Some Quality Parameters of Meat from Popular Marine
Fish Species Brought from Port Sudan City, Red Sea State,
Sudan
Alya Mohammed Suliman Abdelgadir
B.Sc. in Chemistry/Biology, Faculty of Education, University of Holy Quran (2010) Postgraduate Diploma in Biosciences and Biotechnology, University of Gezira (2013)
A Dissertation
Submitted to the University of Gezira in Partial Fulfillment of the
Requirements for the Award of the Degree of Master of Science
in
Biosciences and Biotechnology (Biotechnology)
Center of Biosciences and Biotechnology
Faculty of Engineering and Technology
May 2016
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Some Quality Parameters of Meat from Popular Marine
Fish Species Brought from Port Sudan City, Red Sea State,
Sudan
Alya Mohammed Suliman Abdelgadir
Supervision Committee: Name Position Signature
Dr. Yasir Mohamed Abdelrahim Main Supervisor ……………….
Dr. Mutaman Ali A. Kehail Co-supervisor …….……….
Date: May 2016
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Some Quality Parameters of Meat from Popular Marine
Fish Species Brought from Port Sudan City, Red Sea State,
Sudan
Alya Mohammed Suliman Abdelgadir
Examination Committee: Name Position Signature
Dr. Yasir Mohamed Abdelrahim Chairperson …………….
Prof. Elnaeim Abdalla Ali External Examiner …….……….
Dr. Zakaria Ahmed Salih Internal Examiner ……………..
Date of Examination: 16/ May/ 2016
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DEDICATION
To my family
To my parents, Mohamed Suliman, Aayda Mohamed and my husband Khlid Taha ,and my sisters for their support, patience and
understanding…. to all those who helped me …. I Dedicate this
work
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ACKNOWLEDGEMENT
First of all, my thanks and praise to almighty Allah, the most beneficent merciful for giving me health to accomplish this work.
I wish to express my thanks to my supervisor Dr. Yasir Mohamed
Abdelrahim. Special thanks to Dr. Mutaman Ali Kehail for his guidance, and advice through-out my work.
Finally I would like to thank the lab teams of both the Laboratory of
Food Analysis, Faculty of Engineering and Technology, University of
Gezira and Laboratory teams of Chemistry, Customhouse Laboratory,
Port Sudan for their appreciated support.
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Some Quality Parameters of Meat from Popular Marine Fish Species Brought from Port Sudan City, Red Sea State, Sudan
Abstract Fish are an important resource for humans worldwide. Catching fish for the purpose of food (specially for omega-3 fatty acids, which reduce risks of heart disease, cancer and depression) or sport is known as fishing. This study aim to compare the meat quality (proximate and minerals contents) of eight popular fish species (Hump head wrasse, Gilt-head bream, Electric ray, Grouper, Lethrinus, Mullet, Sander and the milkfish) found in fish market of Port Sudan City, Red Sea State, Sudan, during October 2014. The fish samples were cleaned, cut from internal abdominal parts, then prepared to carry out the proximate and mineral contents tests. These tests were run at the Laboratory of Food Analysis, Faculty of Engineering and Technology, University of Gezira, whereas, the mineral contents (in mg/100g) profile was done in the Laboratory of Chemistry, Customhouse Laboratory, Port Sudan. The results of this study showed that, concerning the proximate contents: the tested fish meat contained carbohydrates (animal starch) between 0.68% in Hump head and 3.6% in Electric ray, whereas, fat content ranged between 10.33% in Electric ray fish, and 16% in Hump head, moisture content ranged between 66.06% in Hump head, and 70.64% in Sander, ash content ranged between 1.45% in Grouper and 2.79% in Mullet, protein content ranged between 9.97% in Mullet and 15.89% in Gilt-head bream. Concerning mineral contents: Potassium (K) content ranged between 14.7 in Lethrinus nebulosus and 20.2 in Grouper. Calcium (Ca) content ranged between 1.1 in L. nebulosus and 12.3 in Hump head. Barium (Ba) content ranged between 0.0 and 0.1, whereas, Fe was not detected in all fish species. ANOVA proved no significant differences between fish meat samples in their proximate contents, while it proved a significant differences in their mineral contents. The study recommend giving some aware to the fish meat because of its potential health benefits and further studies should be run on fish and fish products such as omega-3 fatty acids as medical supplements.
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بعض خصائص الجودة للحوم أنواع األسماك البحرية الشائعة المستجلبة من مدينة بورتسودان، والية البحر
االحمر، السودان
ملخص الدراسة
األسماك من المصادر المهمة لإلنسان في كل العالم. إمساك األسماك لغرض الطعام )خصوصاً األحماض
الدهنية أوميقا-3, والتي تخفض مخاطر أمراض القلب, السرطان واإلكتئاب( أو لغرض الرياضة تعرف بالصيد.
هدفت هذه الدراسة لمقارنة جودة اللحوم )المكونات التقريبية والمعادن( لثمانية أنواع من األسماك الشائعة
)نابليون، قشري، الرعاد، الدنيس، السلماني، البياض البحري، عربي، الشعري ( الموجودة في سوق أسماك مدينة
بورتسودان, والية البحر األحمر, السودان خالل إكتوبر 2016.تم تنظيف عينات األسماك, وأزيلت األجزاء
البطنية الداخلية, ثم جهزت لتجري عليها إختبارات المحتويات التقريبية والمعدنية. أجريت هذه اإلختبارات في
معمل تحليل األغذية, كلية الهندسة والتكنولوجيا, جامعة الجزيرة, بينما تم إجراء إختبارات المحتويات المعدنية
)بالملجرام/100 جم( في معمل الكيمياء, المعمل الجمركي, بورتسودان. أوضحت نتائج هذه الدراسة اآلتي: فيما
يتعلق بالمحتويات التقريبية, أن لحوم األسماك المختبرة تحتوي علي كربوهيدرات )النشأ الحيواني( تتراوح بين
3.6% في سمك الرعاد و%0.68 في سمك نابليون, بينما تراوح المحتوي الدهني بين %10.33 في أسماك
الرعاد و %16 في سمك نابليون, وتراوح المحتوى المائى بين %66.06 في سمك نابليون و %70.64 في
سمك البياض البحري, وتراوح الرماد بين %1.45 في سمك قشري و %2.79 في سمك عربي, وتراوح محتوى
البروتين بين %9.97 في سمك عربي و %15.89 في سمك الدنيس. وفيما يخص المحتوي المعدني: تراوح
محتوي البوتاسيوم بين 14.7 في سمك الشعري و 20.2 في سمك قشري. تراوح الكالسيوم بين 1.1 في سمك
الشعري و 12.3 في سمك نابليون. تراوح الباريوم بين 0 و 0.1, بينما لم يتم تحديد الحديد في كل أنواع
األسماك. أثبت إختبار تحليل التباين عدم وجود فرق معنوي بين عينات لحوم األسماك في محتوياتها التقريبية,
بينما أثبت وجود إختالف معنوي بين محتوياتها المعدنية. أوصت الدراسة بإعطاء بعض اإلهتمام للحوم األسماك
بسبب فوائدها الصحية المحتملة واج ارء د ارسات الحقة علي األسماك ومنتجات األسماك مثل األحماض الدهنية
أوميقا-3 كمعوضات عالجية.
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TABLES OF CONTENTS
Subject Page Dedication iv Acknowledgements v Abstract vi Arabic Abstract vii Table of Contents ix List of Tables x List of Plates xi CHAPTER ONE: INTRODUCTION 1 CHAPTER TWO: LITERATURE REVIEW 3 2.1 Fish 3 2.1.1 Muscular system 3 2.1.2. Health benefits and possible risks of eating fishes 4 2.1.3. Chemical analysis of fish 5 2.1.4. Red Sea species hazardous to humans 6 2.1.4.1. Biting and wounding fish 6 2.1.4.2. Poisonous fish 6 2.1.4.3. Stinging and venomous fish 10 2.1.4.4. Ciguatera poison 10 2.1.5. The fish species mentioned in this study 10 10 (نابليون) Humphead wrasse 2.1.5.1 2.1.5.1.1. Scientific classification 11 2.1.5.1.2. Habitat 11 2.1.5.1.3. Description 11 14 (الدنيس) Gilt-head bream .2.1.5.2 2.1.5.2.1. Scientific classification 14 2.1.5.2.2. Biology 14 2.1.5.2.3 Fisheries and aquaculture 16 16 (الرعاد) Electric ray .2.1.5.3 2.1.5.3.1. Scientific classification 16 2.1.5.3.2. Description 18
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18 (اوقشري) Grouper .2.1.5.4 2.1.5.4.1. Scientific classification 20 2.1.5.4.2. Description 20 21 (الشعري) Lethrinus nebulosus .2.1.5.5 2.1.5.5.1. Scientific classification 21 2.1.5.5.2. Description 21 23 (عربي) Mullet .2.1.5.6 2.1.5.6.1. Scientific classification 23 25 (البياض البحري) Sander Sander lucioperca .2.1.5.7 2.1.5.7.1. Scientific classification 25 2.1.5.7.2. Description 25 27 (السلماني) (The milkfish (Chanos chanos .2.1.5.8 2.1.5.8.1. Scientific classification 27 2.1.5.8.2. Description and biology 27 CHAPTER THREE: MATERIALS AND METHODS 29 3.1 Sampling of Materials: 29 3.2 Methods 29 3.2.1 Moisture content 29 3.2.2 Ash content 29 3.2.3 Oil content 30 3.2.4. Protein content 30 3.2.5 Carbohydrate content 31 3.2.6 Mineral contents 31 3.3 Statistical analysis 31 CHAPTER FOUR: RESULTS AND DISCUSSION 32 4.1 Nutritional values of the selected fishes 32 4.2 The detected elements in the tested fishes 34 CHAPTER FIVE: CONCLUSIONS AND RECOMMENDATIONS 36 5.1 Conclusions 36 5.2 Recommendations 36 REFERENCES 37
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LIST OF TABLES Tab. No. Title Page
2.1 Protein, fat and moisture content in some popular local 7
fishes
4.1 Proximate values of the meats of the selected fishes 33
4.2 The element contents (mg/100 g) in the meats of the 35
selected fishes
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LIST OF PLATES Plate No. Title Page 1 Some of the Red Sea fishes 9 2 Male humphead wrasse fish 12 3 Sparus aurata fish 15 4 Lesser electric ray (Narcine bancroftii) 17 5 Malabar grouper, Epinephelus malabaricus 19 6 Lethrinus nebulosus fish 22 7 Mugil cephalus fish 24 8 S. lucioperca fish 26 9 The milkfish (Chanos chanos) 28
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CHAPTER ONE INTRODUCTION
Fish are an important resource for humans worldwide, especially as food. Commercial and subsistence fishers hunt fish in wild fisheries or farm them in ponds or in cages in the ocean. They are also caught by recreational fishers, kept as pets, raised by fishkeepers, and exhibited in public aquaria. Fish have had a role in culture through the ages, serving as deities, religious symbols, and as the subjects of art, books and movies. Because the term "fish" is defined negatively, and excludes the tetrapods (i.e., the amphibians, reptiles, birds, and mammals) which descend from within the same ancestry, it is paraphyletic, and is not considered a proper grouping in systematic biology. The traditional term pisces (also ichthyes) is considered a typological, but not a phylogenetic classification (Helfman et al., 1997). The omega-3 fatty acids, eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), have many health benefits such as reducing risks of heart disease, cancer and depression. EPA and DHA are found in oily fish and are also available in dietary supplements. The 2010 Dietary Guidelines for Americans recommend 1,750 mg EPA and DHA/wk, or 250 mg/day, which can be reached by consuming 8 ounces of seafood/week. For many people, achieving this recommended amount of EPA and DHA through diet alone may be difficult unless supplements are also used. Though the health benefits of fish oil are relatively clear, the content, purity and price of EPA and DHA needed for the recommended dosage is highly confusing (Belury, 2011). Catching fish for the purpose of food or sport is known as fishing, while the organized effort by humans to catch fish is called a fishery. Fisheries are a huge global business and provide income for millions of people. The annual yield from all fisheries worldwide is about 154 million tons, with popular species including herring, cod, anchovy, tuna, flounder, and salmon. However, the term fishery is broadly applied, and includes more organisms than just fish, such as mollusks and crustaceans, which are often called "fish" when used as food (Moyle, 1993; Shubin, 2009). Although most species in the Red Sea pose no threat to humans, there are a few notable exceptions. Biting and wounding fish e.g. tiger shark, Titan triggerfish,
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Yellow margin triggerfish, Giant moray and Grey reef shark has been involved in non-fatal attacks on divers (Daley, 1994; Lieske and Myers, 2004). Stinging and venomous fish, e.g. Stonefish, Lionfish, Scorpion fish, Stingrays and the Blue spotted stingray (Lieske and Myers, 2004). Ciguatera poisoning is a danger posed by fish at the top of the food chain, in particular the Twinspot snapper and Giant moray. These fish accumulate a toxin produced by a dinoflagellate which is eaten by their prey species (Froese and Pauly, 2007). Pufferfish, including this masked puffer accumulate a neurotoxin called tetrodotoxin in their skin and internal organs. Boxfish also accumulate tetrodotoxin and are poisonous to eat. Soap-fishes produce the bitter toxin grammistin from their skin to deter predators. This may cause illness in humans (Lieske and Myers, 2004). The Portuguese Man o' War is a floating hydrozoan with retractile tentacles, and which produce extremely painful stings. Cone shells house molluscs which use a venomous harpoon to kill their prey. Fire coral, millepora spp has stinging nematocysts on its surface. Crown-of-thorns starfishes are covered in spines which have a venomous sheath. The venom may cause highly painful wounds and even paralysis (Froese and Pauly, 2007). This study targeting some of the most popular species of edible fishes that found in the fish market of Port Sudan City, Red Sea State, in order to run a comparative nutritional studies on these fish meats.
Objective: This study aim to compare the meat quality (proximate and minerals contents) of some popular fishes species found in fish market of Port Sudan City, Red Sea State, Sudan, during October 2014.
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CHAPTER TWO LITERATURE REVIEW
2.1 Fish A fish is any member of a paraphyletic group of organisms that consist of all gill-bearing aquatic craniates animal that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups. Most fish are ectothermic (cold-blooded), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature. Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., gulpers and anglerfish). With 33,100 described species, fish exhibit greater species diversity than any other group of vertebrates (Eschmeyer and Fong, 2013). The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods (Moyle and Cech, 2003). 2.1.1 Muscular system Most fish move by alternately contracting paired sets of muscles on either side of the backbone. These contractions form S-shaped curves that move down the body. As each curve reaches the back fin, backward force is applied to the water, and in conjunction with the fins, moves the fish forward. The fish's fins function like an airplane's flaps. Fins also increase the tail's surface area, increasing speed. The streamlined body of the fish decreases the amount of friction from the water. Since body tissue is denser than water, fish must compensate for the difference or they will sink. Many bony fish have an internal organ called a swim bladder that adjusts their buoyancy through manipulation of gases (Nelson, 2006).
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2.1.2. Health benefits and possible risks of eating fishes Omega-3 fatty acids are found in fish, especially, oily fish such as salmon, sardines, and herring. These omega-3 fatty acids can help lower your blood pressure, lower your heart rate, and improve other cardiovascular risk factors. Eating fish reduces the risk of death from heart disease, the leading cause of death in both men and women. Fish intake has also been linked to a lower risk of stroke, depression, and mental decline with age. For pregnant women, mothers who are breastfeeding, and women of childbearing age, fish intake is important because it supplies DHA, a specific omega-3 fatty acid that is beneficial for the brain development of infants (Janet et al., 2006). Some fish contain mercury. For men and women not of childbearing age, it is not clear that mercury exposure from typical levels of fish intake has any adverse health effects. In contrast, fish intake has significant benefits for reducing the risk of death from heart disease, the number one cause of death. So, mercury exposure from fish intake should not be a major concern for men or for women not of childbearing age. The benefits of fish intake can be maximized by consuming a variety of different seafood. Mercury may have subtle effects on the developing nervous systems of infants. Therefore, pregnant women, women who may become pregnant, those who are breastfeeding, and very young children should avoid 4 types of fish that are higher in mercury content: shark, swordfish, king mackerel, and golden bass. Other fish should still be consumed to ensure that infants receive the benefits of DHA for brain development. Light tuna has relatively low levels of mercury, and other fish, such as wild and farmed salmon and shrimp, contain very low levels of mercury. Chemicals called dioxins and polychlorinated biphenyls (PCBs) can accumulate in foods, including fish. The levels of these chemicals in fish, including farmed fish, are very low and similar to levels in meats and dairy products. Compared with the health benefits of fish intake, the health risks of these chemical levels are very low and should not influence individual decisions about fish intake. Compared with store- bought fish, locally caught freshwater fish may have higher chemical levels, so local advisories should be consulted (Janet et al., 2006). Throughout history, humans have utilized fish as a food source. Historically and today, most fish protein has come by means of catching wild fish. However, aquaculture, or fish farming, which has been practiced since about 3,500 BCE. in
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China, is becoming increasingly important in many nations. Overall, about one-sixth of the world's protein is estimated to be provided by fish. That proportion is considerably elevated in some developing nations and regions heavily dependent on the sea. In a similar manner, fish have been tied to trade (Helfman et al., 2009). With around 1000 species of fish (Plate, 1) and 150 species of coral, the Red Sea is rich in marine life (Ewald and Robert, 2004). 2.1.3. Chemical analysis of fish Ala Eldeen (1994) stated that, fish body contains different proportions of water, protein, fat, glycogen and salts. The percentage of water ranges between 66% and 84%, protein between 15% and 24% and fat between 1% and 22% .The glycogen have a low percentages. Salts percentage found to be ranging between 0.8% and 2%, in addition total soluble vitamins in fats, in particular, A, D, E and K. Abdul Hamid, (1994) explained that, the chemical composition depend on the gender, age, physiological status and the time and location of fishing. He also stated that, fish meat is classified to three grades according to fat content. The best is lean fish where fat content is about 2%, the second grade is medium fatty fish and lowest grade is the fatty fish where the fat content is above 5%. Elder fish meat is characterized by high fat percent and low percentage of water and vice versa in case of young fish. On the other hand, when the fishes are in poor nutritional status during migration and reproduction, the fat content in meat decreases where the water content increases. After wards, during the period of good nutrition that follows the breeding, the meat becomes more obese with minimum water content. Fish meat is found to be affected by the nutritional status of water as fish meat in rich Greasy water with higher nutrient content found to be of higher fat content than those in the static water of scarce food. These differences may be due to different environmental conditions regarding food, currents, temperature and salts according to (Abdul Hamid, 1994 ) The gender may also plays an important role in the chemical composition, depending on ages, sizes and physiological status, likewise he stated that, the protein content and energy content increases with the water content decrees. Protein content, fat content and energy in fish increases with the decrees of water content. It was found that, it is possible to calculate the constituents of fish body using its weight, length and specific conversion factor as all fish contents and tissues increase
16 proportionally with the fish weight according to Ala Eldeen (1994). However, he also stated that, fish fat may decreases by 1% as in hadok fish or increase by 44% as of Fish Sardines (on dry weight basis) in addition to an inverse relationship between fat content and water in fish muscles. In general the percentage of water in the fresh fish is 80% on the average for the white fish and 70% for the red fatty fish. The following tables summarize the findings of a group of scientists and organizations regarding the chemical analysis of fresh fish. 2.1.4. Red Sea species hazardous to humans Although most species in the Red Sea pose no threat to humans, there are a few notable exception which include: 2.1.4.1. Biting and wounding fish The tiger shark is considered to be one of the most dangerous sharks to humans. Although it is found in the Red Sea it is not usually seen near reefs during the daytime. The Grey reef shark is territorial and may be aggressive, and has been involved in non-fatal attacks on divers (Daley, 1994). The Titan triggerfish, will guard its nest aggressively if eggs are present. Attacks can be severe and leave wounds requiring stitches. The Yellow margin triggerfish, is another large triggerfish and should not be disturbed if tending to eggs. Moray eels such as the Giant moray are only occasionally aggressive; most bites result from divers putting a hand into the hole in which the eel lives. Surgeon fishes have sheathed or fixed blades at the base of the tail which can inflict deep wounds (Lieske and Myers, 2004). 2.1.4.2. Poisonous fish Puffer-fish, including this masked puffer accumulate a neurotoxin called tetrodotoxin in their skin and internal organs. This toxin is extremely potent and has been responsible for many fatalities. Boxfish also accumulate tetrodotoxin and are poisonous to eat. This is the Yellow boxfish, Ostracion cubicus which is widespread in the Red Sea. Soap-fishes produce the bitter toxin grammistin from their skin to deter predators. This may cause illness in humans (Lieske and Myers, 2004).
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Table ( 2.1) Protein, fat and moisture content in some popular local fishes
Species Protein Fat Moisture Bagrus 21.14 – 23.1% 4.9 – 0.04 % 80.77- 81.86 % Clarias 17.58 1.15 % 80 % Domak 19.64 1.77% ND Hyperopisus bebe 18.55 – 15.99 % 1.4 ± 0.81 % 83.29 -78.50 % Labeo coubie 17.89% 1.95 % ND Lates niloticus 22.02 – 15.81 % 2.58±0.36 % 75.79 – 81.33 % Mormyrus niloticas 16.75 2 % 75.4 % Sinodontis 19.65 -14.99 % 1.24 ± 0.81 % 83.51 - 75.19 % Telabia niloticus 19.01- 15.51 % 2.58±0.36 % 83.29 – 78.60 %
ND: not determined Source: (Osman, 2012; Zohar, 1977; Gok , 2005; Samia, 2004)
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Blue Spotted Stingray, Taeniura lymma Blackspotted Sweetlips Plectorhinchus gaterinus
Giant Moray Eel, Gymnothorax Geometric / Grey / Snowflake Moray Eel, javanicus Sidera grisea
Lionfish (Turkeyfish), Pterois miles Red Sea Clownfish, Amphiprion bicinctus
Coral Grouper (Coral Rock-Cod), Lyretail Anthias, Pseudanthias Cephalopholis miniata squamipinnis
Plate (1-a) Some of the Red Sea fishes
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Picasso Trigger Fish, Rhinecanthus Masked Puffer, Arothron diadematus assasi
Squirrelfish, Sargocentron spiniferum Freckled Hawkfish, Paracirrhites forsteri
Crown Butterfly Fish, Chaetodon Masked Butterfly Fish, Chaetodon paucifasciatus semilarvatus
Emperor Angelfish Bluefin Trevally
Plate (1-b) Some of the Red Sea fishes Source: Ewald and Robert (2004)
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2.1.4.3. Stinging and venomous fish The spines on the back of the Stonefish are venomous and can penetrate a rubber-soled shoe. The fish is extremely well camouflaged and care should be taken to avoid stepping on it. The venom can be fatal. Lionfish such as Pterois miles have stinging spines which rarely inflict a fatal wound but which may be extremely painful. Scorpion fish have venomous spines similar to those of the stonefish, and although the venom is less deadly it may still prove fatal. The dorsal, pelvic and anal fins of the Rabbit fishes have venomous spines, capable of inflicting painful wounds. Stingrays have sharp detachable spines at the base of the tail, capable of causing severe wounds. Pictured is the Blue spotted stingray (Lieske and Myers, 2004). 2.1.4.4. Ciguatera poison Ciguatera poisoning is a danger posed by fish at the top of the food chain, in particular the Twin-spot snapper and Giant moray. These fish accumulate a toxin produced by a dinoflagellate which is eaten by their prey species. Ciguatera poisoning can be fatal (Froese and Pauly, 2007). The Portuguese Man o' War is a floating hydrozoan with retractile tentacles which may be several meters long, and which produce extremely painful stings. Cone shells house molluscs which use a venomous harpoon to kill their prey. The venom causes paralysis which may lead to death. These shells should not be picked up if there is any chance the organism is still alive. Fire coral, millepora spp is a hydrozoan which has stinging nematocysts on its surface. The chief danger of fire coral is to snorkellers or divers brushing against it. Crown-of-thorns starfishes are covered in spines which have a venomous sheath. The venom may cause highly painful wounds and even paralysis (Froese and Pauly, 2007). 2.1.5. The fish species mentioned in this study (نابليون) Humphead wrasse 2.1.5.1 The humphead wrasse (Cheilinus undulatus) is a species of wrasse mainly found on coral reefs in the Indo-Pacific region. It is also known as the Māori wrasse, Napoleon wrasse, Napoleon fish, Napoleonfish, mameng (Filipino), and merer in the Pohnpeian language of the Caroline Islands (Russell, 2004).
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2.1.5.1.1. Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Perciformes Family: Labridae Genus: Cheilinus Species: undulates, (Russell, 2004)
2.1.5.1.2. Habitat The humphead wrasses can be located within the east coast of Africa and Red Sea as well as in the Indian Ocean to the Pacific Ocean. There are different ranges in which juvenile and adult humphead wrasses are found. Juveniles are usually found in shallow sandy ranges that are bordering coral reef waters, while adults are mostly found in offshore and deeper areas of the coral reefs, typically in outer-reef slopes and channels but can also be found in lagoons. Humphead wrasses are found in small groups or larger combinations within their habitat (Sluka,2005; Tupper, 2007). 2.1.5.1.3. Description The humphead wrasse (Plate, 2) is the largest living member of the Labridae family. Males are typically larger than females and are capable of reaching lengths of up to 2 meters from tip to tail and weighing up to 180 kg, but the average length is generally a little less than 1 meter. Females rarely grow larger than one meter in length. This species of fish can be easily identified by its large size, thick lips, two black lines behind its eyes, and the hump that appears on the forehead of larger adults. The color of the humphead wrasse can vary between a dull blue-green to more vibrant shades of green and purplish-blue. This particular reef fish prefers to live singly but adults are occasionally observed moving in small groups (Chateau, 2007; Weng et al., 2015).
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Plate (2) Male humphead wrasse Source: Russell (2004)
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The humphead wrasse is long-lived, but has a very slow breeding rate. Individuals become sexually mature at four to six years, and females are known to live for around 50 years, whereas males live a slightly shorter 45 years. Humphead wrasses are protogynous hermaphrodites, with some members of the population becoming male at about 9 years old. The factors that control the timing of sex change are not yet known. Adults move to the down-current end of the reef and form local spawning aggregations (they concentrate to spawn) at certain times of the year (Sadovy, 2003). It is speculated that Humphead Wrasse do not travel very far for their spawning aggregations (Chateau and Lantiez, 2007). The humphead Wrasse produces pelagic eggs and larvae that ultimately settle on or near coral reef habitats. Eggs are 0.65 mm in diameter and spherical, with no pigment (Sadovy, 2003). Being very opportunistic predators, the Cheilinus undulatus prey primarily on invertebrates such as mollusks (particularly gastropods and pelecypods), echinoids, crustaceans, annelids) and vertebrates, in the form of fish. Half of echinoids and most pelecypods hide under the sand, leaving scientists to believe one of two options: the humphead wrasses rely on fish excavators like stingrays, or they themselves excavate by ejecting water and nosing around to look for prey. Often, these wrasse, alone with many other Red Sea wrasses, crack sea urchins (echinoids) by carrying them to a rock in their mouths and striking them against a rock by moving their heads in sideways, brisk movements (Randall, 1978). Ocean acidification is becoming a very big threat to coral reefs because it is reducing the calcification rate of coral species. These coral species will be pushed beyond what they can handle in terms of growth and survival for decades to come.
Due to an increased concentration of atmospheric CO2, the pH of Earth’s oceans are causing this acidification, and therefore decline in reef building activity. Adults are commonly found on steep coral reef slopes, channel slopes, and lagoon reefs in water 3 to 330 ft (1–100 m) deep. From this loss of calcifying coral, this endangered species may someday also lose its home (Anthony, 2008). This species actively selects branching hard and soft corals and sea-grasses at settlement. Juveniles tend to prefer a more cryptic existence in areas of dense branching corals, bushy macro algae, or sea-grasses, while larger individuals and adults prefer to occupy limited home ranges in more open habitat on the edges of reefs, channels, and reef passes. The species is most often observed in solitary male- female pairs, or groups of two to seven individuals (Tupper, 2007).
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(الدنيس) Gilt-head bream .2.1.5.2 The gilt-head bream (Sparus aurata; Plate, 3) is a fish of the bream family Sparidae found in the Mediterranean Sea and the eastern coastal regions of the North Atlantic Ocean. It commonly reaches about 35 cm (1.15 ft) in length, but may reach 70 cm (2.3 ft) and weigh up to about 17 kilograms (37 lb). The gilt-head bream is generally considered the best-tasting of the breams. It is the single species of the genus Sparus – the Latin name for this fish – which has given the whole family of Sparidae its name. Its specific name, aurata, derives from the gold bar marking between its eyes (Froese and Pauly, 2010).
2.1.5.2.1. Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii
Order: Perciformes
Family: Sparidae Genus: Sparus Species: aurata, (Froese and Pauly, 2010)
2.1.5.2.2. Biology The gilt-head bream at Spiaggia de La Pelosa on the north west coast of Sardinia, Italy. It is typically found at depths of 0–30 meters (0–98 ft), but may occur up to 150 m (490 ft), seen singly or in small groups near sea-grass or over sandy bottoms, but sometimes in estuaries during the spring. It mainly feeds on shellfish, but also some plant material (Froese and Pauly, 2010).
25
Plate (3): Sparus aurata fish Source: Froese and Pauly, (2010)
26
2.1.5.2.3 Fisheries and aquaculture Gilthead bream is an esteemed food fish, but catches of wild fish have been relatively modest, between 6,100 and 9,600 tonnes in 2000–2009, primarily from the Mediterranean (FAO, 2011). In addition, gilthead bream have traditionally been cultured extensively in coastal lagoons and saltwater ponds. However, intensive rearing systems were developed during the 1980s, and gilthead bream has become an important aquaculture species, primarily in the Mediterranean area. Reported production was negligible until the late 1980s, but reached 140,000 tonnes in 2010, thus dwarfing the capture fisheries production. The fish is widely used in Mediterranean cooking, under a variety of names: in Bulgaria it is called tsipúra, in Egypt it is called denees, in Germany the fish is called Goldbrasse or Dorade, in Turkey the fish is referred to as çipura or çupra, in Tunisia it is called wourata, in Morocco it is called chargho, also daurade (Alan, 1972).
(الرعاد) Electric ray .2.1.5.3 The electric rays are a group of rays (Plate, 4), flattened cartilaginous fish with enlarged pectoral fins, comprising the order Torpediniformes. They are known for being capable of producing an electric discharge, ranging from 8 to 220 volts, depending on species, used to stun prey and for defense. There are 69 species in four families. Perhaps the best known members are those of the genus Torpedo, also called crampfish and numbfish, after which the device called a torpedo is named. The name comes from the Latin torpere, to be stiffened or paralyzed, referring to the effect on someone who handles or steps on a living electric ray (Martin, 2008).
2.1.5.3.1. Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Chondrichthyes Subclass: Elasmobranchii Superorder: Batoidea Order: Torpediniformes, (Froese and Daniel, 2011)
27
Plate (4): Lesser electric ray (Narcine bancroftii) Source: (Hamlett, 1999)
28
2.1.5.3.2. Description Electric rays have a rounded pectoral disc with two moderately large rounded- angular (not pointed or hooked) dorsal fins (reduced in some narkids), and a stout, muscular tail with a well-developed caudal fin. The body is thick and flabby, with soft, loose skin devoid of dermal denticles and thorns. A pair of kidney-shaped electric organs are found at the base of the pectoral fins. The snout is broad, large in the Narcinidae, but reduced in all other families. The mouth, nostrils, and five pairs of gill slits are located underneath the disc (Hamlett, 1999). Electric rays are found from shallow coastal waters down to at least 1,000 m (3,300 ft) deep. They are sluggish and slow-moving, propelling themselves with their tails, rather than using their disc-shaped bodies, as other rays do. They feed on invertebrates and small fish. They lie in wait for prey below the sand or other substrate, using their electricity to stun and capture it (Stevens and Last, 1998).
(قشري) Grouper .2.1.5.4 Groupers are fish (Plate, 5) of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called groupers; the family also includes the sea basses. The common name grouper is usually given to fish in one of two large genera: Epinephelus and Mycteroperca. In addition, the species classified in the small genera Anyperidon, Cromileptes, Dermatolepis, Gracila, Saloptia, and Triso are also called groupers. Fish in the genus Plectropomus are referred to as coralgroupers. These genera are all classified in the subfamily Epiphelinae. However, some of the hamlets (genus Alphestes), the hinds (genus Cephalopholis), the lyretails (genus Variola) and some other small genera (Gonioplectrus, Niphon, Paranthias) are also in this subfamily, and occasional species in other serranid genera have common names involving the word "grouper". Nonetheless, the word "grouper" on its own is usually taken as meaning the subfamily Epinephelinae. The word "grouper" is most widely believed to be from the Portuguese name, garoupa. The origin of this name in Portuguese is believed to be from an indigenous South American language (Hāpuku, 2009; Lieske and Myers, 1999).
29
Plate (5) Malabar grouper, Epinephelus malabaricus Source: (Hāpuku, 2009)
30
2.1.5.4.1. Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Perciformes Family: Serranidae Subfamily: Epinephelinae, (Hāpuku, 2009)
In Australia, "groper" is used instead of "grouper" for several species, such as the Queensland grouper (Epinephelus lanceolatus). In the Philippines, it is named lapu-lapu in Luzon, while in the Visayas and Mindanao it goes by the name pugapo. In New Zealand, "groper" refers to a type of wreckfish, Polyprion oxygeneios, which goes by the Māori name hāpuku. In the Middle East, the fish is known as hammour, and is widely eaten, especially in the Persian Gulf region (Erisman et al., 2009). 2.1.5.4.2. Description Groupers are teleosts, typically having a stout body and a large mouth. They are not built for long-distance, fast swimming. They can be quite large, and lengths over a meter and weights up to 100 kg are not uncommon, though obviously in such a large group, species vary considerably (DeMartini et al., 2011; Allsop and West, 2003). They swallow prey rather than biting pieces off it. They do not have many teeth on the edges of their jaws, but they have heavy crushing tooth plates inside the pharynx. They habitually eat fish, octopuses, and crustaceans. Some species prefer to ambush their prey, while other species are active predators. Reports of fatal attacks on humans by the largest species, the giant grouper (Epinephelus lanceolatus) are unconfirmed (Heather and Houston, 2014). Their mouths and gills form a powerful sucking system that sucks their prey in from a distance. They also use their mouths to dig into sand to form their shelters under big rocks, jetting it out through their gills. Research indicates roving coralgroupers (Plectropomus pessuliferus) sometimes cooperate with giant morays in hunting (Heather and Houston, 2014).
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(الشعري) Lethrinus nebulosus .2.1.5.5
2.1.5.5.1. Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Perciformes Family: Lethrinidae Genus: Lethrinus Species: nebulosus, WoRMS (2014).
Lethrinus nebulosus (Plate, 6) is a species of emperor fish. Common names include spangled emperor, green snapper, morwong, north-west snapper, sand bream, sand snapper, sixteen-pounder, and yellow sweetlip (WoRMS, 2014). 2.1.5.5.2. Description This species is commonly found at approximately 87 cm in length, but grows to 70 cm. It is yellow to yellowish-brown or bronze in colour, the belly being lighter. It has scattered blue markings over the body. The cheeks have no scales and may have a vertical blue markings. It has whitish or yellowish fins with a yellowish-edged dorsal fin (WoRMS, 2014). This fish occurs in the waters of East Africa to the southern parts of Japan. It also lives in Australian coastal waters, and has been recorded in the Red Sea, Persian Gulf and New Caledonia (Fricke et al., 2011; Justine et al., 2010), where it is one of the major commercial fish. Lethrinus nebulosus inhabits both marine and brackish waters at depths of between 10 and 75 meters. It is a non-migratory species (Rascalou and Justine, 2007), and is found on coral and rocky reefs, sea-grass beds, mangrove swamps, as well as over sandy substrates. Juveniles may be found in large schools (Laboute and Grandperrin, 2000).
32
Plate (6) Lethrinus nebulosus fish Source: WoRMS (2014
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(عربي) Mullet .2.1.5.6 The mullets (Plate, 7) or grey mullets are a family (Mugilidae) and order of ray-finned fish found worldwide in coastal temperate and tropical waters, and in some species in fresh water. Mullets have served as an important source of food in Mediterranean Europe since Roman times. The family includes about 80 (at least 73) species in 17 genera, although half of the species are in just two genera (Liza and Mugil). Mullets are distinguished by the presence of two separate dorsal fins, small triangular mouths, and the absence of a lateral line organ. They feed on detritus, and most species have unusually muscular stomachs and a complex pharynx to help in digestion (Johnson and Gill, 1998).
2.1.5.6.1. Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Mugiliformes Family: Mugilidae, Johnson and Gill, (1998)
Taxonomically, the family is currently treated as the sole member of the order Mugiliformes. The presence of fin spines clearly indicates membership in the superorder Acanthopterygii, and in the 1960s, they were classed as primitive perciforms, while others have grouped them in Atheriniformes (Gosline, 1961). In North America, "mullet" by itself usually refers to Mugilidae. In Europe, the word "mullet" is usually qualified, the "grey mullets" being Mugilidae and the "red mullets" or "surmullets" being Mullidae, notably members of the genus Mullus, the red mullets. Outside Europe, the Mullidae are often called "goatfish". Fish with common names including the word "mullet" may be a member of one family or the other, or even unrelated such as the freshwater white sucker (Catostomus commersonii) (Froese and Daniel, 2012; Sepkoski, 2002).
34
Plate (7) Mullet (Mugil cephalus) fish Source: (Johnson and Gill, 1998).
35
(البياض البحري) Sander Sander lucioperca .2.1.5.7 2.1.5.7.1. Scientific classification Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Actinopterygii Order: Perciformes Family: Percidae Genus: Sander Species: lucioperca (Fuller, 2011)
2.1.5.7.2. Description S. lucioperca (Plate, 8) has a long slender body. There are no spines on the gill cover. The mouth has many small teeth and fewer large teeth for catching the prey. The species has two dorsal fins – one with 13 to 20 spines and one with 1-2 spines and 18 to 24 soft rays. The caudal fin has 17 soft rays and the anal fin has 2-3 spines and 10-14 soft rays.” “S. lucioperca obtains a maximum length of 100-130 cm which corresponds to a weight of about 15-20 kg. Maximum age is inversely correlated to growth rate. Slow-growing S. lucioperca in the northern part of the distribution area reach 20-24 years of age, while faster-growing S. lucioperca in the southern part only reach about 8-9 years (Fuller, 2011).
36
Plate (8) Sander (S. lucioperca) fish Source: Fuller (2011)
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(السلماني) (The milkfish (Chanos chanos .2.1.5.8 2.1.5.8.1. Scientific classification
Kingdom: Animalia Phylum: Chordata Order: Gonorynchiformes Family: Chanidae Genus: Chanos Species: chanos, (Eschmeyer, and Fricke, 2016) The milkfish (Chanos chanos) is the sole living species in the family Chanidae. However, there are at least five extinct genera from the Cretaceous. The species has many common names. The Hawaiian name for the fish is awa. It is called bangús in the Philippines, where it is the national fish. In the Nauruan language, it is referred to as ibiya. Milkfish is also called "bandeng" or "bolu" in Indonesia (Eschmeyer and Fricke, 2016; Froese and Daniel, 2015; Nelson, 2006). 2.1.5.8.2. Description and biology The milkfish (Plate, 9) has a generally symmetrical and stream lined appearance, with a sizable forked caudal fin. They can grow to 1.80 m, but are most often no more than 1 m (39 in) in length. They have no teeth and generally feed on algae and invertebrates. They occur in the Indian Ocean and across the Pacific Ocean, tending to school around coasts and islands with reefs. The young fry live at sea for two to three weeks and then migrate to mangrove swamps, estuaries, and sometimes lakes, and return to sea to mature sexually and reproduce. The milkfish is an important seafood in Southeast Asia and some Pacific Islands. Because milkfish is notorious for being much bonier than other food fish, deboned milkfish, in the Philippines, has become popular in stores and markets (Froese and Pauly, 2015). Another popular presentation of milkfish in Indonesia is bandeng duri lunak or bandeng presto (ikan bandeng is the Indonesian name for milkfish) from Central and East Java. Bandeng presto is pressure cooked milkfish until the bones are rendered tender. Another way to prepare milkfish is bandeng asap or smoked milkfish. Either fresh or processed, milkfish is the popular seafood product of Indonesian fishing towns, such as Juwana near Semarang in Central Java, and Sidoarjo near Surabaya in East Java (Froese and Pauly, 2015).
38
Plate (9) The milkfish (Chanos chanos) Source: (Froese and Pauly, 2015)
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CHAPTER THREE MATERIALS AND METHODS
3.1 Sampling of Materials: Eight fish types were brought from the local fishes market, at October 2014,
,(نابليون) from Port Sudan, Red Sea State, Sudan. The samples of {Humphead wrasse
,(الشعري) Lethrinus ,(قشري) Grouper ,(الرعاد) Electric ray , ,(الدنيس) Gilt-head bream
were selected as raw {(السلماني) and the milkfish ,(البياض البحري) Sander ,(عربي) Mullet materials for this study. These fishes are the most popular types in Port Sudan city.
3.2 Methods The fish samples were cleaned, cut from internal abdominal parts , then prepared to carry out the mineral contents that done in the Laboratory of Chemistry, Customhouse Laboratory, Port Sudan. Then the same samples were brought by refrigerator to the Laboratory of Food Analysis, Faculty of Engineering and Technology, University of Gezira, to test approximate tests. 3.2.1 Moisture content Moisture content was carried out according to AACC (1983), whereby, 5 g of fish meat samples were weighed into a pre-dried, clean weighed porcelain dish. The samples were then placed in an air oven adjusted to 130oC for 3 hours; the samples were then removed from the oven, and cooled in a desiccators at room temperature and weighed. Moisture and dry matter (D.M) content were calculated according to the following formula: 푙표푠푠 표푓 푤푒𝑖푔ℎ푡 ×100 Moisture content = 푤푒𝑖푔ℎ푡 표푓 푠푎푚푝푙푒 D.M = 100- moisture%. 3.2.2 Ash content The various samples were analyzed for their ash content by the procedure described by AOCS (1985). 5 g of each samples were weighed into previously heated, pre-dried and pre-weighed crucible. These crucibles with its contents were then placed in muffle furnace at 550oC and maintained at this temperature for 5 hours. The
40 crucibles were then transferred to desiccator, cooled at room temperature and reweighed. Ash content was then calculated on dry matter basis as follows: (푏−푎) 100 Ash % = × 푀 (100−퐹) Where: a = weight of empty dish. b = weight of dish with Ash. M = weight of fish meat sample (g). F = moisture content of the sample.
3.2.3 Oil content Oil contents of the various samples were determined according to AOCS (1985). In this method, 3 g of fish meat sample were weighed into filter paper folded in such a way so as to prevent escape of the meal and then placed inside the thimble. Apiece of absorbent cotton was placed on the top of thimble to distribute the solvent as it drops on the sample. The thimble with the wrapped sample was then placed in the extraction tube of the soxhlet and then 150 ml of n-hexane (99% purity) were poured in the extraction flask before fixing the tubes, after 6 hours of extraction the extraction flasks was disconnected. The hexane was recovered by distillation under the vacuum. Last traces of hexane where removed by putting the flask in the oven. The flasks were then cooled at room temperature in desiccator and weighed. Oil content was calculated as follows: 푤푒𝑖푔ℎ푡 표푓 표𝑖푙 ×100 Oil% = 푤푒𝑖푔ℎ푡 표푓 푠푎푚푝푙푒 3.2.4. Protein content Protein content of each fish meat sample was determined according to AACC (1983) in which one gram sample was digested using 25 ml of concentrated sulfuric acid for 6 hours. Then the digested sample was transferred to 100 ml volumetric flask. Five ml of the clean digested sample were pipette into distillation unit and then 10 ml of 40% NaOH were poured in the funnel. The ammonia trapped in boric acid (2%) was titrated against 0.1 N HCL solution, a faint pink color was taken as end point. The protein percentage was calculated as follows:
푚푙 표푓 0.1푁 퐻퐶퐿 ×0.014 ×6.25 ×100 Crude protein % = 푤푒𝑖푔ℎ푡 표푓 푠푎푚푝푙푒
41
3.2.6 Carbohydrate content Carbohydrate contents were obtained by subtraction. % Carbohydrate Content = 100 - (protein% + oil% +Fiber%+ ash% + moisture %) 3.2.7. Mineral contents Determination of minerals done by minerals reading device (commercial name: X-met 5000 (XAF) in the Laboratory of Chemistry, Customhouses Laboratory, Port- Sudan. Three g sample ash were read by (XAF) to determine the minerals present in sample as percent of ash then minerals% calculated as follow: (푤푒𝑖푔ℎ푡 표푓 푎푠ℎ) Mineral weight (mg/100g) = (mineral %) x 100 3.3 Statistical analysis Microsoft office, using the tools of Simple descriptive statistic and ANOVA two factors without replication test were used to describe the observed variations between the samples of fish meat used.
42
CHAPTER FOUR RESULTS AND DISCUSSION 4.1 Nutritional values of the selected fishes Table (4.1) showed that, all types of fishes contain few carbohydrates in their meat samples as follows: Electric ray ( 3,6%), Milkfish (2,38%) , Sander lucioperca (2,11%), Gilt-head bream and Grouper (0,98%), Lethrinus nebulousus (0,79%), Mullet (0.76%) . it was found that, the moisture content was as follows: Sander lucioperca and Lethrinus nebulosus contain highest amount (70.64%), Grouper (70.35%), Gilt-head bream (70.19%), Mullet (70.12%), Electric ray (70.08%), Milkfish (69.60%) and finally, Humphead wrasse (66.06). Ash content (the inorganic constituents) was as follows: Mullet (2.79%), Electric ray (2.46%), Sander lucioperca (2.23%), Humphead wrasse (1.88%), Milkfish (1.79%), Gilt-head bream (1.67%), Lethrinus nebulousus (1.47%) and in Grouper (1.45%). Protein content in Gilt-head bream (15.89%), Humphead wrasse (15.09%), Lethrinus nebulosus (14.96%), Grouper (14.19%), Sander lucioperca (13.44%), Electric ray (12.84%), Milkfish (12.04%) and at the last rank, in Mullet (9.97). Fat content as an important nutrient part (because of its content of fat-soluble vitamins and omega-3 fatty acids), showed variant values: the highest fat content was in the meats of Humphead wrasse (16.0%), followed by Mullet (15.80%), Milkfish (13.33%), Grouper (12.46%), Lethrinus nebulosus (11.66%), Sander lucioperca (11.14%), Gilt-head bream (10.67), Electric ray (10.33) at last. Fat is the only source of omega-3 fatty acids that has many health benefits such as reducing risks of heart disease, cancer and depression (Belury, 2011). It was clear that, moisture content was the most abundant constituents in fish meats (mean 69.71%), followed by protein (mean 13.55%), fat (mean 12.67%), ash (mean 1.97%) and at last carbohydrate (mean 1.54%). Ala Eldeen (1994) stated that, protein ranged between 15% and 24% and fat between 1% and 22%, which agreed with the values obtained in this study. ANOVA proved that, there was no significant differences between the tested fish meat samples in their proximate contents (f= 0.08; f-crit= 2.29), i.e. they were similar in the quantities of their proximate contents (total 100%), irrespective of their quality.
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Table ( 4.1 ) Proximate values of the meats of the selected fishes
Species Protein Ash moisture Fat CHO Humphead 15.09 1.88 66.06 16.0 0.68 Gilt-head bream 15.89 1.67 70.19 10.67 0.98 Electric ray 12.84 2.46 70.08 10.33 3.6 Grouper 14.19 1.45 70.35 12.46 0.98 Lethrinus nebulosus 14.96 1.47 70.64 11.66 0.79 Mullet 9.97 2.79 70.12 15.80 0.76 Sander 13.44 2.23 70.64 11.14 2.11 Milk fish 12.04 1.79 69.60 13.33 2.38
Variance Average Sum Count SUMMARY 3.693936 13.5525 108.42 8 Protein 0.232993 1.9675 15.74 8 Ash 2.287057 69.71 557.68 8 moisture 4.885998 12.67375 101.39 8 Fat 1.115943 1.535 12.28 8 CHO
ANOVA F crit P-value F MS df SS Source 2.35926 1 0.001893 0.00578 7 0.040458 Rows 2.714076 2.65E-34 2117.84 6464.785 4 25859.14 Columns 3.052537 28 85.47103 Error
39 25944.65 Total
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4.2 The detected elements in the tested fishes Table 4.2 showed the detected elements (per mg/100 g fish meat) in the tested fishes. Potassium (K) content ranged between 14.7 (mg/100g; the least value) in Lethrinus nebulosus fish meat, and 20.2 (mg/100g; the higher value) in Grouper fish meat, whereas, it was detected in the rest of the fish meat as follow: Mullet (19.6), Gill-head bream and Milkfish the same value (17.5), Sander lucioperca (16.6), Electric ray (15.9) and Humphead wrasse (15). Calcium (Ca) content is ranged between 1.1 (mg/100g; the least value) in Lethrinus nebulosus fish meat, and 12.3 (mg/100g; the higher value) in Humphead fish meat, whereas, it was detected in the rest of the fish meat as follow: Mullet (3.5), Sander lucioperca (2.1), Milkfish (2), Grouper (1.5), Electric ray (1.4) and Gilt-head bream (1.3). Barium (Ba) content is ranged between 0.0 (mg/100g; the least value) in Lethrinus nebulosus, Gilt-head bream, Grouper and Milk fish meats, and 0.1 (mg/100g; the higher value) in the rest fish meat (Gilt-head bream, Lethrinus nebulosus, Milkfish and Grouper). Iron (Fe) content is not detected in all fish meats. The total element content (in term of mg/100 g) showed considerable variations among the tested fish meats, e.g. in Humphead fish meat, the sum of K, Ca, Ba and Fe was 27.4 (mg/100 g; the higher value), followed by Mullet (23.2 mg/100 g), and Grouper (21.7 mg/100 g), whereas, Electric fish (17.4 mg/100 g) and Lethrinus nebulosus (15.8 mg/100 g) have the fewer sum of element contents. And since that, ash is completely made of mineral elements, the unseen quantities (total amount minus sum of K, Ca, Ba and Fe), were referred completely to the other undetected elements (e.g P, Na and Bo). The reasons for the variations in proximate and mineral contents may be due to the gender, age, physiological status and the time and location of fishing, as was suggested by Mazen (1983). ANOFA proved that, there was a significant differences between the tested fish meat samples in their mineral contents (f= 107.55; f-crit= 3.07), i.e. they were not similar in the quantities of their element contents (specially, K, Ca, Ba and Fe).
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Table (4.2) The element contents (mg/100 g) in the meats of the selected fishes
Species K Ca Ba Fe Humphead 15 12.3 0.1 0 Gilt-head bream 17.5 1.3 0 0 Electric ray 15.9 1.4 0.1 0 Grouper 20.2 1.5 0 0 Lethrinus nebulosus 14.7 1.1 0 0 Mullet 19.6 3.5 0.1 0 Sander 16.6 2.1 0.1 0 Milk fish 17.5 2 0 0
Variance Average Sum Count SUMMARY 62.87 6.85 27.4 4 Humphead 73.19 4.7 18.8 4 Gilt-head bream 59.7 4.35 17.4 4 Electric ray 97.52 5.43 21.7 4 Grouper 51.63 3.95 15.8 4 Lethrinus nebulosus 87.29 5.8 23.2 4 Mullet 63.87 4.7 18.8 4 Sander 71.73 4.88 19.5 4 Milk fish
4.0 1 17.1 3 137 8 K 14.24 3.15 25.2 8 Ca 0.003 0.05 0.4 8 Ba 0 0 0 8 Fe
ANOVA F crit P-value F MS df SS Source 2.49 0.686169 0.68 3.38 7 23.64 Rows 3.07 6.6E-13 107.55 533.10 3 1599.31 Columns 4.96 21 104.09 Error
31 1727.0 5 Total
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CHAPTER FIVE CONCLUSIONS AND RECOMMENDATIONS 5.1 Conclusions 1- Concerning proximate contents: carbohydrates were ranged between0.68% in Hump head and 3.6% in Electric ray . Fat content is ranged between 10.33% (the least value) in Electric ray fish meat, and 16% (the higher value) in Hump head fish meat. Protein content is ranged between 66.06% (the least value) in Hump head fish meat, and 70.64% (the higher value) in Sander fish meat. Fiber content is ranged between 0.29% (the least value) in Hump head fish meat, and 0.86% (the higher value) in Milk fish meat. Ash content is ranged between 1.45% (the least value) in Grouper fish meat, and 2.79% (the higher value) in Mullet fish meat. Moisture content is ranged between 9.97% (the least value) in Mullet fish meat, and 15.89% (the higher value) in Gilt-head bream fish meat. 2- Concerning mineral contents: Potassium (K) content is ranged between 14.7 (mg/100g) in Lethrinus nebulosus fish meat, and 20.2 (mg/100g) in Grouper fish meat. Calcium (Ca) content is ranged between 1.1 (mg/100g) in Lethrinus nebulosus fish meat, and 12.3 (mg/100g) in Humphead fish meat. Barium (Ba) content is ranged between 0.0 and 0.1 (mg/100g), whereas, Fe is not detected in all fish meats. 3- Anova proved no significant differences between fish meat samples in their proximate contents, while it proved a significant differences in their mineral contents.
5.2 Recommendations 1- Some aware must be given to the people concerning the nutritional culture towards fish meat because of its potential health benefits. 2- Fish meat consumption should be enhanced and do not relay ultimately on the red meat. 3- Further studies should be run on fish and fish products such as omega-3 fatty acids as medical supplements.
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REFERENCES
AACC (1983). Approved methods of the American Association of Cereal Chemist, 8th ed. The association: St. Paul, MN Abdul Hamid, M. (1994). Principal of fish production. M.Sc. thesis, University of Khartoum. Aladin, M. (1994). Animal met health, Al Riad, KSC, stated by :Abd Alrahem Ahmed Mohamed (Lecture notes). Alan, D. (1972). Mediterranean Seafood, Penguin, 1972. ISBN 0-14-046174-4, pp. 86–108. Allsop, D. J. and West, S. A. (2003). Constant relative age and size at sex change for sequentially hermaphroditic fish. Journal of Evolutionary Biology, 16:921-929. Anthony, K. R. N. (2008). Ocean Acidification causes bleaching and productivity loss in coral reef builders. PNAS, 105: 17442–17446. AOCS (1985). Official Methods and recommended practices of the American Oil Chemist΄ Society. 3rd Ed. (1985) Vol 1. Belury, M. A. (2011). The Omega-3 Fatty Acid Composition and Cost Analysis of Fish Oil Supplements: Fishing for the Best Deals. A Senior Honors Thesis. The Ohio State University, USA Chateau, O. and Lantiez, L. (2007). Site fidelity and activity patterns of a Humphead wrasse, Cheilinus undulatus (Labridae), as determined by acoustic telemetry. Environmental Biology of Fishes, 80 (4): 503–508. Chateau, W. (2007). Site fidelity and activity patterns of a humphead wrasse, Cheilinus undulatus (Labridae), as determined by acoustic telemetry. Environmental Biology of Fishes (Springer Netherlands). Daley, A. (1994). Shark. Hodder and Stroughton. ISBN 0-340-61654-7. DeMartini, E. E.; Everson, A. R. and Nichols, R. S. (2011). Estimates of body sizes at maturation and at sex change, and the spawning seasonality and sex ratio of the endemic Hawaiian grouper (Hyporthodus quernus, f. Epinephelidae). Fishery Bulletin, 109:123-134. Erisman, B. E.; Craig, M. T. and Hastings, P. A. (2009). A phylogenetic test of the size-advantage model: Evolutionary changes in mating behavior influence
48
the loss of sex change in a fish lineage. American Naturalist, 174:83-99. Eschmeyer, W. N. and Fong, J D. (2013). "Catalog of Fishes". California Academy of Sciences. Eschmeyer, W. N. and Fricke, R. (eds) (2016). "Catalog of Fishes". California Academy of Sciences. Retrieved 25 January 2016. Ewald, L. and Robert, M. (2004). Coral Reef Guide: Red Sea. Collins, 384 Pages, Paperback. FAO, Food and Agriculture Organization (2011). Yearbook of fishery and aquaculture statistics 2009. Capture production (PDF). Rome: FAO. pp. 163. Fricke, R.; Kulbicki, M. and Wantiez, L. (2011). Checklist of the fishes of New Caledonia, and their distribution in the Southwest Pacific Ocean (Pisces). Stuttgarter Beitraege zur Naturkunde Serie A (Biologie), 4: 341–463. Froese, R. and Daniel, P. eds. (2011). "Torpediniformes" in FishBase.Generic harvest control rules for European fisheries .Fish Fish 12:340 – 351. Froese, R. and Daniel, P. eds. (2012). "Mugilidae" in FishBase. Froese, R. and Daniel, P. eds. (2015). "Chanidae" in FishBase.Rebuilding fish stocks : will Europe meet the deadline? Fish Fish 11: 194 -202. Froese, R. and Pauly, D. eds. (2007). "Synanceia verrucosa" in Fish Base.
Froese, R. and Pauly, D. eds. (2015). "Chanos chanos" in FishBase. Environ Biol.Fish 39 ( 1) : 23-41 . Froese, R. and Pauly, D., eds. (2010). "Sparus aurata" in FishBase.Fish Fish 13:67- 79. Fuller, A. (2011). Stocked for sport fishing: Sander lucioperca. Ecological Risk Screening Summary U.S. Fish and Wildlife Service. Gok, A. (2005). Fisheries Annual Statistics. Ministry of Agriculture/Private Sector Development in Agriculture (PSDA), Annual bulletin , Kenya. Gosline, W. A. (1961). The Perciform Caudal Skeleton" Copeia, 1961(3): pp. 265- 270. Hamlett, W. C. (1999). Sharks, Skates, and Rays: The Biology of Elasmobranch Fishes. Baltimore and London: JHU Press. Hāpuku, T. A. (2009). "Coastal fish - Encyclopedia of New Zealand". Teara.govt.nz.
49
Heather, A. and Houston, C. (2014). "Gulf grouper swallows 4 foot shark in a single bite". Houston Chronicle- Florida. Helfman, G.; Collette, B. and Facey, D. (1997). The Diversity of Fishes (1st ed.). Wiley-Blackwell. Helfman, G.; Collette, B.; Facey, D. and Bowen, B. (2009). The Diversity of Fishes: Biology, Evolution, and Ecology (2nd ed.). Wiley-Blackwell. Janet, M.; Torpy, C. L. and Richard, M. G. (2006). Eating Fish: Health Benefits and Risks. JAM, 296(15):1926. Johnson, G. D. and Gill, A. C. (1998). Encyclopedia of Fishes. Paxton, J.R. and Eschmeyer, W.N., ed. San Diego, Academic Press. pp. 192. Justine, J. L.; Beveridge, I.; Boxshall, G. A.; Bray, R. A.; Moravec, F. and Whittington, I. D. (2010). An annotated list of fish parasites (Copepoda, Monogenea, Digenea, Cestoda and Nematoda) collected from Emperors and Emperor Bream (Lethrinidae) in New Caledonia further highlights parasite biodiversity estimates on coral reef fish. Zootaxa, 2691, 1-40. Laboute, P. and Grandperrin, R. (2000). Poissons de Nouvelle-Calédonie. Nouméa, New Caledonia: Éditions Catherine Ledru. Lieske, E. and Myers, R. (1999). Coral Reef Fishes. 2nd edition. ISBN 0-691- 02659-9. Lieske, E. and Myers, R. F. (2004). Coral reef guide; Red Sea London, Harper Collins ISBN 0-00-715986-2 Martin, R. A. (2008). Electric Rays. Reef Quest Centre for Shark Research. Retrieved on October 12, 2008. Moyle, P. B. (1993). Fish: An Enthusiast's Guide University of California Press. ISBN 9780520916654 – good lay text. Moyle, P. B. and Cech, J. J. (2003). Fishes, An Introduction to Ichthyology (5th ed.). Benjamin Cummings. ISBN 978-0-13-100847-2. Nelson, J. S. (2006). Fishes of the World (4 ed.). Hoboken, NJ: John Wiley and Sons. p. 135–136. ISBN 978-0-471-25031-9. OOsman, A. (2012). Biomarkers in Nile Tilapia Oreochromis niloticus niloticus (Linnaeus, 1758) to Assess the Impacts of River Nile Pollution: Bioaccumulation, Biochemical and Tissues Biomarkers, Journal of Environmental Protection, 3(8A): 966-977.
50
Randall, J. E. (1978). "Food habits of the giant humphead wrasse, Cheilinus undulatus (Labridae)". Environmental Biology of Fishes, 3: 235–238. Rascalou, G. and Justine, J. L. (2007). Three species of Calydiscoides (Monogenea: Diplectanidae) from five Lethrinus spp. (Lethrinidae: Perciformes) off New Caledonia, with a description of Calydiscoides terpsichore sp. n. Folia Parasitologica, 54, 191-202. Russell, B. (2004). Grouper and Wrasse Specialist Group. Cheilinus undulatus. In: IUCN 2013. IUCN Red List of Threatened Species-
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