Morphometry and diet of Mormyrus rume in the Lekki lagoon,Nigeria

Aspects of the biology of Mormyrus rume (Cuvier and Valenciennes) in Lekki lagoon were investigated. This included the length-weight relationship, condition factor, food and feeding habits and the fecundity of the fish species. The major fishing methods employed for collecting the 225 specimens were castnetting and setnetting. The total lengths ranged from 15.0 to 24.9 cm while the standard lengths ranged from 13.0 to 23.0 cm. The body weights also ranged from 26.2 to 99.3 g. The fish exhibited isometric growth in the lagoon. The mean condition factor obtained was 1.20. The condition factor generally decreased with increase in individual sizes. The major food items were detritus and plant parts. The population of males was significantly higher than the females. The gonadosomatic index showed that M. rume in the Lekki Lagoon uses an average of 7.89% of its body weight in egg production. Fecundity ranged from 741 to 6000 eggs with an average of 2991 eggs per female.     

Life history of the Western Crested Loach <Emphasis Type="Italic">Paracobitis malapterura</Emphasis> in the Zarrin-Gol River,East of the Elburz mountains (Northern Iran)

A total of 370 specimens of Paracobitis malapterura in the Zarrin-Gol River (east of the Elburz Mts, Iran) were caught by regular monthly collection throughout one year from November 2006 to October 2007. The specimens were then examined for age and growth, reproduction and feeding attributes. Based on otolith readings the maximum ages of the population observed were 3⁺ years for males and 4⁺ years for females. The specimens ranged in size from 38 to 130 mm total length, weighing from 0.68 to 30.55 g total weight. Length-weight relationship was estimated as W = 0.020L ^2.62 for males, W = 0.002L ^3.81 for females and W = 0.008L ^3.08 for the population. Sex ratio was 1: 1.27 in favor of females. The Gonadosomatic index indicated that reproduction of the loach in the river occurred around April–May, with the highest average value of 1.48 for males and of 5.36 for females in May. The absolute fecundity ranged between 92–1180 eggs with a mean of 456.31 eggs. Diameter of oocytes ranged from 0.11 to 2.80 mm with a mean value of 0.95 mm. The absolute fecundity and oocyte diameter to fish size (length and weight) and age were not significantly correlated. Plecoptera and Trichoptera dominated the diet contents composing 72.43% and 20.80% of total frequency of food items, respectively.     

Trade-offs in the life history and energy budget of the parthenogenetic collembolan Folsomia candida (Willem)

Three clones of Folsomia candida from different locations in Europe were compared in four experiments investigating genetic and phenotypic correlations between life-history traits. The first three experiments focused on the effects of food type, clone and temperature on traits associated with the first clutch. Differences in clutch size between clones and treatments were almost completely attributable to body size. Clones differed in length of the juvenile period, but the difference decreased at low temperatures. Age and weight at first reproduction were negatively correlated in the food type experiment and positively correlated in the temperature experiment, an often-encountered result for which no general explanation is as yet available. In the temperature experiment egg size variation was considerable, and was highest at low temperatures. The fourth experiment, with two clones at two feeding levels, aimed at finding trade-offs, in particular between reproduction and survival. It was hypothesized that higher fecundity led to increased scenescence through a higher metabolic rate. The trade-off was clearly present among the clones: one combined fast growth, late reproduction and high lifetime fecundity with lower survival, while in the other the relation between these traits was opposite. The proposed mechanism, however, was not confirmed, as no difference in metabolic rate was found. The effect of food level was too small to result in significant differences in the life-history traits in either of the clones.     

Reproductive biology, length-weight relationship and relative condition of pond raised Tilapia zilli (Gervais)

In 'runted' populations of Tilapia zilli positive correlations were found between maturation stages and the following: gonadosomatic index, gonad weight, fish weight and fish length. The minimum size at maturity was 9·0 cm in males and 11·0 cm in females. The mean fecundity in the 'stunted' females was 2359 eggs and it increased with length ( L ) weight (HO and depth ( D ) of the fish. There was, however, no correlation between fecundity and egg size. The results indicated that growth in this 'stunted' T. zilli population was not isometric. The relative condition factor ( Kn ) which approached one indicates good condition.     

Ecological consequences of food partitioning for the fish population structure in a eutrophic lake

In the highly eutrophic lake, Frederiksborg Slotssø, the diet composition of the bream (Abramis brama L.) and roach (Rutilus rutilus L.) populations was examined during three periods with different food availability. The length range of bream and roach was 9–34 cm (TL) and 5–18 cm (TL), respectively. The relative food composition was examined for 2 cm and 1 cm length intervals of bream and roach, respectively. During all three periods, bream shifted from benthic cladocerans (Alona sp.) to zooplankton and chironomids within a transitional length of 15.0–20.0 cm. These foodshifts were coupled with a change in feeding behaviour from particulate to filter feeding. The biomass of chironomids was too low to sustain the consumption of larger bream (>20.0 cm) which initiated feeding in the pelagic zone even in periods when the mean length and biomass of the preferred zooplankton, Daphnia cucullata, were low. In contrast to bream, roach fed mainly on zooplankton. With increasing size, roach progressively shifted to larger zooplankton species due to the increasing mesh size of their branchial system. The importance of benthic animals in the diet of roach was minor due to low feeding efficiency on prey buried in the sediment. Detritus appeared in the diet of bream and roach in periods of low availability of animal food items. Feeding on detritus may provide an energetic advantage to bream and roach and increase the carrying capacity for these species in lakes, where detritus is highly abundant. Especially for the larger fish due to the decrease in their relative metabolic demands. However, the ability of bream to filter feed and with increasing size to retain food items smaller than those retained by roach may be the main mechanism for the dominance of bream over roach in highly eutrophic lakes.     

Condition factor and diet of Chrysichthys nigrodigitatus and Chrysichthys auratus (Siluriformes: Bagridae) from Aiba Reservoir, Iwo, Nigeria

Chrysichthys nigrodigitatus and C. auratus are important, highly valued and threatened freshwater species. To contribute with their ecological knowledge, the condition factor and diet of these two congeneric species were studied between April 2005 and April 2006. Food items of fish were evaluated by occurrence and numerical abundance methods, and the possible changes among sexes, seasons and sizes were considered. Results showed that generally C. nigrodigitatus were better conditioned than C. auratus. The males of C. nigrodigitatus and females of C. auratus were in better condition than their respective opposite sex throughout the year, and during the wet season compared to the dry. The food items of C. nigrodigitatus and C. auratus were similar and comprised twelve species belonging to five groups: Insecta (three species), Crustacea (five species), Arachnida (one species), Rotifera (one species) and Mollusca (two species). Other food items included fish scales, unidentified green eggs, plant parts, detritus and sand. Insecta and Crustacea dominated the food items in both species. For C. nigrodigitatus, insect consumption increased with fish size, while Crustacea items decreased (from 89.59% for 8.1cm - 12.0cm size class to 1.58% for 20.1cm - 26.0cm size class). However, while C. auratus smaller sized fish preferred Crustacea (98.72% for 8.1cm -12.0 cm size class), larger sized fish had both groups in relatively similar amounts. Schoener Overlap Index for both species and between seasons is 1.00. Diet breadth ranged from 0.00-1.47 for C. nigrodigitatus and 0.00-1.32 for C. auratus. Food Richness ranged from 0.00-1.44 for both species. Gut Repletion Index for C. nigrodigitatus and C. auratus are 76.39% and 76.27% respectively. Although, there is considerable similarity and overlap in the utilization of food resource for both coexisting species, condition factor and feeding behavior suggest strategies to reduce intra- and interspecific competition.     

Resource dependent growth and body condition dynamics in juvenile snakes: an experiment

We examined the manner in which animals adjust the proportion of energy allocated to growth and storage in response to food availability. We compared univariate growth and length-mass relationships between juvenile adders (Vipera berus) reared under two different feeding regimes. Animals in the low- and high-food experimental groups were fed suckling mice once and twice weekly, respectively. Snout-vent length, body mass, and body condition (residual scores from log-log regression of body mass on snout-vent length) were measured shortly after birth, and at 4, 9, and 14 weeks. We found that growth in length and mass, as well as changes in length-mass relationships, differed between treatments; snakes with access to more food not only increased faster in length but were also heavier at the completion of the experiment than were similar sized less frequently fed snakes. There was no association between body condition of individuals measured at birth and at the end of the experiment, whereas size at birth was a good predictor of final size. Our results provide evidence for resource-dependent allocation strategies in V. berus, and suggest that somatic growth is less sensitive to environmental fluctuations than body condition, presumably because body size is of greater importance for fitness.     

Biology of the marbled lungfish, Protopterus aethiopicus Heckel, in Lake Baringo, Kenya

In this paper we provide life history characteristics for an introduced marbled lungfish (Protopterus aethiopicus) population in Lake Baringo, Kenya, including their length–weight relationship, body condition, fecundity, sex ratio, reproduction and food. These data are compared with those of other populations. Samples were obtained from the commercial fishery between January and October 2001. The lungfish exhibited positive allometric growth, with the length–weight relationship described by the equation: logW = ?6.41 + 3.52 logTL. The mean relative condition factor was close to unity, did not vary much between months and was not significantly different between sexes. The overall sex ratio was skewed in favour of females. The size of fish at first maturity was 70–76 cm total length (TL) for females and 82–88 cm TL for males. Fish in maturity stages III–IV occurred in all monthly samples suggesting year round spawning. The marbled lungfish in Lake Baringo is largely piscivorous and its impact on other fishes certainly warrants further research.     

Gonadosomatic index‐based size at first sexual maturity and fecundity indices of the Indian River shad Gudusia chapra (Clupeidae) in the Ganges River (NW Bangladesh)

The present study aims to estimate the size at first sexual maturity and fecundity for female Gudusia chapra from the lower Ganges River, northwestern Bangladesh. A total of 250 female specimens, 3.60–13.70 cm in standard length (SL) and 1.00–43.60 g in body weight (BW), were collected during March–August 2006. The gonadosomatic index (GSI) for females was calculated by the equation, GSI (%) = (GW/BW) × 100. The size at first sexual maturity of females was estimated by the relationship between their gonadosomatic index and standard length. The specimen larger (≥8.00 cm in SL) than first size at sexual maturity was used for the estimation of fecundity. The size at first sexual maturity for female G. chapra was considered to be 8.00 cm SL in the Ganges River. The mean total fecundity was 20200 ± 6500 and ranged from 10800 to 36200. This study should be useful for fisheries biologists/managers to impose adequate regulations for sustainable‐fishery management in the Ganges River and elsewhere in Bangladesh.     

Feeding habits of larval Mirogrex terraesanctae (Steinitz, 1952) in Lake Kinneret (Israel) II. Experimental study

Interactions between the larvae of Mirogrex terraesanctae (Steinitz, 1952) in Lake Kinneret, Israel, and their zooplankton prey were studied experimentally. Prey species preference and size selectivities were measured. Larvae were hatched in the lab from eggs collected in the field, and fed different food items in various concentrations. The food items included lake zooplankton, algae, and commercial pellets. It was shown that small, first feeding larvae (7–8.5 mm SL) prefer small bodied zooplankters (< 180 µ). The effect of these food sources on larval growth was measured. It was found that larval Mirogrex grew at a higher rate when fed zooplankton prey sized from 63 µ–250 µ. Food items smaller than 63 µ, larger than 250 µ and Scenedesmus sp., produced less than optimal growth rates. The importance of Mirogrex feeding habits and their potential influence on the Kinneret ecosystem is considered.     

Shifts in the food of Nile tilapia, Oreochromis niloticus (L.) in Lake Victoria, Kenya

Studies of the food of introduced Nile tilapia, Oreochromis niloticus (L.) with respect to size, habitat and season were conducted between November 1998 and October 2000 in Kenyan waters of Lake Victoria. Stomach contents of 1980 specimens collected by demersal trawl and seining were analysed. Nile tilapia originally known to be herbivorous, feeding mostly on algae has diversified its diet to include insects, fish, algae and plant materials. The major diet of fish <5 cm total length was zooplankton whereas bigger fish included a wider range of food items in their diet. There was spatial variation in diet with insects and algae dominating in the gulf and open water habitats respectively. There was no seasonal variation in the food items ingested and diel feeding regime indicated that O. niloticus is a diurnal feeder. The shift in diet could be due to ecological and environmental changes in Lake Victoria, which have been associated with changes in composition and diversity of fish and invertebrate fauna, emergence and dominance of different flora including water hyacinth Eichhornia crassipes (Mart.) Solms‐Laub., and algae communities. The feeding habit of O. niloticus is discussed in the context of changes occurring in the lake.     

长江口盐沼植被生境内斑尾刺虾虎鱼食性特征

根据2015年5月至2016年4月在长江口东滩盐沼湿地水域采集的斑尾刺虾虎鱼样本数据,分析了该生境斑尾刺虾虎鱼的生物学和食性特征。结果表明:共采集到斑尾刺虾虎鱼186尾,其中6—8月采集的数量较高,而其他月份较低。约96%个体为幼体(平均体长109 mm),平均摄食等级为1.5。斑尾刺虾虎鱼主要摄食虾类(IRI(%)=69.05)、鱼类(IRI(%)=17.31)、蟹类(IRI(%)=11.51)和双壳类(IRI(%)=0.95)等11大类41小类饵料生物;虾类作为最重要的饵料类别,其生物量、数量和出现频次百分比均排列第一,以安氏白虾(Exopalaemon annandalei)、日本沼虾Macrobrachium nipponense)、长额刺糠虾(Acanthomysis longirostris)等虾类为主要饵料。鱼类饵料中,以大鳍弹涂鱼(Periophthalmus magnuspinnatus)、大弹涂鱼(Boleophthalmus valenciennes)等虾虎鱼科鱼类为主要饵料。各月平均饱满指数P(%)波动较大,6—11月呈逐渐增加趋势。随着体长的增加,饵料组成中鱼类的比例呈逐渐增高趋势,成体个体的饵料中鱼类的生物量比例达65%以上,虾类的比例则下降明显。6—8月斑尾刺虾虎鱼白天样本中鱼类饵料的重量百分比显著高于夜晚(P0.01),约是夜晚的8倍;但虾类则是夜晚显著高于白天(P0.01),约是白天的2倍,而蟹类饵料的昼夜差异不显著。从等级聚类(即组平均法)的分类方法可知,斑尾刺虾虎鱼各体长组食物组成在10%相似性水平上可分为3类,即41—60、61—180 mm和181—200 mm。从营养生态位宽度来看,41—60 mm体长组生态位宽度值为0.86,而61—120 mm体长组随着体长的增大而增大,但121—160 mm体长组生态位有所降低。盐沼生境丰富的饵料环境为斑尾刺虾虎鱼提供了良好的摄食场所,同时盐沼植被茂密的植株也可为幼体提供躲避捕食者的最佳庇护所,初步证明盐沼对于斑尾刺虾虎鱼具有重要的生境价值。     

Aspects of reproductive biology of Labeo horie Heckel (Pisces: Cyprinidae) in Lake Chamo, Ethiopia

Labeo horie Heckel is increasingly becoming commercially important in Lake Chamo but its reproductive biology in the lake is not well enough to guide its management. Sex ratio, breeding season, length at first maturity and fecundity of L. horie were studied from 1197 fish samples collected between August 1998 and October 1999 in Lake Chamo, Ethiopia. The sex ratio was significantly different (χ ² = 12.12, P < 0.001). The peak‐breeding period was during the rainy months of March to May, during which time more than 90% of both sexes had ripe gonads. The size at maturity ( L _m50 ) of males was 52 cm while the L _m50 of females was 62 cm. The smallest ripe male in the catch was 46.7 cm and weighed 890 g while the smallest ripe female caught was 49.5 cm and weighed 1145 g. The weight of ripe ovaries ranged from 54.3 g to 991.8 g and contained between 68,400 and 1,320,400 eggs. Relative fecundity ranged between 60 and 290 eggs per g of body weight. The relationships between fecundity and total length and between fecundity and total weight were curvilinear, while the relationship between fecundity and ovary weight was linear. L. horie conformed to the general pattern of reproduction in a tropical environment where peak‐breeding activity occurred during the rainy season. In order to protect the spawning population, fishing pressure should be minimized during breeding time at the shallower littoral regions.     

Feeding ecology of the orb-weaving spiderArgiope aurantia [Araneae: Araneidae] in a cotton agroecosystem

Twenty females of the orb-weaving spiderArgiope aurantia Lucas were introduced into a cotton field in east Texas in order to study the feeding ecology of this spider. In the 24 h after the release of these spiders in the cotton field, one had moved over a distance of 53 m. The released spiders spun webs with an average diameter of 33.5 cm with the hub an average of 39 cm above the ground. The diet ofA. aurantia was diverse which characterizes this species as a food generalist. Major food components were aphids (30%), Diptera (26.8%), grasshoppers (17.9%), and Hymenoptera (12.6%). The spiders' prey length ranged from 0.4 to 47 mm (mean =7.7±0.83 mm). Adult females ofA. aurantia have the potential to kill prey of up to ca. 200% of their own size. However, two-thirds of the prey items had a length of <3 mm, while only 25% of the prey items had a length of ≥20 mm.A. aurantia was found to be a predator of the cotton fleahopper (about 1% of the spiders' diet), which is a key pest of cotton.      

Diet and consumption rates of common dolphinfish,Coryphaena hippurus,in the eastern Arabian Sea

The aim of the study was to identify the diet composition, feeding preferences, size and sex related diet changes, and to calculate the consumption rates of common dolphinfish, Coryphaena hippurus, in the eastern Arabian Sea. Fish were caught using longline gear during the years 2006–2009. Stomachs of 238 specimens with fork lengths ranging from 324 to 1250 mm were analysed; 72 (30.25%) of the stomachs were empty. Epipelagic finfishes were the predominant prey followed by cephalopods and crustaceans. Occurrence of items such as sargassum, sea fans, corals, plastics and pieces of wood in the stomachs indicate an opportunistic and voracious feeding nature. Flyingfishes (family Exocoetidae), especially Exocoetus monocirrhus (%IRI 16.92), dominated the diet. Unidentified filefishes (family Monacanthidae), Sthenoteuthis oualaniensis, Euthynnus affinis, Cheilopogon furcatus and Cubiceps pauciradiatus were other important food items. The diet varied between sexes and different size classes. Juveniles and adults (size classes <75 cm, 75–95 and 95–115 cm) fed mainly on epipelagic finfishes, whereas the large adults (>115 cm) fed preferentially on cephalopods. Food consumption rate was higher in females (6.37% BW day^?1) compared to males (4.04% BW day^?1), and increased with their increase in size up to 75–95 cm length classes, thereafter decreasing. The daily meal and daily ration was 332.63 g day^?1 and 5.25% BW day^?1, respectively, and average annual food consumption was 121.41 kg.     

Diet,intestinal morphology,and nitrogen assimilation efficiency in the damselfish,Stegastes lividus,in Guam

Synopsis Analysis of stomach contents of Stegastes lividus revealed a shift from omnivory in juveniles to herbivory in adults. Red algae, primarily Polysiphonia spp., Gelidiopsis intricata and Ceramium spp., formed the bulk of the diet in all size classes. Foraminifera and small crustaceans were of particular importance in the diet of juveniles. Net nitrogen assimilation efficiency of field-fed S. lividus was approximately 61%, and did not vary with fish size. The net assimilation efficiencies of fish fed on Enteromorpha in the laboratory ranged from size-class means of 36–79% for nitrogen and from 29–72% for total organic material, and increased from juveniles to adults. Apparently, juveniles compensate for a lower efficiency in assimilating plant food by including a higher percentage of animal material in their natural diets. The ratios of intestine length to standard length (IL/SL) and to intestine diameter (IL/ID) increased rapidly in juveniles and leveled off in adults. The retention time for ingested food items may only be about one-half as long in juveniles as in adults. The combination of observed IL/ID ratios and estimated retention times proved most valuable in the interpretation of ontogenetic changes in feeding habits and assimilation efficiency.     

Effects of suspended clay on Daphnia body growth and fitness

1. Suspended sediments often reduce the abundance, fitness, and feeding rates of planktonic cladocerans. This paper examines the effect of suspended clay particles on the body growth and life-history parameters of Daphnia ambigua. Cohorts were exposed to zero or 50mgl^?1 suspended clay (particle size <2μm). Individuals exposed to clay had significantly lower body lengths at a given age than individuals in the control cohort. Parameters for the von Bertalanffy body growth equation were calculated for each individual; the asymptotic maximum body length (l_max) was reduced, but the growth rate constant (k) was unaffected, by the presence of suspended clay. Body length at reproductive maturity was lower in the presence of suspended clay; this may be an adaptive response and is similar to the response of cladocerans to limiting food concentrations. 2. Age-specific survivorship and fecundity were both reduced, and the ages of maturity and first reproduction were both increased, in the presence of suspended clay. The overall effect of these demographic changes was a 70% decline in the net reproductive rate (R_o), a measure of fitness. 3. Suspended clay affected the relationship between body length and fecundity. Animals of a given length produced fewer eggs in the presence of suspended clay. In addition, there was a significant interaction in the effects of body length and clay on brood size: the slope of the regression line of brood size as a function of body length was lower in the presence of clay. This interaction has also been observed in limiting food concentrations, and may be caused by reductions in body length at maturity in low food or high clay environments. 4. The similarity between the effects of limiting food concentrations and suspended clay on Daphnia body growth, survivorship, fecundity, and brood size makes sense, given previous observations showing that suspended clay reduces the feeding rate of D. ambigua by up to 70% due to mechanical interference with feeding behaviours.     

Reproductive potential of the Nile perch,Lates niloticus L. and the establishment of the species in Lakes Kyoga and Victoria (East Africa)

The size at first maturity, sex ratio and fecundity of L. niloticus in Lake Kyoga have been examined, and compared with the situation in other aquatic systems. The species has the ability to reproduce enormously. It produces up to 16 million eggs. In Lake Kyoga, fecundity (F) increases with length (L) in cm according to the equation: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaciOraiaac2% dacaGGGaGaaiinaiaac6cacaGG0aGaai4maiaacAdacaGGGaGaaiiE% aiaacccacaGGXaGaaiimamaaCaaaleqabaGaaiylaiaacAdaaaGcca% GGmbWaaWbaaSqabeaacaGGYaGaaiOlaiaacMdacaGGYaaaaaaa!44D8!\[\operatorname{F} = 4.436 x 10^{ - 6} L^{2.92} \]Information from different habitats shows that females grow to a larger size than males but the growth rate is the same in both sexes. Males mature earlier than females at 50–65 cm total length with females maturing between 60–95 cm. There are about twice as many males as females. The rapid establishment of L. niloticus in Lake Kyoga and the Nyanza Gulf of Lake Victoria following its introduction is attributed to the high reproductive potential of the species under favourable environmental conditions.     

Batch fecundity of Lutjanus carponotatus (Lutjanidae) and implications of no-take marine reserves on the Great Barrier Reef, Australia

This study investigated body size to fecundity relationships of a reef fish species targeted by line fishing, and examines the potential benefits of increased batch fecundity in no-take reserves compared to fished areas around the Palm, Whitsunday and Keppel Island Groups, Great Barrier Reef, Australia. Lutjanus carponotatus batch fecundity increased with fork length in a non-linear relationship that was best described by a power function. Batch fecundity differed by more than 100-fold among individuals, with a range from 7,074 to 748,957 eggs in fish ranging from 184 to 305 mm fork length. Furthermore, egg diameter increased with fish size. Based on underwater visual census, the potential batch fecundity per unit area in all three island groups ranged from 1.0 to 4.2 times greater in the no-take reserves than in the fished areas between 2001 and 2004. In 2002, a mean 2.3-fold difference in biomass between no-take reserves and fished areas converted to a mean 2.5-fold difference in batch fecundity per unit area. Greater batch fecundity, longer spawning seasons and potentially greater larval survival due to larger egg size from bigger individuals might significantly enhance the potential benefits of no-take marine reserves on the Great Barrier Reef.     

Feeding ecology and trophic level of Chimaera monstrosa Linnaeus, 1758 (Holocephali: Chimaeridae) in the Eastern Mediterranean

The feeding ecology of Chimaera monstrosa at a depth of 550?m was studied off S??ac?k Bay, Eastern Mediterranean, in 2008. Forty males and 57 females with a length between 7.80 and 45.5?cm were caught. 33 stomachs contained food items. The diet was composed of 11 prey items belonging to 6 groups: Bryozoa, Cnidaria, Crustacea, Mollusca, Tunicata, and Teleostei, of which Crustacea (IRI% [Index of Relative Importance]=80) and Mollusca (IR%=16) were the most abundant prey groups. The trophic level was estimated at 3.50, which is similar to the results from other studies in the western and northern part of the Mediterranean and the Atlantic Ocean but is higher than in the North Sea.