Nova maksimalna dužina pauka crnca, Trachinus araneus Cuvier, 1829 (Perciformes: Trachinidae) iz zapadnog Mediterana, zaljev Oran

On the 29th of October 2018, one specimen of the spotted weever, Trachinus araneus measuring 47.3 cm in total length and weighting 968 g was captured by trammel net operating in Oran Bay (Kristel fishery) Western Algerian coast at 100 m depth. Up to date, this length is a new record of maximum length reached for this trachinid in the Mediterranean basin.Dana 29. listopada 2018. g. ulovljen je jedan primjerak pauka crnca, Trachinus araneus Cuvier, čija je totalna dužina iznosila 47,3 cm, a masa 968 grama. Primjerak je ulovljen na dubini od 100 m u zaljevu Oran (zapadna alžirska obala). Ovo je dosada najveća zabilježena dužina za ovu vrstu u mediteranskom bazenu

Age, growth and mortality of the common carp (Cyprinus carpio) population in Merdja Sidi Abed Dam, Algeria

We tried to estimate age, growth parameters, condition factor, length-weight relationship and mortality rates (Z, M, and F) of the common carp in Merdja Sidi Abed dam. Cyprinus carpio specimens were captured by long line between April and June 2013 in Merdjea Sidi abed. 220 individuals were collected and weights ranged between 265.5 and 620.3 g while the total length ranged between 26.3 and 35.6 cm. Length-converted catch curve was used to estimate total annual instantaneous mortality rates (Z), natural mortality was calculated using Pauly formula [ln(M) = -0.0152 - 0.279 ln(L∞) + 0.6543 ln(K) + 0.463 ln(T)]. Recruitment patterns were determined from the routine implemented in FISAT II. For all individuals (n = 220) of the common carp, the relationship between total length and body weight was: W = 0.0384 L2.70 (r2 = 0.906) for females and W = 0.0467 L2.653 (r2 = 0.976) for males a minor allometry was found for this species, mean condition factor K was estimated at 1.41. The maximum value of recruitment was recorded in March-April period with 19.56 and 15.20% respectively. The Battacharya method was used to estimate age of individuals that was comprised between 1 and years 3. The equation of Von Bertalanffy growth was: L = 36.75 [1-e-0.46 (t + 0.33)] for all the population. Total mortality (Z), natural mortality (M) and fishing mortality (F) were as follows: Z = 1.08, M = 0.82, F = 0.26 yr-1 while exploitation ratio (E) was evaluated at 0.24 indicating an under exploitation of this local resource

Population dynamic parameters of the red mullet Mullus barbatus (Mullidae) in the Arzew Gulf, Algeria

Population dynamic parameters of red mullet, Mullus barbatus (n=592) caught by trawlers operating in Arzew Gulf (Algeria) in the western Mediterranean were studied. Samples were collected between February 2013 and January 2014. Females ranged from 10.9-23.2 cm in total length and 12-149.2 g in weight whereas males length was comprised between 12.6 and 19.7 cm and weight between 21.3 and 99.9 g. The relationship between length and weight was W=0.00167L2.842 (r²=0.850). Growth parameters of the von Bertalanffy equation were: L∞=20.89 cm, K=0.66 year-1, t0=-0.143 year for males, while for females: L∞=250.9 cm, K=0.6 year-1, t0=-0.015 year. Estimates of total (Z), natural (M) and fishing (F) mortalities were: 1.58, 0.8 and 0.79, respectively and the estimated exploitation ratio 0.5 indicating that the resource is being exploited at its limit in this area. The virtual population analysis of M. barbatus by VIT software showed that the number of recruits per year was estimated at 4447304.6 individuals, balanced total biomass was estimated at 168 486 tons, the gains are represented by recruitment 51.71 tons (30.69%) and growth 116.76 tons (69.31%), losses are represented by natural mortality 98.48 tons (58.45%) and fishing mortality 70 tons (41.55%). The current yield per recruit was estimated to Y/R=15.74 g and maximum sustainable yield can be reached by increasing the current fishing effort to stabilize it at MSY=17.91 g

Weight-length relationships of seven fish species (Teleostei: Sparidae, Mullidae, Carangidae) of Western Mediterranean Sea (Oran Bay, Algeria)

No information currently exists on the weight-length relationships of Sparidae: Axillary seabream Pagellus acarne (Risso, 1827), bogue Boops boops (Linnaeus, 1758); Mullidae: Red mullet Mullus barbatus (Linnaeus, 1758), surmulet Mullus surmuletus (Linnaeus, 1758) and Carangidae: Atlantic horse mackerel Trachurus trachurus (Linnaeus,1758), Mediterranean horse mackerel Trachurus mediterraneus (Steindachner 1863), Blue jack mackerel Trachurus picturatus (Bowdich 1825), seven commercial fish species of Oran Bay in Western Mediterranean Sea. Data are presented for the first time for that region of the Mediterranean Sea to contribute and help comparative growth studies. Samples were collected from commercial catches at Oran Bay fisheries in Algeria. The values of the slope b in the lengthweight relationship, W=aLb ranged from 2.841 to 3.296. The coefficients of correlation r2 were comprised between 0.85 and 0.97. “a” and “b” parameters were compared with other fishing sites for the same fish species with Froese plot [Log a=ƒ(b)]

Population dynamic parameters of the red mullet Mullus barbatus (Mullidae) in the Arzew Gulf, Algeria

Population dynamic parameters of red mullet, Mullus barbatus (n=592) caught by trawlers operating in Arzew Gulf (Algeria) in the western Mediterranean were studied. Samples were collected between February 2013 and January 2014. Females ranged from 10.9-23.2 cm in total length and 12-149.2 g in weight whereas males length was comprised between 12.6 and 19.7 cm and weight between 21.3 and 99.9 g. The relationship between length and weight was W=0.00167L2.842 (r²=0.850). Growth parameters of the von Bertalanffy equation were: L∞=20.89 cm, K=0.66 year-1, t0=-0.143 year for males, while for females: L∞=250.9 cm, K=0.6 year-1, t0=-0.015 year. Estimates of total (Z), natural (M) and fishing (F) mortalities were: 1.58, 0.8 and 0.79, respectively and the estimated exploitation ratio 0.5 indicating that the resource is being exploited at its limit in this area. The virtual population analysis of M. barbatus by VIT software showed that the number of recruits per year was estimated at 4447304.6 individuals, balanced total biomass was estimated at 168 486 tons, the gains are represented by recruitment 51.71 tons (30.69%) and growth 116.76 tons (69.31%), losses are represented by natural mortality 98.48 tons (58.45%) and fishing mortality 70 tons (41.55%). The current yield per recruit was estimated to Y/R=15.74 g and maximum sustainable yield can be reached by increasing the current fishing effort to stabilize it at MSY=17.91 g

Physico-Chemical Quality and Metallic Pollution Levels in Wastewater Discharges from Mostaganem (Algerian West Coasts).

The present study aimed to evaluate the physico-chemical quality (temperature, salinity, pH, O2, and SS) of Mosatganem nearshore waters, and the level of metal contamination (Zn, Pb and Cd) in urban and industrial wastewaters of Mostaganem city. For this, a sampling program was carried out monthly during one year (December 2009-November 2010). The temperature of the urban and industrial water discharged fluctuated between 18.5 and 17.

Reproductive biology of Pagellus acarne (Risso, 1927) (Teleostei: Sparidae) off western Algerian waters (Western Mediterranean)

The reproduction of Pagellus acarne caught in Oran Bay was studied. The samples used were sorted monthly from commercial catches of coastal trawlers operating in this area from April 2008 to July 2009. The overall sex ratio was in favor of females 1:1.27 and length frequency distribution according to sex revealed that the females were highly representative beyond 20.5 cm of total length presuming a sexual inversion already described for this sparidae. The estimated lengths at maturity (Lm) were 12.8 cm for females and 16.0 cm for males. Two spawning periods were made out by the follow-up of the gonado and hepato somatic indexes: a spring period from April to June with a peak in May and an autumnal period, between November and January with a peak in December. The closed season in Oran Bay extends from 1st May to 31th August, which is to our opinion insufficient to safeguard the renewal of the resource and its spawning stock

On the fecundity of the seabream, Pagellus acarne (Risso, 1827) of the western Mediterranean Sea, Algerian coasts

The fecundity of the Seabream from the western Mediterranean (Algerian coast) was assessed by the volumetric method using 22 ovaries from females between 169 and 263 mm total length (206.62 ± 19.93). Estimates of total potential annual fecundity varied between 19875 and 49125 oocytes per female (29448.86 ± 8198.12). Relationships between total potential fecundity (F) and total length (Lt), total weight (Wt), gonad weight (Wg) were established using the multiplicative regression model and a significant correlation was found (ANOVA: P‹0.01)

Fecundity of the blotched picarel, Spicara maena (Linnaeus, 1758) from Oran Bay (Western Mediterranean Sea)

The fecundity of the blotched picarel Spicara maena from the western Mediterranean (Oran Bay) was assessed by the volumetric method. Total length (TL) of studied females varied between 91 and 140 mm (mean ± SD: 111.9 ± 10.6 mm). Estimates of total potential annual fecundity varied from 16,750 to 28,125 oocytes per individual (mean ± SD: 21,404.7± 2,698.8). Relationships between total potential fecundity (F) and TL, total weight, gonad weight were established using the multiplicative regression model and a high significant correlation was found in all the cases