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... In other studies, S. scriba were caught using traditional fishing gears, such as floating nets and longlines, but these methods are more likely to injure or kill the fish [10,14,17,[72][73][74]. Working with live fish requires appropriate living conditions for the captured specimens, which means regular water changes, adequate oxygen levels and appropriate water temperature. ...
... We did not find any soft or hard prey in the stomachs examined that was not also found in the feces. Soft prey was also not found in the diet of S. scriba by the authors of other studies, regardless of the method used [10,14,17]. Thus, the non-destructive method does not lead to worse results. ...
... These parameters should be taken into account when interpreting and comparing results for the same geographic area. Indeed, if we compare two results from the Aegean Sea [14,100], we may assume that the differences in TROPH values are probably due to differences in fish body lengths (see Table 9), which may explain the difference in the values for the same region. Moreover, the trophic level for S. scriba calculated in our study (TROPH = 3.43 ± 0.53) is most similar to that of Labrus merula (TROPH = 3.47 ± 0.55), Symphodus ocellatus (TROPH = 3.4 ± 0.51), Mullus surmuletus (TROPH = 3.44 ± 0.53), Diplodus annularis (TROPH = 3.4 ± 0.46), Diplodus sargus (TROPH = 3.38 ± 0.51) and Diplodus vulgaris (3.5 ± 0.46), as calculated by Stergiou and Karpouzi [29]. ...
Serranus scriba is a common member of the coastal fish community in the Adriatic Sea, but knowledge about its feeding ecology is scarce. The aim of this paper is to present new evidence about its food preferences and feeding habits. An innovative non-destructive method of fecal pellet analysis was used for this study. This method does not require sacrificing specimens and the fish can be released back into the sea alive after the laboratory work. The results demonstrated that S. scriba mainly preys on decapods, followed by polychaetes, isopods, fish, mollusks and swarming shrimps. The calculated index of trophic diversity (ITD) value of 0.89 indicates that it is an opportunistic feeder that feeds on a wide range of different prey. According to the calculated trophic level of 3.43, which is higher than that of other members of the community, S. scriba is also an important piscivorous predator. With age, S. scriba undergoes an ontogenetic shift. The proportion of crustaceans, gastropods and polychaetes decreases with age and body size, while the proportion of fish increases.
في الفترة بين ديسمبر 2017 وفبراير 2018، تم تجميع 336 عينة سمكية من ثلاث أنواع تابعة لجنس البراكشة Serranus Spp. من موقع الصيد في جليانة ببنغازي لدراسة حالة تغذيتها وتكاثرها. أسماك النوع S. cabrilla والنوع S. hepatus لم تكن شديدة التغذية، خلافا للنوع S. scriba الذي كان جيد التغذية، كما كانت القشريات من مجدافيات الأرجل وصغار الجمبري اكبر مكونات غذاء الانواع السابقة بنسب 48.6، 33.7 و 36.1 % على التوالي، تليها مكونات غذائية متنوعة لكل نوع على حدى، كما ظهرت أعلى قيم معاملات الدليل الكبدي لدى S. cabrilla حتى 2.27 و 2.28 لدى S. hepatus و1.85 عند S.scriba، كما كانت أسماك S. cabrilla والنوع S. scriba ذات شقين متساويين جنسياً بوضوح، مع سيادة انثوية لدى S. hepatus. كذلك الدليل المنسلي G.S.I. كان عاليا مع زيادة الطول حتى (7.16) للاناث و (2.51) للذكور S. cabrilla. في حين كان أقل متوسط قيم لدى S. hepatus (0.98) يزداد حتى 3.96 لدي الإناث، أما S. scriba فقد زاد مع زيادة الطول حتى (4.44) في الاناث، وقد حصلت عينات S. cabrilla المتوسطة الطول (14.4 سم) على ربع مخزون العينات وكانت الاقل هي الاكبر (19.6 سم) حتى (3.6%)، أما أعلى نسبة ظهور للأسماك الاصغر من S. hepatus (10.4 سم) بنسبة 34.9% فكانت الاكبر هي الاقل حتى 2.3%، في حين كانت أسماك S. scriba الاكبر (18.4 سم) هي السائدة بتخطي حاجز الثلث من عينات الدراسة، في حين كانت أقل نسب ظهور لأصغر الاسماك حتى 2.7 %، وبشكل عام تفيد هذه الدراسة لتسهيل دراسة ديناميكية عشائر هذه الأنواع وتقدير مخزوناتها وحماية صغارها من الصيد الجائر.
The barred sand bass Paralabrax nebulifer is a commercially important fish off the west coast of Baja California Sur. To assess the diet of this species and variations as a function of sex and reproductive condition, 60 specimens were captured using traps during seven seasonal sampling trips from August 2016 to August 2018 in an adjacent area to Magdalena Bay, Baja California Sur, Mexico. The stomach contents of 50 specimens were obtained (23 males and 27 females). Sex was diagnosed by direct observation of the gonads. Based on the gonadosomatic index, hepatosomatic index, and histological analyses, the reproductive season of the barred sand bass was corroborated for August 2016, April, August, and September 2017, and August 2018, and the non-reproductive season was corroborated for November 2016 and March 2018. The Index of Relative Importance (IRI) was used to classify the main diet components, which comprised three fish species, seven crustacean species, and one mollusk species. According to the IRI, the South American pilchard Sardinops sagax and the red pelagic crab Pleuroncodes planipes were the prey that contributed the most (55%) to the barred sand bass diet. The ANOSIM showed that there were significant differences in the amount and type of prey consumed by sex; the SIMPER analysis revealed that the species contributing the most to differences between the sexes were S. sagax (16.58%), Euphylax dovii (15.95%), Stenocionops ovata (12%), and P. planipes (11.82%) for females. There were significant differences in the amount and type of prey consumed between types of reproductive season; the species contributing the most to differences between seasons were Anchoa spp. (27.76%), and P. planipes for non-reproductive season (22.67%), and S. sagax (11.08%) for reproductive season. The feeding strategy of the barred sand bass was that of a specialist carnivorous predator that fed mainly on the fish Sardinops sagax during the reproductive season, which supply the dietary nutritional requirements of the lipids HUFA (arachidonic acid, 20:4n-6; eicosapentaenoic acid, 20:5n-3; docosahexaenoic acid, 22:6n-3), nutrients required to achieve reproductive success.
From December 2017 to Febraury 2018, 336 specimens of three species of Serranus spp. were collected from Jilianah harbor, Benghazi, to study the length-weight relationship, condition factors, food and feeding, and reproduction situation as well. Specimens of S. cabrilla and C. hepatus had no intensive feeding, unlike S. scriba, which was well-fed. Crustaceans like copepods and young shrimps were dominated at the menu of our species at 48.6, 33.7 and 36.1%, respectively, followed by a highly-various food ingredients for each species. The highest values of the S. cabrilla H.S.I. were 2.27, 2.28 at S. hepatus and 1.85 for S. scriba specimens. Individuals of S. cabrilla and S. scriba were clearly equal sex ratio, with female dominance in S. hepatus study stock. G.S.I. was also high with size increasing to (7.16) for females and (2.51) for males of S. cabrilla. Meanwhile the nadir values of S. hepatus (0.98) peaked to 3.96 dramatically in females. It was increased with S. scriba with length to 4.44 in females. The med-sized specimens of S. cabrilla (14.4 cm) obtained a quarter of study stock, and the highest incidence of S. hepatus (10.4 cm) was 34.9%, and was the lowest in the largest group (2.3%), while the largest S. scriba (18.4 cm) was predominant by more than a third of the study samples, and the least appearance of the smallest ones to 2.7%, This study is beneficial to facilitate studies of the population dynamics of these species and other economically-important fish in the Libyan coast, to work on the fish stocks assessment, and to protect the juveniles from overfishing.
