvious distinguishing feature is a black spot The anal fin has two detached spines followed by present on the upper margin of the operculum a single spine attached by a membrane to 18 to (gill cover), bordered above by a smaller white 20 soft rays, some of which are elevated spot. anteriorly. The last dorsal and anal fin rays are elongated. The tail fin is deeply forked. The lateral line has a series of 39 to 51 scutes (enlarged and thickened scales), is arched anteriorly and straightens under the first to third dorsal rays. The posterior part of the pectoral 2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 1/5 Mediterranean invasive species factsheet www.iucn-medmis.org Similar Species The most obvious distinguishing feature is the extent of the animal´s oral lobes: in M. leidyi, they span nearly the entire length of the body, while in native ctenophores and in Bolinopsis vitrea, another alien species, they only reach half-way along the body. Moreover, B. vitrea also lacks papillae (warts) on its body. Other species that look similar Identification and Habitat The shrimp scad is a pelagic species inhabiting inshore waters, where it forms schools near rock reefs, often in turbid waters. It also gathers in large schools above artificial man-made reefs such as harbours and jetties. Juveniles can be found sheltered among the tentacles of the jellyfish, Rhopilema nomadica or Phyllorhiza punctata. In the Mediterranean it feeds mainly on fishes. Reproduction In the Indo-Pacific region the presence of maturing and mature specimens in most months of the year indicates a prolonged spawning season, but in the Mediterranean the spawning History and Route of period is probably shorter. Introduction The shrimp scad is widely distributed in the Indo-Pacific. The first individual in the Mediterranean Sea was recorded along the Palestinian coast in 1927 (as Caranx calla). It has subsequently been recorded in the Aegean Sea, Egypt and Greece and is now a very common species in the Levant. 2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 2/5 Mediterranean invasive species factsheet www.iucn-medmis.org Ecological Impacts The shrimp scad can form large schools around natural or artificial reefs. Competition with some native zooplanktivorous species such as Chromis chromis or Sardinella aurita may occur. In addition, many researchers consider that the lower predation pressure on A. djedaba in shallow waters can lead to a greater abundance of juvenile shrimp scads in these habitats. Economic Impacts In the Mediterranean its large schools are caught by beach seine, purse seine and trammel nets, as this fish has some commercial value. Management Options These include a) early eradication of new populations by MPA operators through fishing, and b) maintenance of healthy and abundant assemblages of top predators to encourage natural control through predation. Further Reading Carpenter, K.E., et al. 1997. FAO Species Identification Field Guide for Fishery Purposes. Living marine resources of Kuwait, eastern Saudi Arabia, Bahrain, Qatar, and the United Arab Emirates. http://www.ciesm.org/atlas/Alepesdjedaba.php 2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 3/5 Mediterranean invasive species factsheet www.iucn-medmis.org Map of sightings of the species Alepes djedaba (Shrimp scad) Legend Algae Angiosperm Cnidarians Centre for Mediterranean Molluscs Crustaceans Ascidians Cooperation Combjellies / Fishes Ctenophores More Information: Guide and reports platform for Marine Protected Areas (MPAs) in the Mediterranean. www.iucn-medmis.org 2013-2021 © IUCN Centre for Mediterranean Cooperation. More info: www.iucn-medmis.org Pag. 4/5 Mediterranean invasive species factsheet www.iucn-medmis.org MPAs, Country Date Density Measure Datca-Bozburun, Turkey Before 2013 -- -- Zakynthos, Greece 17/08/2014 -- -- Zakynthos, Greece 30/08/2014 -- -- -- 25/09/2014 -- -- How to cite this tab: Alepes djedaba - Invasive Alien Species Fact Sheet for Mediterranean Network of MPAs. From Online Database MedMIS (IUCN Center for Mediterranean Cooperation, Download date 30/09/2021. More information about this species from: Otero, M., Cebrian, E., Francour, P., Galil, B., Savini, D. 2013. Monitoring Marine Invasive Species in Mediterranean Marine Protected Areas (MPAs): A strategy and practical guide for managers. Malaga, Spain: IUCN. 136 pages www.iucn.org/dbtw-wpd/edocs/2013-008-Es.pdf . Funded by: This collaborative effort is supported by:.