Fish Physiology

Kojic acid (5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one) is a common contaminant of many food products which are part of humans or animals daily nutrition (sake, soy sauce, cereals, fodder and dairy products). This mycotoxin has demonstrated antibacterial, antifungal, antiparasitic, insecticide, antioxidant and skin whitening effects. In this study, adult zebrafish were divided in 4 groups: Control and 3 kojic acid-treated groups which were exposed to 100 mg/l, 204 mg/l and 284 mg/l kojic acid for 7 days. Histological alterations of the control and kojic acid-treated group were examined and compared, with emphasis on liver, kidney, pancreas, intestine, brain and myocardium. While the Control group had no histological alterations, the kojic acid-exposed zebrafish show hepatocytes hyperhydration/vacuolation, fragmentation of the cell membrane, nuclear karyolysis/pycnosis, a significant shortening of the intestinal villi, myocardiocytes degeneration, a moderatesevere myocardial congestion, an important lipid infiltration of the exocrine pancreas leading to the atrophy of the acini, nephrocyte degeneration and hyalinosis, nuclear hyperhydration, reduction to annulation of the tubular lumens. The histological alterations increase proportionally with the kojic acid dose.

An elastic longitudinal ligament stretched under considerable tension lies within the dorsal aorta of Rainbow trout.Experiments with mechanically simulated swimming movements in an artificial model demonstrate that such a ligament can act as a pump mechanism. The output of the pump increases with tail beat frequency up to a certain point where the mechanism tends to break down. Investigations on the trout dorsal aorta show that pump breakdown probably takes place at relatively low output pressures.Fundamental blood flow considerations indicate that a fully effective dorsal aorta pump over the full range of swimming speeds is undesirable. It is concluded that the dorsal aorta ligament can act as a pump which automatically increases circulation during swimming particularly to the body musculature. The output pressure is small but may be of significance in causing reflex increase in cardiac output.

The effect of the sublethal concentration of (3.75x104 mgl) on the activities of hexokinase, lactate dehydrogenas and pyruvate dehydrogenase in liver. Gill and muscle of a fresh water carp, Cyprinus carpio fingerlings studied at the intervals of 15 and 30 days. Fingerlings exposed to 30 days showed remarkable alterations in the activities of enzymes than the fingerlings exposed to 15 days. The activities of all three enzymes were decreased in liver and muscle. Whereas in gill the activities of hexokinase increased and other two enzymes decreased.

The aim of this study was to evaluate the oocytes, post-fertilization events and embryonic development in Brycon insignis, under both scanning electron microscopy and stereomicroscopy. Oocytes and embryos were sampled from spawning up to hatching. Stripped oocytes were spherical, non-adhesive, greenish-brown, possessed a single micropyle, pore-canals and had a mean diameter of 1.46 mm. In 63% of oocytes the germinal vesicle was peripheric. The main post-fertilization events were the fertilization cone formation (20 s), micropyle closure (100–180 s) and agglutination of supernumerary spermatozoa (100–180 s). Embryonic development lasted 30 h at ~24 °C and was characterized by seven stages. Zygote, cleavage, blastula and gastrula stages were first observed at 0.25, 1, 3 and 6 h post-fertilization, respectively. Fertilization rate was determined at the moment of blastopore closure, 10–11 h post-fertilization. The segmentation stage began at 11 h post-fertilization and comprised the development of somites, notochord, optic, otic and Kupffer's vesicles, neural tube, primitive intestine, and development and release of the tail. The larval stage began 21 h post-fertilization and was characterized by the presence of somites, growth and elongation of the larvae. At the hatching stage, embryos presented vigorous contractions of the tail and body leading to chorion rupture (30 h). The morphological characteristics described for B. insignis were similar to that described for other teleost species, and such knowledge is important for a better understanding of reproductive features of a species and useful for ecological and conservational studies.

Photoperiod effect on Growth parameters and cannibalism of  Clarias gariepinus have been well
documented in resent past, but little is known about the response of other biological parameters
such  as,  Condition  factor,  Shooters  composition,  Body  colouration  and  Blood  glucose  of  this
important tropical fish species to different photoperiods, therefore the present study was designed
to evaluate these responses  of the African catfish to 24 hours of light (00D:24L), 24 hours of
darkness (24D: 00L) and 12 hour light / 12 hours darkness (12D: 12L). The six weeks experiment
observed  significant  differences  (P<0.05)  in  weight  gain  of  the  fish  reared  at  the  different
photoperiods with the highest value of 92.20g+1.10 obtained in fishes reared under a photoperiod
of twenty-four hours of darkness (24D: 00L) compared to those reared under a photoperiod of
twelve hours of light and twelve hours of darkness (12D: 12L) which had 69.80g+2.50 and the least
weight gain of 59.50g+8.2 was obtained under a twenty four hours of light (00D: 24L) photoperiod.
Despite the stress induced by light which affected the weight gain of the fish, condition factor of
the  fishes  in  the  different  photoperiods  did  not  vary  significantly  (P>0.05)  at  the  end  of  the
experiment  and  were  Significantly  lower  than  value  obtained  at  the  start  of  the  experiment,
Shooters  composition  was  highest  in  00D:24L  (41.5%  i.e.  27  of  65)  leading  to  high  mortality
(13.33%) due to cannibalism  compared to 12D: 12L (Shooters =15.27% i.e. 11 of 72, Mortality= 4%)
and 24D: 00L (Shooters=5.33% i.e. 4 of 75, Mortality= 0%) photoperiod. More so, 93.33% (70 of 75)
of fish in the dark phase (24D: 00L) exhibited Deep shiny black body colouration, while 6.67% (5 of
75) was observed of Normal fish colouration. However the fishes in the 00D: 24L photoperiod were
observed to be predominantly Lighter skin colouration, (80% i.e. 52 of 65= lighter colouration,
18.46% i.e. 12 of 65= Normal skin coloration and 1.53 i.e. 1 of 65= Deep black body colouration)
while 12D: 12L were of Normal skin colouration (100% Normal skin colouration), also blood glucose
was observed to increase as the light hours increased (P<0.05) with 24D: 00L photoperiod having
the highest blood glucose level of 5.7+0.5, while those in 12D: 12L had 4.4+0.3 and 24D: 00L had
the least value of 3.9+0.1. This study therefore establishes the fact that photoperiod may have no
effect on the condition factor of African catfish, while higher shooters composition is highlighted as
one of the causes of increased mortality and could be reduced to a large extent with reduced light
phase therefore enhancing higher survival, also the use of blood glucose as an indicator of stress in
fish was justified in the present study.

There are a small number of fish species, both marine and freshwater, that exhibit a truly amphibious habit that includes periods of aerial exposure. The duration of emersion is reflected in the level of physical and physiological adaptation to an amphibious lifestyle. Fish that are only briefly out of water retain predominantly aquatic attributes whereas there are semi-terrestrial species that are highly adapted to prolonged periods in the aerial habitat. Desiccation is the main stressor for amphibious fish and it cannot be prevented by physiological means. Instead, amphibious fish resist excessive water loss by means of cutaneous modification and behavioural response. The more terrestrially adapted fish species can tolerate considerable water loss and may employ evaporation to aid thermoregulation. The amphibious habit is limited to fish species that can respire aerially. Aerial respiration is usually achieved through modification to existing aquatic pathways. Freshwater air-breathers may respire via the skin or gills but some also have specialized branchial diverticula. Marine species utilize a range of adaptations that may include modified gills, specialized buccopharyngeal epithelia, the intestine and the skin. Areas of enhanced respiratory activity are typified by increased vascularization that permits enhanced perfusion during aerial exposure. As with other adaptations the mode of nitrogenous elimination is related to the typical durations of emersion experienced by the fish. Intertidal species exposed on a regular cycle, and which may retain some contact with water, tend to remain ammoniotelic while reducing excretion rates in order to prevent excessive water loss. Amphibious fish that inhabit environments where emersion is less predictable than the intertidal, can store nitrogen during the state of emersion with some conversion to ureotelism or have been shown to tolerate high ammonia levels in the blood. Finally, the more amphibious fish are more adapted to moving on land and seeing in air. Structural modifications to the pectoral, pelvic, dorsal and anal fins, combined with a well-developed musculature permit effective support and movement on land. For vision in air, there is a general trend for fish to possess close-set, moveable, protruberant eyes set high on the head with various physical adaptations to the structure of the eye to allow for accurate vision in both air and water.

There is a developing interest in Hemibagrus nemurus culture. Most hatcheries depend on fry from the wild, which is under threat due to human activities. Hatchery production of H. nemurus is not well established due to problems associated with artificial propagation. Good egg quality is essential for fry production. This paper reports the findings of research conducted to determine the effects of mammalian gonadotropin releasing hormone analogue (GnRHa) and ovaprim on induced spawning performance and egg quality of H. nemurus. Mature female H. nemurus were treated with 0.5ml of 0.7% NaCl (control), 5μg/kg, 20μg/kg, 50μg/kg body weight (BW) of fish GnRHa and 0.5ml/kg BW of fish of ovaprim (20μg/ml sGnRHa and 10mg/ml domperidone). The results showed that the administration of 5μg/kg BW GnRHa is not sufficient to induce the spawning of H. nemurus. The egg quality of fish treated with GnRHa at doses 20μg/kg and 50μg/kg were numerically different, however, there was no significant difference (P>0.05). Ovaprim treated fish produced the best results. Ovulatory response ranged from 50.0% to 66.7% among all the treatments with high fertilization rate (94-95%). The highest hatching rate (78.3%) and percentage of normal larvae (68.8%) was observed from ovaprim injected fish. The results indicated that 20μg/kg and 50μg/kg BW GnRHa were effective in inducing ovulation and spawning in H. nemurus and ovaprim can be recommended to be used by hatcheries to induce H. nemurus for spawning. The major significance of this work was 5μg/kg dose of GnRHa is ineffective for ovulation in H. nemurus.

In recent decades aquariculture has emerged as a globally growing million dollar industry comprising cultivation of various freshwater and marine species of finfish as well as shellfish. Pigmentation is one of the major quality attributes of the aquarium fish for market acceptability. Carotenoids are responsible for pigmentation of muscle in food fish and skin color in ornamental fish. Like all other animals fishes are unable of de novo synthesis of carotenoids and rely on diet for fulfillment of carotenoids. Properly formulated feed is the major backbone
of successful culture of ornamental fish in confined environment. In this review paper an attempt has been made to prioritize the importance of carotenoids in aquariculture.

Production potential of shingi, Heteropneustes fossilis and koi, Anabas testudineus in polyculture were assessed at a stocking density of 2, 47,000 and 3, 70,500 ha-1, respectively in treatment T1 and T2. Monoculture of H. fossilis and A. testudineus was designed at a stocking density of 2, 47,000 ha-1 in treatment T3 and T4, respectively. Culture period of shingi was 120 days and koi was 100 days in all treatments. All fingerlings were of the same age at stocking, with a mean weight of 2.54±0.08 g for shingi and 0.50±0.01 g for koi, respectively. Commercial fish feeds (30.0% crude protein) supplied at the rate of 100 to 5% of total biomass twice daily. Fish production in treatment T1, T2, T3 and T4 were 18,803±111, 12,388±115, 10,042±5 kg ha-1 day-120 and 22,176±7 kg ha-1 day-100, respectively. The feed conversion ratio (FCR) was significantly (P<0.05) lower in T4 than that of the other three treatments. The net financial benefits incurred from treatment T1, T2, T3 and T4 were Bangladeshi Taka 17,65,769; 6,691; 15,83,990 and 16,29,409 BDT ha-1, respectively. The mean differences of gross yields and net benefits among different treatments were significant (P<0.05). The polyculture technology of shingi and koi, and monoculture technology of koi may help to meet the dietary needs and improve the socio-economic status of the people of Bangladesh.

Fish traps are passive fishing gear which lured the fish either for food or shelter and get trapped through appropriate hard or soft structures. Documentation of these traditional fish trapping methods from the northeastern parts of India is limited. This study attempts to document the traditional fish trapping devices from four districts of Meghalaya with respect to its structure and operation. The depicted survey highlights 11 types of fish traps which were classified into three major categories such as tubular, basket and box traps. Average length of these documented traps ranged from 0.25-1.5 m and mostly operated during monsoon and post-monsoon season in floodplain and low-lying areas like rice fields, ponds, shallow rivers and ditches. Murrels, minnows, barbs, mahseers and catfishes were the dominant fish catch from these gears. Most of the traps were fabricated with bamboo and locally available materials with a life span of more than 2-3 years. Results revealed that Khnu/Chiap, is the most popular and efficient trap with a CPUE of 2.5 kg day-1 trap-1. Documentation and the knowledge concerning the traditional gears will facilitate to improvise the fishing gears which will ultimately improve the livelihood of fishermen in the northeastern region of India.

The biblical signs to distinguish between kosher and non-kosher fish seem exceedingly straightforward: the presence of fins and scales defines a fish as kosher. Despite this seeming simplicity, there have often been difficulties in classifying certain fish. The swordfish (Xiphias gladius) is an example of a fish with an interesting halakhic history. Possibly mentioned as early as the Tosefta, a " fish with a sword " was permitted in the 17th century and repeatedly thereafter. In the 20th century, the kosher status of the swordfish became the subject of an acrimonious debate between the Orthodox and Conservative rabbinate in the United States, and between American Orthodox rabbis and the Israeli rabbinate. This paper traces that history, presents the arguments of the various players, and endeavors to explain why those who prohibited the swordfish seem to have won.

Memahami osmoregulasi pada embrio dan larva ikan adalah kunci untuk manajemen yang efektif dari populasi alami banyak spesies laut, yang pada awal siklus hidup mereka mungkin terkena cukup variasi salinitas (misalnya di muara sungai atau di sungai di mana spesies anadromus berkembang biak). Pada larva ikan air tawar, osmoregulasi membutuhkan energi yang besar. Mengetahui pengorbanan antara pengeluaran energi pada osmoregulasi dan pengeluaran energi pada asimilasi dapat menyebabkan wawasan penting dalam pengembangan dan pertumbuhan ikan

Laporan yang berisi Pertumbuhan Ikan, Perbedaan Ikan Jantan dan Betina, Studi Isi Alat Pencernaan dan Derajat Kepenuhan Lambung, Pengamatan Gonad, Fekunditas, Telur Ikan di Laboratorium Pemanfaatan Sumberdaya Perikanan Fakultas Perikanan dan Ilmu Kelautan Universitas Jenderal Soedirman

Penelitian perkembangan dan kelangsungan hidup larva kerang mutiara (P.
maxima) pada kondisi suhu yang berbeda telah dilaksanakan di Laboratorium Unit
Pelaksana Teknis Loka Pengembangan Bio Industri Laut Mataram, Pusat
Penelitian Oseanografi Lembaga Ilmu Pengetahuan Indonesia dari 10 Februari -
17 Maret 2016. Penelitian bertujuan untuk mengetahui kisaran suhu optimum bagi
perkembangan dan kelangsungan hidup larva kerang mutiara (P. maxima). Ukuran
larva kerang mutiara (P. maxima) yang digunakan dalam penelitian ini yaitu 80 x
75μm (AP x DV) yang ditentukan berdasarkan fase awal perkembangan larva (Dveliger).
Larva dipelihara dalam bak kontainer dengan kepadatan 20.000 larva
dalam 80 liter air laut pada kondisi suhu yang berbeda. Penelitian didesain
menggunakan rancangan acak lengkap (RAL) dengan lima perlakuan dan tiga
ulangan. Larva kerang mutiara dipelihara pada lima perlakuan suhu yang berbeda,
yaitu 26,5-28oC (perlakuan Kontrol), 26oC±0,5 (perlakuan A), 28oC±0,5
(perlakuan B), 30oC±0,5 (perlakuan C) dan 32oC±0,5 (perlakuan D). Hasil
penelitian menunjukan bahwa tingkat kelangsungan hidup, pertumbuhan mutlak,
laju pertumbuhan spesifik DV dan AP tertinggi didapatkan pada perlakuan B
(suhu 28oC±0,5) dengan nilai masing-masing 8,00%±0,16, 1458,32μm±32,16,
5,46%±0,03 dan 5,71%±0,04. Perkembangan stadia larva kerang mutiara hingga
mencapai spat tertinggi pada perlakuan B (suhu 28±0,5oC) dengan nilai AP x DV
yaitu D-veliger (80 x 75μm), Umbo (170,67μm±30,11 x 153,67μm±26,76),
Eyespot (209,00μm±9,94 x 196,00μm±9,66), Pediveliger (237,22μm±29,86 x
207,50μm±31,17) dan Spat dengan nilai AP (1510,67μm±155,56). Kesimpulan
pada penilitian ini bahwa suhu air optimum pada pemeliharaan larva kerang
mutiara (P. maxima) yaitu 28oC±0.5.

Metabolomics is a fast-evolving field that provides qualitative and quantitative analyses of metabolites within cells, tissues or biofluids. Recent applications of metabolomics approaches in aquaculture research have highlighted the huge potential for solving problems within all aspects of the production line, from hatchery production to post-harvest quality control. To assist with the growing application of metabolomics in aquaculture research, this contribution provides a review of techniques and steps necessary to conduct metabolomics research, from experimental design to data interpretation. Specifically, we target scientists who are new to the field of metabolomics, and we offer simple, but comprehensive steps and strategies to conduct this type of research. We conclude this primer with some advice on how to access relevant expertise and facilities for metabolomics-based aquaculture research.

ABSTRACT

Aquaculture is the fastest growing food production system worldwide and is particularly important in bridging the gap
between fish demand and supply in Nigeria. This study was carried out to determine factors affecting aquaculture fish seed
production and management in Ogun State, Nigeria, an important coastal and fish producing state. Through structured
questionnaire and personal interviews, data were collected from 58 hatcheries and analyzed using descriptive and inferential
statistics. Major challenges identified by this study include lack of good quality brood stock, high mortalities during larval
development, high costs of hatchery inputs and equipment, water quality maintenance and energy-related problems. It is
recommended that government should offer low-interest loans for continuous training of fish hatchery operators, who should
be mandated to train regularly to update their knowledge on new developments in the industry. These steps should result in
enhanced fish seed production for viable and sustainable aquaculture development in Nigeria.



Keywords: Brood Stock; Fish Seed; Production; Sustainable Aquaculture; Ogun State; Nigeria

As with most medical specialties, haematology has seen major changes since this book was first published in 1998.
We now have greater understanding of the molecular biology of many diseases, both malignant and non-malignant. This new
knowledge has helped us to develop more sensitive assays for many conditions, and has been taken into the clinic, with the
engineering of new drugs, such as STI571 used in the treatment of chronic myeloid leukaemia, amongst others.
As with the first edition, the intention has been to encompass all aspects of haematology but with perhaps a greater emphasis on
basic science than previously. Readers will note that the writing team is almost identical to that for the first edition, which provides
continuity of style.
I would like to express my gratitude to all my haematology colleagues for updating their sections and bringing the entire text up
to date. Key reading lists are provided for all topics for those wishing to read about haematology in greater detail. Thanks must also
go to the BMJ and in particular Mary Banks, Senior Commissioning Editor, and Sally Carter, Development Editor, who have been
key players in the development of the second edition.

Now  a  day,  multidrug  resistance  of  pathogenic  microbes  throws  a
challenge to scientists to discover the source of alternative medicine.
This study focuses on the antimicrobial properties of the leaf extracts
of  five  commonly  known  medicinal  plants–Azadirachta  indica,
Alpine  besseya,  Mentha  longifolia,  Manilkara  zapota,  Bryophyllum
pinnatum.  The  methanolic  and  ethanolic  extracts  of  the  leaf  of  the
above mentioned plants were prepared by distillation method. Then
comparative analysis of antimicrobial effects between those extracts
and  available  antibiotics  in  the  market  were  tested in  Escherichia
coli, Salmonella typhi and Pseudomonas sp.  culture. All of the leaf
extracts have shown potent antimicrobial activity  and the extract of
Bryophyllum pinnatum have shown the most potent activity compare
to others.

Aquaculture production is currently challenged to meet the growing demands for seafood protein throughout the world. To achieve this growth in an efficient, safe and sustainable manner, novel tools and applications will need to be incorporated at each step of the production line. A variety of 'omics' (e.g. transcriptomics, pro-teomics, metabolomics) applications have already begun to emerge in aquaculture research with extreme success. A promising new 'omics' approach is metabolomics, which aims to use metabolite profiles to identify biomarkers indicative of physiological responses of living samples (e.g. whole organism, tissues, cells) to environmental or culture conditions. One of the benefits of this approach is that it uses a broad scan of biological conditions to identify often unexpected problem or risk areas upon which to focus management attention. In this contribution, we have selected relevant research examples to showcase the applications of metabolomics in aquaculture in four major areas: hatchery production, nutrition and diet, disease and immunology, and post-harvest quality control. The novelty of this approach is highlighted by the fact that we cite the majority of published papers in this field, and they are all recent (within the last decade) contributions.

This study aimed to investigate the effect of dietary graded levels of three pre-and probiotics on the immunity and haematology of all-males mono-sex Nile tilapia  fish. The experimental period was 16 weeks after 2 weeks adaptation period.  In the pathogenicity test, dietary inclusion of Aqua Superzyme at 0.01% of the diet, Garlen Allicin at 0.01% of the diet, and Diamond V (XPC)  at 0.5% of the diet, generally
reduced the mortality rate (%) and therefore increased the survival rate (%). Yet, the only significant (P<0.05) positive effect was due to Aqua Superzyme at 0.01% of the diet  in general and after 48h whereas the other supplements  did not  significantly (P>0.05) affect the pathogenicity. The comparisons among substances and their levels
clear that the best survival was occurred in the treatment 1:1, i.e the fish group fed Aqua Superzyme (at 0.01% of the diet) diet. The haematological parameters' values increased significantly (P<0.05) by using Aqua Superzyme, particularly at 0.01% of the diet; Garlen Allicin, particularly at 0.01% of the diet; and  Diamond V (Original XPC), particularly  at 0.4% of the diet). Yet, the overall significantly (P<0.05) best value for all tested parameters among additives and their levels was  that contained
Aqua Superzyme at 0.02% of the diet. So, it is recommended to supply Nile tilapia's diet with the prebiotic Aqua Superzyme at 0.01-0.02% of the diet to improve the immunity system of the fish.

والسران Sarpa salpa الدراسة الحالية تمت على الأسنان الفكية والخيشومية لنوعين مختلفين من الأسماك البحرية مختلفة التغذية (الشلبة م، وذلك بواسطة شباك الجرف. نتائج الدراسة 2017  خلال فصل الربيع ، ). جمعت الأسماك من الشاطيء البحري لمدينة مصراتة Serranus scriba الحالية أظهرت أن أسنان الفكوك والقوس الخيشومي الأول تباينت في الشكل والترتيب بين أسماك الدراسة، حيث كانت الأسنان الأمامية منشارية ذات  لها تسنن مضاعف، في حين تميزت أسماك السران بأسنان فكية نابية ذات نهاية علوية مستدقة متجهة للخلف، وتمتد على ، نهاية حادة وجانبية نابية كامل الفك السفلي، بينما تميز الفك السفلي بوجود عدد أقل من الأسنان النابية المنحنية للخلف والعديد من الأسنان الجانبية الصغيرة. أسنان القوس  قصيرة ومستديرة النهاية على الجزء العلوي من القوس الخيشومي الأول، ومتطاولة ومستدقة ، الخيشومي الأول لأسماك الشلبة كانت أصبعية الشكل وكانت أكثر ، وتحمل تسنن مضاعف على طول السطح الخارجي لكل سن ،النهاية على السطح البطني لحول الخيشومي. في حين كانت طويلة ورقيقة طولا على النهاية الحرة لأسماك السران. كان التباين الشكلي في أسنان الفكوك والأقواس الخيشومية تكيفا لنوع الغذاء الذي تقتات عليه أسماك الشلبة والسران.

An on-farm experiment was undertaken in nine earthen ponds to evaluate the growth and production potentials of stinging catfish shing, Heteropneustes fossilis for the period of six months from March to August 2010. Three stocking densities such as 1,25,000 (T1), 1,87,500 (T2) and 2,50,000 ha-1 (T3) were tested with three replications each. Fish were fed with commercial pelleted feed containing 35% crude protein. After six months rearing, the mean harvesting weights of shing were 69.42±6.20, 58.74±3.85 and 49.50±4.52g in T1, T2 and T3, respectively. Significant (P<0.05) highest mean harvesting weight was found in T1. The best survival was found in T1 (87%) among the treatments. The calculated mean production of shing (H. fossilis) in three treatments such as T1, T2 and T3 were 7549±52, 9031±71 and 8786±60 kg ha-1, respectively, which were significantly different (p<0.05) from each other.