Ecology of the Atlantic black skipjack Euthynnus alletteratus (Osteichthyes: Scombridae) in the western Mediterranean Sea inferred by parasitological analysis

Abstract

Between 2008 and 2011, the head of 150 Euthynnus alletteratus (Osteichthyes: Scombridae) caught inshore off the southeastern Iberian coast (western Mediterranean Sea) were examined for parasites. Two monogeneans, four didymozoid trematodes and four copepods were found. Parasite abundance showed a positive relationship with the annual sea surface temperature, except for Pseudocycnus appendiculatus, but negative with the sea depth (Capsala manteri, Neonematobothrium cf. kawakawa and Caligus bonito). Prevalences and mean abundances differed significantly among sampling areas, except for C. manteri, Oesophagocystis sp. 2 and Ceratocolax euthynni, and sampling years (Melanocystis cf. kawakawa, N.cf. kawakawa, P. appendiculatus and Unicolax collateralis). Results indicate that the parasite abundances of E. alletteratus in the western Mediterranean Sea depend mainly on regional environmental variables, which can show interannual variations. The presence of pelagic parasites, i.e. didymozoids and P. appendiculatus, could indicate that E. alletteratus migrates between inshore and offshore pelagic domains. The different parasite faunas reported in E. alletteratus populations from the western Atlantic Ocean and the Mediterranean Sea appear to point out the geographical host isolation. These results suggest that E. alletteratus inhabiting the western Mediterranean Sea performs inshore-offshore small-scale migrations, and not transoceanic migrations between the western Atlantic Ocean and Mediterranean Sea.

Species diversity and genetic variation of caligids (Copepoda: Siphonostomatoida) infecting the marine fishes of Kerala coast, India

“…Exemptions include C. bonito which infect S. commerson at the inner operculum wall and in E. affinis, its site of attachment is the gill raker. Based on other reports, C. bonito selected multiple sites for its attachment on the host fishes from diverse families (Silas and Ummerkutty 1967;Burnett-Herkes 1974;Knoff et al 1994;Takemoto and Luque 2002;Mele et al 2016;Oktener et al 2017;Nagasawa et al 2018;Hermida et al 2018). All these observations infer that the difference in site preference by caligids possibly depend upon their feeding habit, response of host against the parasites and reproduction strategies.…”

“…On the other side, 23.08% of the caligid species recovered during this study exhibited double host preference, which have also been previously reported for their multiple host selection. The reports include, C. bonito (Silas and Ummerkutty 1967;Knoff et al 1994;Zambrano et al 2003;Dippenaar 2004;Mele et al 2016;Öktener et al, 2017;Nagasawa et al 2018;Hermida et al 2018), C. cybii (Bassett-Smith 1898; Silas and Ummerkutty 1967;Helna et al 2018), C. pelamydis (Boxshall 1974;Somdal and Thomas Schram, 1992;Catalano and Hutson, 2010). H. pyriventris (Hameed 1981;Ho and Kim 2000;Li et al 2000;Purivirojkul and Table 4 Estimates of evolutionary divergence between COI sequences of caligids.…”

Morphological and molecular study of Didymodiclinus marginati n. sp. (Trematoda: Didymozoidae) gill parasite of Epinephelus marginatus from the central and western Mediterranean Sea

“…Until 1985, Didymozoidae included 212 species placed in 81 genera, infecting mainly tropical and subtropical host species, with 23 species occurring in Mediterranean fish (Nikolaeva, 1985). However, in recent years the growing interest for fishery, protection and aquaculture of several fish from the Mediterranean Sea has increased the number of didymozoid species recorded in this region (40 taxa, Mele et al ., 2016; Pérez-del-Olmo et al ., 2016). Didymozoid parasites have been reported on the gills of the wild dusky groupers ( Epinephelus marginatus , Lowe, 1834) (Osteichthyes, Serranidae), one of the largest top predators in the Atlantic and Mediterranean littoral ecosystems.…”

NEW GEOGRAPHIC OCCURRENCE: DIGENEA Lobatozoum multisacculatum (DIDYMOZOIDAE) ON LITTLE TUNNY, Euthynnus alletteratus (SCOMBRIDAE)

“…Within this group, we have the genus Lobatozoum that has, globally, ten species described. In general, their life cycle follows the typical propagation of digeneas, where cephalopods act as intermediate vectors and pelagic fish as definitive hosts (Mele et al, 2016).…”

“…Little tunny, Euthynnus alletteratus (Rafinesque, 1810) is a pelagic and highly migratory fish of the family Scombridae that inhabits the tropical and subtropical coastal waters of both sides of the Atlantic Ocean. There are three main populations of E. alletteratus known in the Atlantic Ocean, located in the center-east, in the southeast and in the west of the Atlantic Ocean (Karakulak et al, 2016;Mele et al, 2016). It is considered an abundant fish species in the Brazilian Northeast coast (Lucena et al, 2004) with very little information regarding its parasitic fauna in this region (Alves & Luque, 2006).…”