Megalaspis Research Articles

A study on some commercial fishes of Nyaw-byin coastal water, Launglone Township, Tanintharyi region, Myanmar

A total of 10 species (nine families of Belonidae, Clupeidae, Chirocentridae, Mugilidae, Carangidae, Drepaneidae, Lutjanidae, Monodactylida and Sciaenidae under 4 orders) of some commercial fishes was collected from Nyaw-byin coastal water, Launglone Township from April 2019 to March 2020. The collected specimens comprised Albennes hians, Tennualosa ilisha, Chirocentrus dorab, Mugil cephalus, Megalaspis cordyla, Scomberoides tala, Drepane punctata, Lutijanus lunulatus, Monodactylus argenteus and Nibea soldado. The distribution and occurrence of some commercial fishes is present in all year round. In addition, habitats of ecah species, local distribution of some commercial fishes are briefly described.

Total Mercury (THg) Concentration in Indian Scad (<i>Decapterus russelli</i>) and Torpedo Scad (<i>Megalaspis cordyla</i>) from Southern Waters of Binuangeun, Banten

The high level of fish consumption was the main factor in the vulnerability of Hg exposure to the human body. The preliminary information of the total mercury (THg) concentration of Indian scad (Decapterus russelli) and Torpedo scad (Megalaspis cordyla) from Binuangeun fish auction in Lebak, Banten, Indonesia, was presented in this research. The objective of this research was to understand the distribution of THg in each organ of D. russelli (muscle, gut tissues, gonad, and eggs) and M. cordyla (muscle, liver, and gut contents). The results showed that THg in all samples were below the National Regulation limit from the National Agency of Drug and Food in mg/kg ww. THg gonad from D. russelli was showed highly significant (P < 0.01) lower compare THg in muscle, gut tissues, and eggs. Pearson’s correlation from THg in each organ of D. russelli compare to total weight and total length showed that concentration of THg in gonad highly significantly (p < 0.01) correlated with total body weight (r2 = 0.97) and total length (r2 = 0.96). M. cordyla was showed no correlation of THg in muscle compare to total length and total weight. The present study showed that D. russelli could accumulate higher mercury compare to M. cordyla and need caution while consuming this fish.

Comparative analysis of chemical composition of some commercially important fishes with an emphasis on various Malaysian diets

AbstractThis study compares the chemical composition of cockle (Anadara granosa) and some commercially important marine (Asian seabass Lates calcarifer, grouper Epinephelus bleekeri, hardtail scad Megalaspis cordyla, longtail tuna Thunnus tonggol and Indian mackerel Rastrelliger kanagurta) and freshwater (sutchi catfish Pangasius hypophthalmus, Nile tilapia Oreochromis niloticus and eel Monopterus albus) fishes in Peninsular Malaysia. The results show that the proximate composition and trace metal content were significantly different (P < 0.05) among species investigated. The mean protein content was the highest in eel (19.1%) and the lowest in sutchi catfish (13.0%) and cockle (13.0%). The mean lipid content of Indian mackerel (3.9%) was higher than cockle (2.0%), followed by eel (1.3%) and longtail tuna (0.8%). The mean ash content was the highest in Indian mackerel (1.4%) and the lowest in cockle (0.9%). Zinc and manganese contents in cockle (Zn: 61.2 mg kg−1, Mn: 22.7 mg kg−1) were very high compared to other species investigated. The copper content was minimum in sutchi catfish (1.0 mg kg−1) and a maximum in the hardtail scad (11.7 mg kg−1). Trace metal content in sutchi catfish, Nile tilapia, grouper, longtail tuna, eel and cockle followed an order Zn > Mn > Cu, whereas Asian seabass, hardtail scad and Indian mackerel followed a different order Zn > Cu > Mn. Trace metal content in the tissue of the fishes examined was within safe limits for human consumption except Mn content in the cockle and Cu content in the hardtail scad, which is a matter of concern. When considering the daily fish fat, mineral and trace metal intake, marine fishes and shellfish are better than freshwater fishes.

Implication of single year seasonal sampling to genetic diversity fluctuation that coordinates with oceanographic dynamics in torpedo scads near Taiwan

Many fisheries management and conservation plans are based on the genetic structure of organisms in pelagic ecosystems; however, these structures tend to vary over time, particularly in cyclic ocean currents. We performed genetic analyses on the populations of the pelagic fish, Megalaspis cordyla (Osteichthyes: Carangidae) in the area surrounding Taiwan during 2000–2001. Genotyping was performed on M. cordyla collected seasonally around Taiwan as well as specimens collected from Singapore (Malacca strait) and Indonesia (Banda Sea). Gonadosomatic indices (GSI) revealed that M. cordyla does not spawn near Taiwan. Data related to the mitochondrial control region revealed that the samples from Singapore and Indonesia represented two distinct genetic cohorts. Genotyping revealed that during the summer (June–August 2000), the Indonesian variant was dominant in eastern Taiwan (presumably following the Kuroshio Current) and in the Penghu region (following the Kuroshio Branch Current). During the same period, the Singapore genotype was dominant along the western coast of Taiwan (presumably following the South China Sea Current); however, the number dropped during the winter (December–February 2001) under the effects of the China Coast Current. Divergence time estimates indicate that the two genetic cohorts split during the last glacial maximum. Despite the fact that these results are based on sampling from a single year, they demonstrate the importance of seasonal sampling in unravelling the genetic diversity in pelagic ecosystems.

Length-weight, maturity, and condition factor of torpedo scads (Megalaspis cordyla Linnaeus, 1758) in the Java Sea, Indonesia

Abstract. Oktaviani D, Priyanto E, Nugroho D. 2020. Length-weight, maturity, and condition factor of torpedo scads (Megalaspis cordyla Linnaeus, 1758) in the Java Sea, Indonesia. Biodiversitas 21: 1527-1534. The Java Sea comprises the most extensive ecosystem with high pressure on the biodiversity of marine fish species in Indonesia. Small pelagic fish is the main target among marine fish species in this area for decades to fulfill the need for animal protein for human consumption. Torpedo scads (Megalaspis cordyla Linnaeus, 1758) locally called as tetengkek is one of the common species caught in small pelagic seiners fisheries in the area. The significant increasing trend of annual fish landing could lead to unsustainable long-term harvesting. This study was performed to support baseline information on the biological characteristics of Torpedo scads. Measurements on length, weight, sex, maturity, and gonad weight are the main database that collected from February to December 2017 in the Tegal fishing port, north coast of central Java. A total of 2139 specimens were available for monthly length-frequency measurements, and 601 specimens among them specifically observed for length-weight, sex, maturity stage, and their gonad weight. The result showed that fish caught within a range of 16.0-35.4 cmFL and weight of 40-570 g. The length-weight relationship tends to be isometric with the equation of L = 7.e-03 W3.1511. The male and female ratio at 1.07: 1.0 with most of the fish caught at an immature stage (77% of males and 63% of females). Average Fulton condition factor (Kn) of 1.15­+0.09 (0.86-1.64). A wide range of GSI indicates that torpedo scads partially spawn at each month of the year.

A Multi-Criteria Approach and Sustainability Index as a Consideration on Torpedo scad Fisheries Management in Sunda Strait

HighlightsThe main problem to ensure the good management in fisheries was multi species fishPrecautionary approach needed to get a good view of the important criteria in fisheries managementNeeded a multi criteria and index to make a final conclusion of the any criteriaNatural history and population dynamic parameter important input to sustainability indexValidation model in sunda strait as preliminary approach will help to get a good data and resultAbstractTorpedo scad species known are both economic and ecologic important pelagic fish that fishing catch tends to increase last a few decades. For sustainability, in the long term, needed a management strategy that complies with measurable fish population indicators. This effort is a part of the precautionary approach in fiseries management in related exploitation. This research was conducted in Labuan fishing port performed for more than 8 months and then analyzed with population parameters. Composite analysis by multi-criteria approaches found that the average score of Torpedo scad is 1.48 and then grouped as moderate sustainability. Schooling fish, including torpedo scad has been moderate until high sustainability levels. Overall population status in this area refer to moderate potential risk and needs a precautionary approach on management.

Analysis of natural formaldehyde formation on several types of marine fish circulating in Jakarta

Formaldehyde is dangerous to health because it is a carcinogen that can cause cancer. Jakarta Province has an integrated food control program, namely fish supervision, free from formaldehyde. The test results during the management there were several fish containing formaldehyde, namely moonfish (Lampris guttatus), hardtail scad (Megalaspis cordyla), rank goby (Saurida tumbill), and mackerel scad (Decapterus spp). There is no information regarding the detected formaldehyde in these fish, so this study aims to analyze the natural formaldehyde formation process of the four types of marine fish to ensure that the detected formaldehyde results from addition or naturally occurring. This study also describes how fishers in Jakarta consider environmental factors in the fish handling process. This study used a completely randomized design and ANOVA in determining levels of formaldehyde. The qualitative approach carried out using interviews and observations. The parameters studied were formaldehyde levels, Total Volatile Base (TVB), and Trimethyl Amin (TMA). The results showed that moonfish, hardtail scad, rank goby, and mackerel scad increased natural formaldehyde content during storage, namely 0 mg/kg on day 0 to 6.51 mg/kg on day 18. The formation of natural formaldehyde in the four types of samples during storage in freezing temperature correlates with the degradation process based on the TVB and TMA parameters. Although the fishermen understand that environmental factors determine natural formaldehyde formation in fish, they are not worried because it does not directly impact consumers’ health. Therefore, it is necessary to increase environmental awareness for anglers to maintain consumer health.

Optimization of Immobilization Conditions for Protease Extracted from Torpedo Scad (Megalaspis cordyla) Viscera Using Response Surface Methodology (RSM)

Protease was extracted from the viscera of torpedo scad fish (Megalspis cordyla) to obtain the crude extract which was then partially purified in 70% ammonium sulphate. The collected precipitate was dialysed and subsequently immobilized in sodium alginate and calcium chloride solution. The optimum concentrations of sodium alginate and calcium chloride to produce the highest yield of immobilized protease was determined by using Response Surface Methodology (RSM). From the results, the optimum conditions obtained were 2.5% of sodium alginate and 0.25 M of calcium chloride achieving a yield of 55.52%. Thus, the utilization of 2.5% sodium alginate and 0.25 M calcium chloride as the immobilization media were able to produce yield of immobilized protease from torpedo scad viscera with the highest proteolytic activity.

Redescription of Rhadinorhynchus trachuri Harada, 1935 (Acanthocephala: Rhadinorhynchidae) from Marine Fish in Vietnam and California with a Discussion of its Zoogeography.

Rhadinorhynchus trachuri Harada, 1935 is probably one of the most widely distributed acanthocephalans in the world, but the least known taxonomically. This report fills the large gap of knowledge about its taxonomy, host relationships, and worldwide distribution in marine fishes of both sides of the Pacific Ocean and the connecting Indian Ocean. To revisit the taxonomy of this species, provide a more complete morphological description and expand our knowledge about its morphological identity and variations and elaborate on its worldwide zoogeography; accounting for its worldwide distribution based on new collections, museum specimens, and on published reports. Specimens from Vietnam were processed, identified, and documented using standard techniques. Specimens of R. trachuri were studied from three species of fish in three families, Auxis thazard (Lacépède) (Scombridae), Megalaspis cordyla (Linn.) (Carangidae), and Tylosurus sp. (Belonidae) in Nha Trang and Binh Thuan in the south Pacific coast of Vietnam and additional museum specimens mostly from salmonids from the Pacific coast of California were also studied. Extensive research was conducted on published records of R. trachuri and its marine fish hosts worldwide. Specimens of R. trachuri are characterized by cylindrical trunk with anterior rings of spines and posterior ventral and lateral spines, a proboscis usually with 12 hook rows each with 19-24 hooks, variable position of testes, and a long uterus, uterine bell attached to the dorsal trunk wall, rounded vagina, and unusually dorsal gonopore. The hosts and geographical distribution of R. trachuri suggest a northern linkage of infections between the Asian and American Pacific populations across the Bering Sea involving salmonid fishes and a southern linkage through the Indian Ocean involving Carangid fishes. Other hosts involved in the cycling and distribution of infections are also discussed with some definitive hosts also serving as paratenic hosts. This is the first complete description about R. trachuri and the first comprehensive accounting of its worldwide distribution in 19 species of marine fish in seven families. Considerable intraspecific variability related to geographical restrictions, intermediate and definitive host specificity and distribution, and host feeding behavior was documented.

IDENTIFIKASI JENIS IKAN (PENAMAAN LOKAL, NASIONAL DAN ILMIAH) HASIL TANGKAPAN UTAMA (HTU) NELAYAN DAN KLASIFIKASI ALAT PENANGKAP IKAN DI PULAU BANGKA PROVINSI KEPULAUAN BANGKA BELITUNG

Identification of fish species has an important meaning when viewed from a scientific angle because the entire sequence of subsequent work depends on the results of the correct identification of a species. The purpose of this research is to analyze the types (local, national, scientific name) and types of fishing equipment operating in the Bangka Island. This research was conducted in October 2018 to April 2019 at the Bangka Island. The method was used purposive sampling. The analysis was carried out by descriptive analysis and PSR (Pressure, State, Response). The result show that there were 30 types of fishing gear that were included in seven classes that are surrounding nets, trawls, seine nets, lift nets, gillnets, traps, hooks and lines. The main fish caught from 30 types of fishing gear used are 73 species which are included in small pelagic fish, large pelagic fish and demersal fish consisting of 38 families. More than 50% of the local names of fish on Bangka Island are different from the names of national fish including Yellow Stalk Fish, in the Bangka area called the Ciu Fish (Selaroides leptolepis), local name Selar Como Fish called Hapau Fish (Atule mate), local name Tetengkek Fish is called Singkur Fish (Megalaspis cordyla), local name Kuwe Onion Trevally Fish is called Sweet Beautiful Fish (Carangoides caeruleopinnatus), Tembang Fish is the local name Tamban Fish (Sardinella gibbosa), Bloso Fish is the local name Buto Cin Fish (Saurida tumbil). Recommendations given are that stakeholders should pay attention to local name so there is no error in data collection and use of enviromentally friendly fishing gear by taking into account the selectivity of fishing gear.

Morphological and molecular description of Rhadinorhynchus laterospinosus Amin, Heckmann & Ha, 2011 (Acanthocephala, Rhadinorhynchidae) from marine fish off the Pacific coast of Vietnam.

Rhadinorhynchus laterospinosus Amin, Heckmann & Ha, 2011 (Rhadinorhynchidae) was described from a single female collected from a trigger fish, Balistes sp. (Balistidae) from the northern Pacific coast of Vietnam in Halong Bay, Gulf of Tonkin. More recent collections of fishes in 2016 and 2017 revealed wider host and geographical distributions. We report this Acanthocephala from nine species of fish representing six families (including the original record from Balistes sp.) along the whole Pacific coast of Vietnam. The fish species are Alectis ciliaris (Carangidae), Auxis rochei (Scombridae), Auxis thazard (Scombridae), Leiognathus equulus (Leiognathidae), Lutjanus bitaeniatus (Lutjanidae), Megalaspis cordyla (Carangidae), Nuchequula flavaxilla (Leiognathidae), and Tylosurus sp. (Belonidae). We provide a complete description of males and females of R. laterospinosus, discuss its hook metal microanalysis using EDAX, and its micropores. Specimens of this species characteristically have lateral trunk spines bridging the anterior ring of spines with posterior field of ventral spines and a proboscis with 15–19 longitudinal alternating rows of 21–26 hooks each varying with host species. We demonstrate the effect of host species on the distribution and size of the trunk, proboscis, proboscis hooks, trunk spines, and reproductive structures. The molecular profile of this acanthocephalan, based on 18S rDNA and cox1 genes, groups with other Rhadinorhynchus species and further seems to confirm the paraphyly of the genus, which is discussed.

Descriptions of Neorhadinorhynchus nudum (Cavisomidae) and Heterosentis paraholospinus N. SP. (Arhythmacanthidae) (Acanthocephala) From Fish Along the Pacific Coast of Vietnam, With Notes On Biogeography.

Two species of acanthocephalans are described from fishes caught along the Pacific coast off eastern Vietnam in 2016: (1) Neorhadinorhynchus nudum ( Harada, 1938 ) Yamaguti, 1939 (Cavisomidae) from the frigate tuna Auxis thazard (Lacépède) (Scombridae) in Nha Trang, Pacific south Vietnam, and (2) Heterosentis paraholospinus n. sp. (Arhythmacanthidae) from 3 species of fish: the common ponyfish Leiognathus equulus (Forsskål) (Leiognathidae) and the torpedo scad Megalaspis cordyla (Linn.) (Carangidae) off Nha Trang and Binh Thuân, respectively, and the yellowspotted ponyfish Nuchequula flavaxilla Kimura, Kimura, and Ikejima (Leiognathidae) at Quang Ninh in Pacific waters of Vietnam. Females of N. nudum are fully described for the first time in the Pacific Ocean. Heterosentis paraholospinus n. sp. is similar to Heterosentis holospinus Amin, Heckmann, and Ha, 2011, in having an unspined anterior trunk cone, nucleated pouch at the posterior end of the receptacle, and spines covering the entire trunk, but it differs in having a long cylindrical trunk, lemnisci much longer than the receptacle, more and different-sized proboscis hooks, and subterminal female gonopore. Biogeographical notes are discussed for both genera.

Empirical acoustic TS - Length relationship for Torpedo Scad (Megalaspis cordyla)

One of the main challenge in fish stock assessment with acoustic method is how to improve the accuracy of the estimated acoustic target strength (TS) of the fish under investigation. Various factors contribute to the bias in acoustic TS, namely the high diversity of fish species, body shape, orientation and size. It is therefore necessary to have a database of acoustics TS of fish on a particular species, size (length), and orientation as a reference to be used in grouping and in estimating the over all TS-length relationship of the species. In this paper we reported the result of in situ TS measurements of Torpedo Scad (Megalaspiscordyla). The TS data analysis is performed numerically through the best-fit technique to establish the relationship between length, object orientation, and TS. The TS-length relationship obtained for Torpedo Scad (Megalaspis cordyla) is TS = 20 log (FL)–53.68.This relationship could be used to eliminate bias in the fish stock assessment by acoustic method.

Analysis of Heavy Metal Accumulation in Fish at Terengganu Coastal Area, Malaysia

Bioaccumulation of toxic metals in fish causes serious threats to human when they are consumed. Thus, the detection of toxic element concentration levels in aquatic component is important. The accumulation of some heavy metals such as Cd, Cu, Fe, Mn, Pb and Zn in fish were determined. Ten species (Selaroides leptolepis, Decapterus maraudsi, Epinephelus lanceolatus, Priacanthus tayenus, Rastrelliger, Megalaspis cordyla, Nibea soldado, Pristipomoides filamentosus, Bramidae and Siganus canaliculatus) were collected from Terengganu coastal area, Malaysia. The analysis was done using inductive coupled plasma-mass spectrometer (ICP-MS) technique. In general, the concentration levels of heavy metals in fish samples are lower than the previous study in various locations. The highest average level of heavy metal recorded in fish is Fe followed by Zn, Mn, Cu, Cd and Pb. The metal concentration found in this study was lower than the national and international recommended dietary allowance (RDA) for human consumption except Fe (52.33 × 10-2 ± 6.39 × 10-2 mg kg-1) which exceeded the limit of 0.3 mg kg-1. Long term monitoring system of metal bioaccumulation in fishes need to be done to provide useful information for the assessment of the potential health risks of metals in Malaysia.

Detection of Grillotia erinaceus (Cestoda: Trypanorhyncha) in Megalaspis cordyla (Linnaeus, 1758) (Perciformes: Carangidae) from the Persian Gulf

Cestode species of the genus Grillotia Guiart, 1927 are among the most commonly encountered trypanorhynch cestodes, either as the adult in elasmobranchs or as the plerocercus (larval stage) in teleost fishes. In this study, we report Grillotia erinaceus (Cestoda: Trypanorhyncha) from a teleost fish, Torpedo scad, Megalaspis cordyla (Linnaeus, 1758), from the Persian Gulf for the first time. The specimens of G. erinaceus were obtained from subcutaneous tissues of Torpedo scad collected from a fish market in Bandar Abbas, Iran. No reaction, inflammation or exudate was seen in examined tissues.

Risk of Dietary Mercury Exposure via Marine Fish Ingestion: Assessment Among Potential Mothers in Malaysia

Mercury (Hg) is a very toxic heavy metal that can permanently damage the brain of a developing fetus, particularly through maternal fish consumption. Being the highest seafood consumers in South East Asia, Malaysian mothers are probably at Hg exposure risk. Hence, this study was undertaken to assess the health risk associated with Hg from marine fish consumption and the types of fish that could possibly increase the exposure dose. Assessment was done among potential mothers (n = 311) in the coastal rural and urban parts of Selangor, the most dense and developed state of Malaysia. Coastal rural women consumed significantly higher amounts of fish than their urban counterparts (164.0 vs. 111.7 g/day, p = 0.03) with Indian mackerel and torpedo scad being the most consumed species. These species also contributed to the highest average daily dose (ADD) of Hg. Consistent with the fish intake rate, coastal rural women were also clearly at higher risk of Hg exposure than their urban counterparts. The fish species that contributed to a significant Hg dose for both respondent groups was Indian mackerel. In addition, torpedo scad, yellow-banded scad, fourfinger threadfin, and golden snapper were the other species that significantly increased the exposure dose among coastal rural women, whereas for urban women, it was Indian scad, Japanese threadfin bream, and pale-edged stingray. Although the HQ calculated based on THg was lower than the unity HQ = 1.0, the identified species should be consumed with caution, especially by sensitive population groups.

DNA barcoding technology to identity spawn from the Jiangmen marine environment in summer

PDF HTML阅读 XML下载 导出引用 引用提醒 基于DNA条形码技术对江门沿岸海域夏季鱼卵的鉴定 DOI: 作者: 作者单位: 1. 中国水产科学研究院南海水产研究所, 农业农村部南海渔业资源开发利用重点实验室, 广东 广州 510300;2. 上海海洋大学 水产与生命学院, 上海 201306 作者简介: 张楠(1987-),男,助理研究员,从事水产种质资源研究.E-mail:zhangnhs@163.com 通讯作者: 中图分类号: S917 基金项目: 科技部科技基础性工作专项（2013FY110700）；中国水产科学研究院中央级公益性科研院所基本科研业务费专项（2013A11）；农业部重大财政专项（NFZX2013）；国家科技基础条件平台建设运行项目（2017DKA30470）. DNA barcoding technology to identity spawn from the Jiangmen marine environment in summer Author: Affiliation: 1. Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs;South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China;2. College of Aqua-life Science and Technology, Shanghai Ocean University, Shanghai 201306, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以江门沿岸海域夏季采集到的鱼卵研究对象，利用DNA条形码技术分析鉴定鱼卵种类。本研究获得鱼卵个体有效线粒体COI序列信息217个，测序成功率为68.5%。经BOLD数据库比对分析，成功鉴定鱼卵5目14科19属20种（未知种2种）；种内遗传距离为0~0.006，平均遗传距离为0.002，种间遗传距离为0.149~0.325，平均遗传距离为0.255，种间遗传距离为种内遗传的128倍；鱼卵样品以鲈形目数量最多，占51.8%；鲱形目次之，占24.8%；其中鱼卵优势种为黄斑鲾（Megalaspis cordyla）、粗鳞鮻（Harpadon nehereus）、亚洲鱚（）。本次调查川山群岛东部海域获得鱼卵数量、鱼卵种类数均最多，是江门沿岸海域日本鳀、龙头鱼的主要产卵场；黄茅海、镇海湾西部水域均未获得鱼卵，可能与水域环境变化及陆源污染导致产卵环境破坏、亲体量减少有关。该研究结果揭示了江门沿岸海域夏季鱼卵分布格局，为其制定有效的产卵场保护措施提供依据，同时表明DNA条形码技术能有效地对鱼卵进行种类鉴定，可被广泛地应用于我国沿海海域鱼卵鉴定工作。 Abstract:The main purpose of this study was to analyze and identify the species of fish eggs from the Jiangmen marine environment in summer, based on DNA barcoding technology. In the present study, we acquired a total of 217 effective mitochondrial COI sequences from fish eggs, and the success rate of sequencing was up to 68.5%. After the alignment of the BOLD database, we found that besides 2 species, a total of 5 orders, 14 families, 19 genera, and 20 species were identified. Statistical analyses showed that the interspecific genetic distances were 0~0.006, and mean interspecific genetic distance was 0.002, whereas the intraspecific genetic distances were 0.149~0.325, and mean intraspecific genetic distance was 0.255, which was 128-fold higher than the former. Among the fish eggs, the most abundant order was Perciformes (51.8%), followed by Clupeiformes (24.8%); the most abundant species was Megalaspis cordyla, , and . In this investigation, the most abundant fish eggs were found in eastern Chuanshan Archipelago, both in numbers and species. The Chuanshan Archipelago is also known as the main spawning site of . However, nearly no fish eggs were found in the Huangmao Bay area or western Zhenhai Bay, possibly owing to environmental disruption and a decrease of effective parent number, triggered by environmental variation and contamination from land-sourced pollutants. In general, we revealed the distribution pattern of fish eggs from the Jiangmen marine environment in summer, which provided a theoretical basis for developing effective protective measures for spawning sites. Meanwhile, the results also showed that DNA barcoding technology could be effective and broadly applied to identify the species of fish eggs in the marine habitats of our country. 参考文献 相似文献 引证文献

Assessment of Maturity, Reproduction and Reproductive Potentials of Torpedo Scad, Megalaspis cordyla (Linnaeus, 1758) from Northern Arabian Sea Coast of Pakistan

Port landing specimens of torpedo scad, Megalaspis cordyla were collected at monthly intervals from August 2013 to June 2014 from the northern Arabian Sea coast of Pakistan. The life history characteristics revealed that torpedo scad has a prolonged breeding season which occurred with two peaks: from May to June and from November to February. The spawning seasonality was also validated with microscopic gonad examination.The highest GSI value was noted in May and January whereas the lowest in November was recorded for both sexes. The age at which individuals of both sexes become 50% mature (t50) was estimated as 2.44 year. Life span (tmax) calculated as 3.96 years for male and females. The size of 270 and 265 mm at which 50% individuals attained sexual maturity (L50) was determined for males and females respectively. The reproductive potential (fecundity)was made from ten ripe females ranged from 29–43.8 cm TL and weighing 220–540 g of IV–V developmental stage was enumerated as 32306–236677 eggs (CV = 2.135) with an average number of eggs 86544 counted per ripe female/season. This study contains fundamental data of an important fish species in the northern Arabian Sea coast of Pakistan. It provides vital information to the fisheries managers for implementation on sustainable use of the resource during spawning season.

Food and feeding habits of the narrow barred Spanish mackerel, Scomberomorus commerson (Lacepede, 1800) off Karnataka, south-west coast of India

Scomberomorus commerson were collected on weekly basis during January 2012 to December 2014 at Mangalore Fishing Harbour. Stomach of 214 narrow barred Spanish mackerel measuring from 48 to 105 cm fork length (FL) for males and 45.5 to 115 cm FL for females were analysed to study their feeding habits. Fish with empty stomach were prevalent in almost all the months. Prey mainly comprised of fishes and crustaceans, with the fish component forming 99.9%. The index of relative importance (IRI) showed that the dominant prey were semi-digested fish remains (44.6%) of Sardinella longiceps (30.1%), Decapterus sp. (18.7%), whitebaits (2.5%), Rastrelliger kanagurta (1.5%) and Epinephelus spp. (1.1%), while Saurida sp. (0.7%), Megalaspis cordyla (0.5%), Scombroides sp. (0.2%) and shrimps (0.1%) were found occasionally in the gut. Index of stomach fullness (SFI) was 0.11 in August and 0.65 in January. Generally, SFI was higher during September to January and lower during February to August. The empty stomach ratio (ESR) ranged from 33.3% (August) to 92.3% (April).

Assessing Target Strength, Abundance, and Biomass for Three Commercial Pelagic Fish Species along the East Coast of Peninsular Malaysia Using a Split-Beam Echo Sounder

ABSTRACT Hashim, M.; Aziz, M.F.H.A.; Hassan, R.B., and Hossain, M.S., 2017. Assessing target strength, abundance, and biomass for three commercial pelagic fish species along the east coast of Peninsular Malaysia using a split-beam echo sounder. Decapterus maruadsi (round scad), Megalaspis cordyla (torpedo scad), and Selar boops (oxeye scad) are commercially important small pelagic fish species of Malaysia. Despite their commercial and ecological value, little is known about their target strength (TS), spatial and vertical distributions, and biomass estimates. A split-beam acoustic survey was performed in the east coast of Peninsular Malaysia (ECPM) in March–June 2009. The calibrated echo sounder allowed determination of TS, estimation of fish density (spatial distribution) and biomass, and produced density maps along depth gradients (vertical distribution). The TS–length relationships indicated that the logarithmic TS was proportional to the squared length. Additional water parameters that included salini...