Health and reproduction of red mullet, Mullus barbatus, in the western Mediterranean Sea

Abstract

Ferrer-Maza, D.; Muñoz, M.; Lloret, J.; Faliex, E.; Vila, S.; Sasal, P. (2015). Health AbstractThe reproductive and general health of exploited fish stocks is an essential element of sustainable and profitable fisheries. The main purpose of this study is to assess the relationships between reproduction and two important parameters of fish health (parasitism and energy reserves) in female specimens of red mullet, Mullus barbatus, from the western Mediterranean Sea. We present new data for this species on (i) the prevalence and intensity of infection by metazoan parasites; (ii) the total lipid content in muscle and gonads as a measure of condition and (iii) fecundity and egg quality as a measure of their reproductive capacity. The results show that M. barbatus is a batch spawner with an income breeding strategy, an asynchronous development of oocytes and indeterminate fecundity. The results also indicate that the three most abundant and prevalent parasites significantly affect the condition and reproduction of M. barbatus. Specifically, the digenean, Opecoeloides furcatus, causes a reduction in the female's energy reserves while the nematodes, Hysterothylacium fabri and H. aduncum, produce a rise in egg production but impair egg quality. These implications of the relationships between parasitism, fish health and fish reproduction should be taken into consideration in the assessment and management of exploited species.

Links between parasitism, energy reserves and fecundity of European anchovy,Engraulis encrasicolus, in the northwestern Mediterranean Sea

“…The values of fecundity reported in the present study are also coherent with other studies carried out with the European anchovy in the Adriatic Sea ( Casavola et al , 1996 ) or in the northeast Atlantic Ocean ( Sanz and Uriarte, 1989 ; Motos, 1996 ). The batch fecundity was positively related to total length, which means that larger individuals have a higher reproductive capacity than smaller ones, as is commonly the case with several northwestern Mediterranean commercial fish species ( Muñoz et al , 2005 ; Ferrer-Maza et al , 2014 , 2015 ; Villegas-Hernández et al , 2014 , 2015a , b ). In the present study, the size of all the immature anchovy specimens we examined exceeded 9 cm, which is currently the minimal landing size for anchovy in the Mediterranean Sea.…”

“… Barber and Svensson 2003 ; Bagamian et al , 2004 ; Bean and Bonner 2009 ). However, only a few studies have analysed the relationships between parasitism, energy reserves and reproduction in commercially exploited fish species in the Mediterranean ( Ferrer-Maza et al , 2015 , 2014 ). There is, to our knowledge, only one other study concerning the European anchovy, carried out in the Black Sea, which has looked into the effects of parasites (in this case, nematodes) on the lipid composition of the European anchovy ( Shchepkina, 1985 ).…”

Fatty acid composition and parasitism of European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) populations in the northern Catalan Sea in the context of changing environmental conditions

“…Along with food availability and reproduction, parasitism has also been identified as a factor affecting the body condition of several fish species in the Mediterranean (e.g. Lloret et al , 2012 ; Ferrer-Maza et al , 2014 , 2015 , 2016 ; Serrat et al , 2019 ). However, to our knowledge, few studies have looked into the effects of parasites on the lipid content of small pelagic fish in the Mediterranean, and those that exist have yielded conflicting results.…”

Phylogenetic Affinity of Genolopa (Digenea: Monorchiidae) with Descriptions of Two New Species

“…We made several attempts to collect Lasiotocus mulli (Stossich, 1883) Odhner, 1911 (type-species) but were unsuccessful. Ferrer-Maza et al [60] represents the most recent report of L. mulli collected in the Mediterranean Sea, but personal communication with the primary author revealed that the prevalence of L. mulli was very low in her study. Over 300 specimens of the definitive host were examined, and only 5 specimens of L. mulli were found.…”