Image of the scientific team in the MEDITS06-11 (GSA06) trawl survey conducted in May and June 2011. Monthly variation in the relative frequency of ovarian developmental stages in hake (January 2010 to March 2012). Map of the Western Mediterranean Sea showing the locations where Mullus barbatus was caught (FAO-GFCM Geographical Subarea GSA-06, Northern Spain).
Quarterly changes in the relative frequency of ovarian developmental stages in Mullus barbatus (January 2010 to May 2012). Analysis of variance results for the response variables [lipid musculo-somatic natural logarithm (ILM) index, lipid gonadosomatic index (ILG) and relative fertility of the series (FBrel)] and the effects of explanatory variables [year, total length (LT), breadth and depth of cover ]. Parasitism, status and reproduction of hake (Merluccius merluccius) in the northwestern Mediterranean Sea.
Regarding red mullet, the samples were collected along the western coast of the Spanish Mediterranean (Fig. II.1 in the results section). Image of the scientific staff of the MEDITS06-11 (GSA06) trawl survey conducted in May-June 2011. The lipids in the gonads were considered as an indicator of the energy reserves used (or invested) in the reproductive process.
Bray (Natural History Museum, London) who kindly helped us identify the digeneans.
European hake (Merluccius merluccius)
The main aim of this study is to assess the relationships between metazoan parasites and the condition and reproduction of European cod in the Northwestern Mediterranean Sea. Furthermore, the prevalence of anisakid larvae in internal organs is clearly higher than in muscle tissue (Valero et al. 2006). Average intensity was calculated as the average number of parasites of a particular species found in infected hosts.
The intensity of anisakid infection in the digestive tract was also positively correlated with ODW and LGSI, although LGSI presented a negative correlation with the total number of ectoparasite species. Furthermore, during the spawning ability phase, the presence of anisacid nematodes in the mesenteries was associated with high atresia intensity values. A joint analysis of energy stores in the liver and gonads showed fluctuations in the amount of lipids between tissues according to the stage of ovarian development.
The values of fecundity agree with previous studies carried out in the Mediterranean (Recasens et al. 2008), in the North Atlantic (Murua et al. Incidence and relative intensity of atresia follow the expected values for species with undetermined fecundity, such as the hake population in the North Atlantic (Murua & Motos 2006).
Red mullet (Mullus barbatus)
These implications of the relationships between parasitism, fish health and fish reproduction must be taken into account in the assessment and. This species is an important component of the Mediterranean demersal resources exploited by bottom trawling and small-scale fisheries (Fischer et al. As described by Bush et al. 1997), parasite prevalence (PP) was calculated as the proportion of fish infected is with a particular parasite species and the individual intensity of the infection as the number of individuals of a particular species in a single infected host.
The gonado-somatic index (IG), which is the relationship between gonadal mass (MG) and intestinal mass (ME) of the females, was calculated as. To describe the developmental stage of the oocytes, we used the terminology used by (Lowerre-Barbieri et al. 2011): primary growth (PG), cortical alveolar (CA), vitellogenesis (VIT1 and VIT2), maturation (OM) , hydrated oocytes (H) and atresia. The mean dry mass of oocytes (MDO) was calculated by dividing the dry mass of the sample by the number of oocytes in the sample.
No significant differences during different ovarian development phases were found in the prevalence of the other parasites. Box plots of the stage-specific oocyte diameter belonging to 10 randomly selected Mullus barbatus specimens in spawning-competent phase. All females in the spawning-competent phase (with PG, CA, VIT1, VIT2, OM and H oocytes present) appeared in the second and third trimesters.
Oocyte diameter and frequency distribution (over 200 µm) shown in most Mullus barbatus females with hydrated oocytes. We found no significant effects caused by the remaining analyzed parasites, i.e. The results of the histological observation of the ovaries, together with the analysis of the gonadosomatic index, show that the spawning period of M.
The investigation of the relationships between parasitism, fitness and reproduction in fish has highlighted that spawning stage specimens of M. barbatus infected by the digenean Opecoeloides furcatus showed a lower musculosomatic lipid index than uninfected specimens. This result could indicate a negative effect of O. furcatus on the energy reserves of M. barbatus, especially in the spawning season, when fish divide their energy expenditure between maintaining their fitness and reproduction. Regarding the latter, parasitism appears to affect reproduction by causing quantitative and qualitative changes in spawning.
European anchovy (Engraulis encrasicolus)
Lipid muscle somatic index (ILM) was calculated as ILM = 100 ABSM ME-1, where ABSM is the absolute lipid content of the muscle, which was obtained by multiplying the lipid content (% wet weight) by the wet weight of the muscle. Implications for stock health in a hypothetical scenario of an increase in the minimum landing size (MLS) for European anchovy in the Mediterranean Sea. Regarding fish fitness, most of the significant results indicate a negative effect of parasitism on the energy reserves of individuals.
Jijjiirama waqtii nyaata mullets diimaa (Mullus barbatus L.) kaaba Sisilii basin keessatti. Nyaata hake Awurooppaa Merluccius merluccius (Qurxummii: Merluciidae) kan dhiha Meditiraaniyaanii (Løvefugten) keessatti argamu. Nyaataa fi amala nyaataa mullet diimaa, Mullus barbatus (Actinopterygii: Perciformes: Mullidae), qarqara galaanaa kaaba Tuuniziyaa (giddugaleessa Meditiraaniyaanii) irraa fagaatee argama.
Maturity and fecundity of a series of European hake (Merluccius merluccius, Linnaeus, 1758) in the eastern mid-Atlantic. Status and energy reserves of Atlantic cod (Gadus morhua) during the collapse of the northern bay of Sv. Population size structure, growth and reproduction of the European anchovy (Engraulis encrasicolus, L.) in the Lesina Lagoon (Southwestern Adriatic Sea, Italy).
Climate modulation of fish populations: the role of the Western Mediterranean Oscillation (WeMO) in the production of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the northwestern Mediterranean. Reproductive cycle of the European anchovy Engraulis encrasicolus (Linnaeus, 1758) (Clupeiformes Engraulidae) in Skikda Bay (East Coast of Algeria). Reproductive strategy and spawning activity of the European hake Merluccius merluccius (L.) in the Bay of Biscay.
Reproductive mode and fecundity of the European cod (Merluccius merluccius L.) group in the Bay of Biscay. Spawning pattern and fecundity of the European cod group (Merluccius merluccius (Linnaeus, 1758)) in the western Mediterranean. Climate-driven changes in life-history traits of the bastard snore Pomadasys incisus (Teleostei: . Haemulidae) in the northwestern Mediterranean.
Reproduction, condition and abundance of Mediterranean bluefish (Pomatomus saltatrix) in relation to ocean warming. In this appendix, the images of the identified metazoan parasites found in the three species studied are shown.
