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Pesquería de Crustáceos Demersales
No full textEn Chile la pesquería de crustáceos demersales se sustenta en la explotación de camarón nailon (Heterocarpus reedi), langostino amarillo (Cervimunida johni) y langostino colorado (Pleuroncodes monodon). Estos recursos poseen una relevancia económica y social para el país, ya que dan origen a una importante actividad industrial y artesanal que genera numerosos empleos directos y aporta divisas por concepto de exportación de productos, principalmente en el rubro de congelados. Este boletín presenta los resultados resumidos del monitoreo de la pesquería de crustáceos demersales explotados entre las regiones de Antofagasta y Biobío.Programa de seguimiento de las principales pesquerías nacionalesPublishedNon Referee
Возрастная структура и линейный рост анадары (Anadara kagoshimensis (Tokunaga, 1906)) Керченского пролива
No full textAge composition and linear growth rate in the ark clam (Anadara kagoshimensis) population in the Kerch Strait are investigated. Based on the analysis of seasonal annual growth rings and chevron grooves on the hinge ligament of the ark clam, the age of this species has been examined, which, in this population, was found to be 7 years (6+). Based on the age and annual length gain of the molluscs in the course of their ontogenesis, a theoretical growth curve is presented; it has been calculated following the von Bertalanffy growth equation, where L∞, k, and t are the parameters equaling to 50.2, 0.428, and 0.022, respectively. The highest growth rate was observed in the first year of life, 17 mm; however, later on, it was consistently decreasing and did not exceed 2 mm/year in the oldest individuals. The relationship between the ark clam’s growth rate (PL) and its length, approximated by the inverse linear function is presented. Based on the parameters of the von Bertalanffy growth equation, a theoretical maximum age of the investigated species has been calculated; it was found to be 8.74 years. It has been shown that the linear growth rate of the ark clam in various areas of the Azov and Black Sea Basin is determined by the water salinity to a considerable extent, because in the desalinated areas (Azov Sea, Kerch Strait, Danube River Delta and Northwestern Black Sea with 10–14 ‰ salinity), the growth rate of this mollusc was 1.5–2 times lower than in the Southeastern Black Sea (18 ‰).Исследована возрастная структура и скорость линейного роста популяции анадары (Anadara kagoshimensis) в Керченском проливе. На основе анализа сезонных годовых слоев роста и шевронных борозд на лигаментной площадке анадары изучен возраст этого вида, который в популяции составляет 7 лет (6+). На основе возраста и годового прироста моллюсков в течение онтогенеза представлена теоретическая кривая роста, рассчитанная по уравнению Берталанфи, где L∞, k, t — параметры, равные 50,2, 0,428 и 0,022, соответственно. Максимальная скорость роста наблюдалась в первый год жизни — 17 мм, однако в дальнейшем она устойчиво снижалась и у наиболее старых особей не превышала 2 мм/год. Показана связь скорости роста (PL) с длиной анадары, которая аппроксимируется обратной линейной функцией. На основе параметров уравнения Берталанфи рассчитан теоретически максимальный возраст исследуемого вида, который составил 8,74 года. Показано, что скорость линейного роста анадары в различных акваториях Азово-Черноморского бассейна в значительной степени определяется соленостью вод, поскольку в опресненных районах (Азовское море, Керченский пролив, дельта Дуная, северо-западная часть Черного моря с соленостью 10–14 ‰) темп роста моллюска был в 1,5–2 раза ниже, чем в юго-восточной части Черного моря (18 ‰).PublishedReferee
Extreme drought event promotes nestedness and reduces temporal beta diversity of benthic invertebrate community in shallow lakes.
No full textExtreme hydrological events, such as droughts, are becoming increasingly frequent and lasting, altering the structure and functioning of aquatic ecosystems. Extreme drought may be able to eliminate species that are not able to persist in this condition. In this context, it was investigated whether prolonged extreme droughts can cause the nestedness pattern and affect the temporal beta diversity of the benthic invertebrate community in areas that commonly undergo flooding processes, such as the lagoons of the upper Paraná River floodplain. For this, samples of benthic invertebrates were used in shallow lakes of the floodplain, in a period in which there was a record of a prolonged extreme drought. A high degree of nestedness of the benthic invertebrate community was observed in most of the sampled environments. It was also found that the lower the depth of the pond, the greater the degree of nestedness of the community. And that this degree of nestedness increases with the duration of prolonged extreme drought. Concomitantly, it was found that the temporal beta diversity reduced over the sampled period, that is, the species composition became increasingly similar as the extreme drought progresses. During the entire period of prolonged extreme drought, the predominant component for the change in composition in the environments was the loss of species. Although there was a change in the composition of the community, it was not significantly affected by the reduction in the depth of the environments, only by the duration of the prolonged extreme drought. In general, extreme drought events can cause negative impacts on the community, resulting in the selective extinction of species and the homogenization of the benthic invertebrate community. As these extreme events are predicted to increase in duration and frequency in the coming years, the impacts on these invertebrates could be even more intense and result in a major loss of biodiversity in these aquatic ecosystems.Eventos hidrológicos extremos, como secas, estão se tornando cada vez mais frequentes e duradouros alterando a estrutura e funcionamento dos ecossistemas aquáticos. A seca extrema pode ser capaz de eliminar espécies que não são capazes de persistirem a esta condição. Nesse contexto, investigou-se se as secas extremas prolongadas podem causar o padrão de aninhamento e afetar a diversidade beta temporal da comunidade de invertebrados bentônicos em áreas que comumente passam por processos de inundação, como as lagoas da planície de inundação do alto rio Paraná. Para isso, utilizou-se amostragens de invertebrados bentônicos em lagos rasos da planície de inundação, em um período no qual houve o registro de uma seca extrema prolongada. Observou-se um alto grau de aninhamento da comunidade de invertebrados bentônicos na maioria dos ambientes amostrados. Verificou-se também que, quanto menor a profundidade da lagoa maior o grau de aninhamento da comunidade. E que este grau de aninhamento aumenta com o tempo de duração da seca extrema prolongada. Concomitantemente, verificou-se que a diversidade beta temporal reduziu ao longo do período amostrado, ou seja, a composição de espécies se tornou cada vez mais semelhante, à medida que a seca extrema progride. Durante todo o período de seca extrema prolongada o componente predominante para a mudança da composição nos ambientes foi a perda de espécies. Apesar de haver mudança na composição da comunidade, esta não foi afetada significativamente pela redução da profundidade dos ambientes, apenas pelo tempo de duração da seca extrema prolongada. De maneira geral, os eventos extremos de seca podem causar impactos negativos sobre a comunidade, resultando na extinção seletiva de espécies e na homogeneização da comunidade de invertebrados bentônicos. Como a previsão é de que esses eventos extremos aumentem em duração e frequência nos próximos anos, os impactos sobre estes invertebrados podem ser ainda mais intensos e resultar em uma grande perda da biodiversidade desses ecossistemas aquáticos.Master
Production of mutton snapper (Lutjanus analis) fry using traditional technology and mesocosm. Use of copepods in early feeding.
No full textCon el objetivo de evaluar el efecto sobre la supervivencia larval y la obtención de alevines del pargo criollo (Lutjanus analis) en la filial del CIP en Santa Cruz del Sur, Camagüey, se emplearon dos sistemas de cría; cultivo tradicional y con la tecnología de mesocosmos. En el primer sistema se usaron cinco tanques de policarbonato de 0,5 m3 de capacidad en condiciones de ambiente controlado con densidad de siembra inicial de 30 larvas/L. En el cultivo en mesocosmos se utilizó un tanque de concreto de 60 m3 de capacidad en áreas exteriores de la filial con densidad de siembra inicial de 3 larvas/L. En el esquema de alimentación larval tradicional se emplearon rotíferos Brachionus rotundiformes “SS” durante las primeras 17 h y Brachionus plicatilis “L” posteriormente, ambos enriquecidos con el producto comercial ALGAMAC 3000 y alimentados con la microalga Nannochloropsis oculata, mientras que el sistema de mesocosmos se inició con la fertilización inorgánica, el uso de rotíferos Brachionus rotundiformes enriquecidos con ALGAMAC 3000 y copépodos (Acartia sp.) para continuar con el uso de alimento particulado y nauplios de Artemia enriquecida según desarrollo ontogenético. El sistema tradicional de cultivo fue suspendido a los 18 días por ausencia de larvas en los tanques de cría, mientras que en el cultivo en mesocosmos, se alcanzaron sobrevivencias larvales de 40,5 % y rendimientos de 1,2 larvas/L. La sobrevivencia de juveniles al final de la experiencia (60 días después de la eclosión) estuvo en el orden del 17,2 %. La cosecha y biomasa final fue de 0,52 juveniles/L y 0,78 kg/m3 respectivamente.In order to evaluate the effect on larval survival to obtaining button snapper (Lutjanus analis) fingerlings in the marine fish culture of Santa Cruz del Sur, Camagüey, two farming systems were used; traditional and Mesocosms systems. Stock density of 30 larvae/controlled environment were set up in five polycarbonate tanks of 0,5 m3 capacity in the traditional system meanwhile 3 larvae/L initial stocking density were stoked in a outdoor concrete tank of 60 m3 capacity to breeding in mesocosms system. Rotifers Brachionus rotundiformes “SS” and Brachionus plicatilis both enriched with commercial product ALGAMAC 3000 and fed with Nannochloropsis oculata microalgae in the traditional feeding larvae scheme were used. Inorganic fertilization, rotifers Brachionus rotundiformes and Artemia nauplii enriched with ALGAMAC 3000 and copepods (Acartia sp.) and particulate feed according to ontogenetic development in the Mesocosms feeding larvae scheme were used. Traditional farming system was suspended after 18 days due larvae absence in breeding tanks. In Mesocosms rearing, larval survival of 40,5 % and yields of 1,2 larvae/L were reached. At the end of the experiment (60 days after hatching), juveniles survival was of 17,2 %. Final harvest showed biomass of 0,52 juveniles/L and 0,78 kg/m3.PublishedReferee
Description of the first to fourth zoeal stages of Macrobrachium equidens (Dana, 1852) (Crustacea: Decapoda: Palaemonidae).
No full textAn ovigerous female of Macrobrachium equidens (Dana, 1852) collected from near shore of Sandspit back waters (Karachi, Pakistan) (Long. 66° 54’ 24”E Lat. 24° 50’ 24”N) on 19, October, 2009, and kept under the laboratory conditions. Larvae were hatched out after 13 days. Zoea I to zoea III stages passed within 6 days at room temperature 31°C, water temperature 29°C, in filtered seawater of a salinity of 37 ‰ and pH 7.9. The Zoea IV of the same species was collected from planktonic sample of Manora Channel, Karachi (Long. 66° 59’ E Lat. 24° 48’ N) on 1995. The larvae of this species are described and illustrated along with comparisons to those described previously.PublishedReferee
Substitution of Fish Meal by Local Vegetable Raw Materials in the Feed of Juvenile Nile Tilapia (Oreochromis Niloticus, Linne, 1758) in Senegal
No full textThe study is a contribution to the development of a feed for juvenile tilapia Oreochromis niloticus, from local raw materials in order to reduce the cost of feeding farmed tilapia in Senegal. Three feeds were formulated from local raw materials. The basic composition of the tested feeds is as follows: A1 (peanut meal, rice bran, millet bran, maize meal and no fish meal); A2 (peanut meal, rice bran, millet bran, maize meal and 10% fish meal) and A3 (peanut meal, rice bran, millet bran, maize meal and 25% fish meal). All feeds contain 31% protein. The trial compared three batches, in 2 replicates, with different diets. The initial weight of the juveniles was 0.37± 0.5g. The daily ration was distributed at 9 am and 4 pm. After 90 days of experiment, the final mean weights were 2.45 ± 0.5g; 2.75±0.5g; and 4.67 ± 0.5g for A1, A2, and A3, respectively. A performance test, of which the objective was to compare growth parameters, was conducted. The results of the growth parameters of juveniles fed A3 were significantly higher (p 0.05) between the two tanks for the same feed treatment.PublishedReferee
An indicator of sea ice variability for the Antarctic marginal ice zone.
No full textRemote-sensing records over the last 40 years have revealed large year-to-year global and regional variability in Antarctic sea ice extent. Sea ice area and extent are useful climatic indicators of large-scale variability, but they do not allow the quantification of regions of distinct variability in sea ice concentration (SIC). This is particularly relevant in the marginal ice zone (MIZ), which is a transitional region between the open ocean and pack ice, where the exchanges between ocean, sea ice and atmosphere are more intense. The MIZ is circumpolar and broader in the Antarctic than in the Arctic. Its extent is inferred from satellite-derived SIC using the 15 %–80% range, assumed to be indicative of open drift or partly closed sea ice conditions typical of the ice edge. This proxy has been proven effective in the Arctic, but it is deemed less reliable in the Southern Ocean, where sea ice type is unrelated to the concentration value, since wave penetration and free-drift conditions have been reported with 100% cover. The aim of this paper is to propose an alternative indicator for detecting MIZ conditions in Antarctic sea ice, which can be used to quantify variability at the climatological scale on the ice-covered Southern Ocean over the seasons, as well as to derive maps of probability of encountering a certain degree of variability in the expected monthly SIC value. The proposed indicator is based on statistical properties of the SIC; it has been tested on the available climate data records to derive maps of the MIZ distribution over the year and compared with the threshold-based MIZ definition. The results present a revised view of the circumpolar MIZ variability and seasonal cycle, with a rapid increase in the extent and saturation in winter, as opposed to the steady increase from summer to spring reported in the literature. It also reconciles the discordant MIZ extent estimates using the SIC threshold from different algorithms. This indicator complements the use of the MIZ extent and fraction, allowing the derivation of the climatological probability of exceeding a certain threshold of SIC variability, which can be used for planning observational networks and navigation routes, as well as for detecting changes in the variability when using climatological baselines for different periods.Challenges 4, 9PublishedReferee
Seguimiento pesquería pelágica zona norte y centro norte
No full textLa actividad extractiva en la zona norte es desarrollada por la flota industrial y artesanal que abastecen a dos empresas pesqueras, una con plantas en los puertos de Arica, Iquique y Mejillones y la otra solo con planta en Iquique. La actividad registra en esta última década los desembarques promedio más bajos (625 mil t).Programa de Seguimiento de las Principales Pesquerías Pelágicas de la zona norte de ChilePublishedReferee
Таксоцен Gastropoda мелководья на рыхлых грунтах в некоторых районах у побережья Крыма (Черное море)
No full textThis paper summarizes our own data on the spatial and temporal distribution of species composition, abundance, biomass and trophic structure of gastropod mollusсs in the shallow-water (0–9 m, mostly up to 5 m in depth) areas along the Black Sea Crimean coast from Karkinit Bay in the northern part of the Crimean Peninsula to Laspi Bay in its South Coast. Over the period spanning from 2001 to 2020, 441 benthic samples were taken at 7 sites in sandy silt biotopes. A total of 31 species was recorded with a maximum (22 species) in Kruglaya (Round) Bay. However, only one species, Bittium reticulatum, was found in all of the investigated areas. The highest abundance (4,243±253 ind./m2) was recorded in the area covering the estuary of Chernaya (Black) River and the head of Sevastopol Bay, and the highest biomass (5.3±0.2 g/m2) was observed in Kazachya (Cossacks) Bay. By these parameters, Hydrobia acuta prevailed. The maximum abundance and biomass of gastropod molluscs in the investigated areas were characteristic of the spring and summer seasons, when the reproduction of the majority of species occurs. The trophic structure of Gastropoda taxocene was very diverse and represented by the following groups: detritivores, scavengers, polyphages, phytophages, predators, ectoparasites, and others (species with unknown type of feeding). In terms of the number of species, phytophages dominated (11 species); detritophages (1,045 ind./m2) dominated in terms of abundance, and scavengers (1.13 g/m2) were dominant by biomass.В работе обобщены собственные данные по пространственно-временному распределению видового состава, численности, биомассы и трофической принадлежности брюхоногих моллюсков в мелководной части (0–9 м, в основном до 5 м) акватории Черного моря вдоль побережья п-ва Крым от Каркинитского залива на севере полуострова до бух. Ласпи на Южном берегу Крыма. Всего за период с 2001 по 2020 г. в 7 районах песчано-илистых биотопов была отобрана 441 бентосная проба. В них встречен 31 вид Gastropoda с максимумом (22 вида) в бух. Круглая. Однако только один вид, Bittium reticulatum, обнаружен во всех изучаемых районах. Наибольшая численность (4243±253 экз./м2) отмечена в районе устья р. Черная – вершины Севастопольской бухты, максимальная биомасса составляла 5,3±0,2 г/м2 в бух. Казачья. По этим показателям преобладала Hydrobia acuta. Пик численности и биомассы брюхоногих моллюсков в исследованных акваториях приурочен к весенне-летнему сезону, когда размножается большинство видов. Трофическая структура таксоцена Gastropoda весьма разнообразна и представлена такими группами, как детритофаги, падальщики, полифаги, фитофаги, хищники, эктопаразиты и прочие (виды с неизвестным типом питания). По количеству видов доминируют фитофаги (11 видов), по численности — детритофаги (1045 экз./м2), а по биомассе — падальщики (1,13 г/м2).PublishedReferee
Экзотические виды рыб у Черноморского побережья Краснодарского края
No full textEach species strives to expand its range and spreads in all directions. Its expansion occurs in the direction where biological and abiotic factors are similar to its native habitat. Entering the area with different conditions activates the mechanism of adaptation to new conditions. If such an adaptation is successful, the range of this species expands in this direction, otherwise this area remains unclaimed. Possible migration routes of exotic species run along the coast of Turkey through the coast of the Republic of Georgia or along the coasts of Bulgaria, Romania and the Crimean Peninsula. Taking into account the existing system of currents in the sea, the most likely option seems to be their invasion into the Russian sector of the Black Sea as a result of migration from the Sea of Marmara through the Bosphorus Strait and further along the direction of the Anatolian and Caucasian currents. Another way is with ballast water. In 1995–2014, 7 monitoring stations under the authority of AzNIIRKH operated near the Black Sea coast of the Krasnodar Territory on a year-round basis. They were equipped with all the necessary types of fishing gear (set nets with a mesh size from 25 to 200 mm, bottom set nets with a minimum mesh size of 6.5 and 10 mm, cast nets with 30 mm mesh, etc.). AzNIIRKH-trained observers were present at each haul of the fishing gear and conducted the necessary catch analyses. All unusual species were preserved by freezing or taxidermy and transferred to the institute. As a result of the operation of AzNIIRKH monitoring stations, in the catches of commercial fishing gear off the Black Sea coast of the Krasnodar Territory in 2005 and 2012, two exotic species have been recorded: Siganus luridus (Rüppell, 1828) and Lophius piscatorius Linnaeus, 1758.Каждый вид стремится расширить зону своего обитания и распространяется во все стороны. Расширение его происходит в том направлении, где биологические и абиотические факторы сходны с его нативным ареалом. При проникновении в акваторию с отличными условиями включается механизм адаптации к новым условиям. Если виду удается приспособиться к этим условиям, ареал расширяется и в этом направлении; в противном случае данная акватория видом не осваивается. Возможные пути миграции экзотических видов пролегают вдоль берегов Турции через побережье Республики Грузия или вдоль побережий Болгарии, Румынии и полуострова Крым. Учитывая существующую в море систему течений, наиболее вероятной представляется версия проникновения их в российский сектор Черного моря в результате миграции из Мраморного моря через пролив Босфор и далее — по направлению Анатолийского и Кавказского течений. Еще один путь — с балластными водами судов. В период 1995–2014 гг. круглогодично у черноморского побережья Краснодарского края работало 7 контрольно-наблюдательных пунктов (КНП) АзНИИРХ. Оснащены они были всеми необходимыми видами орудий лова (ставные сети с размером ячеи от 25 до 200 мм, донные ставные невода с минимальным размером ячеи 6,5 и 10 мм, закидные невода с ячеей 30 мм и др.). Прошедшие подготовку в АзНИИРХ наблюдатели присутствовали при каждой выборке орудий лова и проводили необходимые анализы уловов. Все необычные виды ими фиксировались путем заморозки или изготовления чучел и передавались в институт. В результате работ КНП АзНИИРХ в уловах промысловых орудий лова у черноморского побережья Краснодарского края в 2005 и 2012 гг. были отмечены два экзотических вида: Siganus luridus (Rüppell, 1828) и Lophius piscatorius Linnaeus, 1758.PublishedReferee