Diversity Of Crustaceans Research Articles

The crustacean bycatch of seabob shrimp Xiphopenaeus kroyeri (Heller, 1862) fisheries in the Cananéia region, southern coast of São Paulo, Brazil

The bycatch of shrimp fisheries is highly diverse, but still understudied in the coast of Cananéia (São Paulo, Brazil), where shrimp fisheries are very intensive. Aiming to fill this gap, we analysed the diversity of crustaceans in the bycatch of seabob shrimp (Xiphopenaeus kroyeri) fisheries. Samplings were taken monthly, from March 2013 to May 2014, using a shrimp bottom trawling net aboard a commercial vessel. The crustacean bycatch encompassed 22 families, 36 genera and 46 species. The families with the highest species richness were Portunidae (8 species) and Penaeidae (5 species), corresponding to 17.4% and 10.9%, respectively, of all species caught. Overall, the abundance of X. kroyeri was higher than that of the crustacean bycatch except during in December 2013-February 2014, when the ratio was nearly 1:1 (Binomial test, p <0.05). There was a great variation in the abundance of crustaceans throughout the year, and the highest proportion of bycatch occurred outside the period when the fishery is forbidden. We provide evidence that the trawling in Cananéia captures a great diversity of crustaceans that coexist with the target shrimp species.

Comparing the diversity of interstitial crustaceans at natural and artificial/degraded beaches in Okinawa

Okinawa, a subtropical island in southern Japan, is well-known for its unique biodiversity, but relatively few studies have been conducted to monitor the effects of anthropogenic disturbances on marine ecosystems. Recent work has shown that disturbed artificial beaches have lower numbers and diversity of interstitial amphipods and isopods when compared to natural beaches. In this study, we collected interstitial crustaceans from six different sandy beaches around Okinawa-jima Island in May 2018, including heavily disturbed beaches near reclaimed land, artificial tourist beaches (=disturbed environment), and undisturbed, natural beaches far away from anthropogenic disturbances (=control) in order to more fully explore the range of diversity across a full spectrum of environments. We additionally utilized 18S ribosomal DNA barcodes and Automatic Barcode Gap Discovery (ABGD) to identify specimens to operational taxonomic units (OTUs). DNA barcodes showed 34 OTUs, and the method was more efficiently able to identify to the species-level, while morphological identifications often were only efficient to the genus or family level. In comparison with former data from 2015 in Okinawa, the overall numbers and diversity of amphipods and isopods were lower. Similar to previous results, natural beaches showed higher diversity in comparison with artificial/disturbed beaches. These results suggest that disturbances cause reductions in interstitial crustacean diversity.

Latitudinal species diversity and density of cryptic crustacean (Brachyura and Anomura) in micro-habitat Autonomous Reef Monitoring Structures across Kepulauan Seribu, Indonesia

Abstract. Hazeri G, Rahayu DL, Subhan B, Sembiring A, Anggoro AW, Ghozali AT, Madduppa HH. 2019. Latitudinal species diversity and density of cryptic crustacean (Brachyura and Anomura) in micro-habitat Autonomous Reef Monitoring Structures across Kepulauan Seribu, Indonesia. Biodiversitas 20: 1466-1474. Kepulauan Seribu is located in the north of Jakarta and has historically been affected by anthropogenic activities. Based on its anthropogenic pressure, the archipelago is divided latitudinally into three main parts; the southern part, is a collection of islands located closest to Jakarta Bay and characterized by poor water quality, large sediment and pollutant inputs from nearby rivers, the central and north part that possesses a better water quality. Brachyura and Anomura are dominant crustacean groups in the ocean, which inhabited areas from littoral zone to the deep sea. However, its diversity and abundance are relatively understudied especially in the area where anthropogenic pressure is severe like Kepulauan Seribu. The ARMS (Autonomous Reef Monitoring Structure) is a standardized monitoring method systematically designed for observing indications of organism’s biodiversity in units of time. This research was conducted by employing ARMS as a standardize monitoring procedure to catalog and provide census of Crustaceans (Brachyuran and Anomuran) distributed across the archipelago. All crustacean inhabiting each unit of ARMS were collected and identified. Species diversity was then evaluated to see whether gradient in anthropogenic pressure has a direct impact on species composition and abundance. A total of 24 ARMS units were deployed from 2013 to 2016, located in three zones: south (9), central (9) and north (6) of Kepulauan Seribu. This study identified 17 species from 8 different families of Brachyura and 11 Anomura species from 4 different families from all sites. However, low available identification references for Indonesian crustacean made some specimen were identified only up to family level. The highest species diversity of Brachyura was recorded from family Xanthidae, followed by Portunidae and Pilumnidae, while in Anomura was in Porcellanidae, followed by Paguridae, Galatheidae, and Diogenidae. The high species diversity and density of brachyurans and anomurans were recorded in the central zone. This research infers that the species diversity of Crustaceans (Brachyura dan Anomura) seems dependent on the environmental quality, but most likely all crustacean species depend on the availability of habitat structure.

WITHDRAWN: Comparing the diversity of interstitial crustaceans at natural and artificial/degraded beaches in Okinawa

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Консорты брюхоногого моллюска Rapana venosa (Valenciennes, 1846) в северной части Чёрного моря. Часть IV: Arthropoda

Статья посвящена изучению таксоцена Arthropoda и является продолжением цикла по описанию состава консорции брюхоногого моллюска — вселенца Rapana venosa (Valenciennes, 1846). Консорция R. venosa остаётся неучтённой компонентой в структуре биоценозов шельфа Чёрного моря. Использованный материал и методы исследования детально рассмотрены в предыдущих работах цикла. Цель данной статьи ― описание комплекса эпибионтных организмов и составление аннотированного списка таксонов Arthropoda консорции R. venosa. Найденные в консорции рапаны 27 видов типа Arthropoda относятся к двум подтипам ― Chelicerata (класс Arachnida) и Crustacea (классы Malacostraca и Hexanauplia). Единственный представитель класса паукообразных (Arachnida; Acari) ― клещ Rhombognathus notops (Gosse, 1855) ― обнаружен лишь дважды (по одному экземпляру в сборах 2016 и 2017 гг.). Rapana venosa служит субстратом для развития разнообразных водорослей ― благоприятного местообитания для эпифитона, что обуславливает высокую численность и разнообразие ракообразных в этом биотопе. Наибольшее таксономическое разнообразие отмечено для класса Malacostraca ― 25 видов, относящихся к 22 родам 19 семейств. Членистоногие представлены двумя основными экологическими группами (седентарные и подвижные эпибионты). Наибольшее видовое разнообразие Arthropoda присуще свободноживущим подвижным формам (23 вида). Седентарные формы, явно уступая по количеству видов (4), доминируют по численности (86 %) и биомассе (94 %). Единственный представитель Cirripedia ― Amphibalanus improvisus (Darwin, 1854) ― является самым распространённым (53 % общей численности) и массовым ракообразным и вносит наиболее существенный вклад в биомассу (91,8 %) в консорции Arthropoda. Более 50 % видов Arthropoda в консорции рапаны — полифаги; фитофаги составляют 21 %, а детритофаги ― 29 % общего числа видов членистоногих. Единственный взрослый экземпляр эктопаразита рыб ― изоподы Elaphognathia bacescoi (Kussakin, 1969) ― найден в консорции песчаной рапаны на глубине 8 м в бухте Голубая (г. Севастополь). Все обнаруженные 27 видов Arthropoda присутствуют в консорции песчаной экоморфы R. venosa, и только 3 вида отмечены на скальной рапане. Различия в составе консорции двух экоморф R. venosa можно объяснить преимущественно большим развитием эпифитов и пониженной динамикой водных масс в зонах обитания песчаной рапаны в районе Севастополя. Благодаря своему таксономическому разнообразию, численности и биомассе Arthropoda являются важным элементом донного биоценоза, ассоциированного пространственно и трофически с особями самой крупной гастроподы Чёрного моря ― R. venosa.

Funchal Marine Biology Station: 20 years of research and promotion of Madeiran and Macaronesian marine biodiversity (NE Atlantic Ocean)

Event Abstract Back to Event Funchal Marine Biology Station: 20 years of research and promotion of Madeiran and Macaronesian marine biodiversity (NE Atlantic Ocean) Mafalda Freitas1, 2, 3, 4* and Manuel J. Biscoito1, 2, 3, 4 1 Estação de Biologia Marinha do Funchal, Portugal 2 Other, Portugal 3 Center for Marine and Environmental Sciences (MARE), Portugal 4 Observatório Oceânico da Madeira (OOM), Portugal The Funchal Marine Biology Station, on the Portuguese island of Madeira, is a research centre owned by the Municipality of Funchal and dedicated to research and education in marine sciences. It was inaugurated on September 28th, 1999 and its main goals are to develop the sciences and technologies of the sea, particularly, biology and ecology of coastal and deep sea waters. The Station is the base for the Marine Biology team of the Natural History Museum of Funchal and the Faculty of Life Sciences of the University of Madeira. These two teams participate in several research projects including studies on the fish and crustacean diversity of Macaronesian deep waters, coastal biology and ecology, biology and migration of sea turtles and marine pelagic birds’ biology and migration. Simultaneously, the Station also carries out educational activities to promote knowledge about sea habitats and environmental education, either in an institutional way, or working in collaboration with other public and private entities. During the last 20 years the Station has contributed with 46 scientific papers, 20 research projects, 30 scientific campaigns and expeditions, 14 didactic publications, 2 temporary exhibitions, and has received more than 12,000 visitors in guided tours. The didactic activities in 2018 are the object of this presentation. Keywords: Funchal Marine Biology Station, research, promotion, Madeira Island, Marine Biodiversity, Didactic activities Conference: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) , Braga, Portugal, 9 Sep - 12 Sep, 2019. Presentation Type: Oral Presentation Topic: Ecotourism, Environmental Education, Citizen Science and Dissemination of Science Citation: Freitas M and Biscoito MJ (2019). Funchal Marine Biology Station: 20 years of research and promotion of Madeiran and Macaronesian marine biodiversity (NE Atlantic Ocean). Front. Mar. Sci. Conference Abstract: XX Iberian Symposium on Marine Biology Studies (SIEBM XX) . doi: 10.3389/conf.fmars.2019.08.00033 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2019; Published Online: 27 Sep 2019. * Correspondence: Mx. Mafalda Freitas, Estação de Biologia Marinha do Funchal, Funchal, Portugal, mafalda.freitas@cm-funchal.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Mafalda Freitas Manuel J Biscoito Google Mafalda Freitas Manuel J Biscoito Google Scholar Mafalda Freitas Manuel J Biscoito PubMed Mafalda Freitas Manuel J Biscoito Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Diversity and distribution of peracarid crustaceans (Malacostraca) from the abyss adjacent to the Kuril-Kamchatka Trench

During the KuramBio expedition in 2012, macrobenthos samples were collected with an epibenthic sledge from 12 sites on the abyssal plain of the Northwest Pacific Basin adjacent to the Kuril-Kamchatka Trench (KKT) and on the western slope of the KKT, at depths between 4830 and 5780 m. In terms of the peracarid fauna, the NW Pacific abyss was found to be one of the richest and densely populated deep-sea regions of the World Ocean. With 482 species, 168 genera, 61 families and 5 orders, the superorder Peracarida was found to be the most diverse and one of the most abundant macrobenthic taxa in the collection. Of the taxa found, 3 genera and 386 (80%) species were apparently new to science, 30 genera and the family Dendrotionidae (Isopoda) being recorded for the first time in the NW Pacific. The peracarid fauna composition at the abyssal depths of the KKT region was typical of the open, non-isolated abyssal plain. The Isopoda proved the most diverse and abundant peracarid order (245 species, 61.3% of the individuals), followed by the Amphipoda (79 species, 19.6%), Tanaidacea (77 species, 9.1%), the Cumacea (70 species, 9.7%), and the Mysida (11 species, 0.23%). The highest peracarid abundance (up to 1047 ind./1000 m2) was recorded on the western slope of the trench, abundances at the abyssal plain being lower (125–639 ind./1000 m2). The peracarid distribution in the area studied was affected by a complex of various factors, the food availability reflected in the Particular Organic Matter (POM) flux belonging to the most important ones. Specifically, increases in the peracarid abundance and species richness corresponded in most cases with a high sediment organic carbon content or the high surface productivity level in the area. As indicated by the sediment composition, the food input to the deep-sea system apparently differed between the sites sampled. On the trench slope, accumulation of organic debris, transported down the slope from shallower regions, played an apparently major role. The abyss in the northern and in the southern parts of the area sampled is influenced by the high surface productivity, resulting from the regional hydrography. The area east of the Middle Kuril Islands is likely influenced by the organic material transported from the Sea of Okhotsk through the Kuril Straits.

Exceptional biodiversity of the cryptofaunal decapods in the Chagos Archipelago, central Indian Ocean

The Chagos Archipelago is geographically remote and isolated from most direct anthropogenic pressures. Here, we quantify the abundance and diversity of decapod crustaceans inhabiting dead coral colonies, representing a standardised microhabitat, across the Archipelago. Using morphological and molecular techniques we recorded 1868 decapods from 164 nominal species within 54 dead coral colonies, but total species estimates (Chao1 estimator) calculate at least 217 species. Galatheids were the most dominant taxa, though alpheids and hippolytids were also very abundant. 32% of species were rare, and 46% of species were found at only one atoll. This prevalence of rarer species has been reported in other cryptofauna studies, suggesting these assemblages maybe comprised of low-abundance species. This study provides the first estimate of diversity for reef cryptofauna in Chagos, which will serve as a useful baseline for global comparisons of coral reef biodiversity.

The parasite community of the sharks Galeus melastomus, Etmopterus spinax and Centroscymnus coelolepis from the NW Mediterranean deep-sea in relation to feeding ecology and health condition of the host and environmental gradients and variables

The parasite communities of sharks have been largely neglected despite the ecological importance and vulnerability of this group of fishes. The main goal of the present study is to describe the parasite communities of three deep-dwelling shark species in the NW Mediterranean. A total of 120 specimens of Galeus melastomus, 11 Etmopterus spinax and 10 Centroscymnus coelolepis were captured at 400–2200m depth at two seasons and three localities off the mainland and insular slopes of the Balearic Sea. Environmental and fish biological, parasitological, dietary, enzymatic and histological data were obtained for each specimen, and the relationships among them tested. For G. melastomus, E. spinax and C. coelolepis a total of 15, two and eight parasite species were respectively recovered. The parasite community of G. melastomus is characterized by high abundance, richness and diversity, and the cestodes Ditrachybothridium macrocephalum and Grillotia adenoplusia dominate the infracommunities of juvenile and adult specimens, respectively. A differentiation of parasite communities, linked to a diet shift, has been observed between ontogenic stages of this species. E. spinax displays a depauperate parasite community, and that of C. coelolepis, described for the first time, shows moderate richness and diversity. Detailed parasite-prey relationships have been discussed and possible transmission pathways suggested for the three hosts. Parasites were mostly related to high water turbidity and O2 levels, which enhance zooplankton proliferation and could thus enhance parasite transmission. The nematodes Hysterothylacium aduncum and Proleptus obtusus were linked to high salinity levels, as already reported by previous studies, which are associated to high biomass and diversity of benthic and benthopelagic crustaceans. A decrease of acetylcholinesterase activity and lower hepatosomatic index, possibly linked to infection-related stress, have been observed. Lesions associated to encapsulated larvae of G. adenoplusia have been observed in the muscle of G. melastomus, especially in the tail region, which can be indicative of the hunting strategy of its final host and may compromise the escape response of G. melatomus thus facilitating parasite transmission.

Diversity and ecology of crustaceans from shallow rocky habitats along the Mediterranean coast of Egypt

Spatio-temporal patterns of the distribution of crustaceans from shallow hard bottoms along the Alexandria coast (Egypt, Mediterranean Sea) were studied during a complete year cycle and also in relation to potential drivers of change (both biotic and abiotic), including variation in habitat-forming species. Overall, the crustacean assemblages appeared poor, including only 14 species belonging to Amphipoda (five species), Isopoda (five species), Tanaidacea (two species), Cirripedia and Decapoda (one species each). The distribution patterns of crustacean assemblages appeared significantly variable both in the spatial and in the temporal dimension on a rather unpredictable basis, albeit variation was related to changes in dominant algal and invertebrate habitat formers. High variability and low species richness observed suggest that the analyzed assemblages are selected by local unfavorable environmental conditions. In fact, the crustacean hard bottom fauna is composed by a bulk of tolerant forms, including the dominant Tanais dulongi, Apohyale perieri, Dynamene bidentata, Sphaeroma serratum, Elasmopus pectenicrus, and Jassa marmorata. Their spatio-temporal dynamics, as well as those of the remaining species, and correlations with the variation of habitat formers and environmental variables are reported. This is a baseline assessment of the crustacean diversity along the Mediterranean coast of Egypt, thus having paramount importance for understanding the predicted future changes of biodiversity for the area.

Effect of habitat fragmentation on abundance and diversity of seagrass-associated crustacean assemblage at Hurghada, Red Sea

Seagrass beds in Red Sea are increasingly subject to both natural and anthropogenic disturbance and fragmentation, resulting in an increase in the edge habitats. Consequently, the present study was designed to study the effect of habitat fragmentation of seagrass on the diversity and abundance of epiphytic crustaceans inhabiting seagrass canopies. For this purpose, two sites, containing different seagrass patch sizes, were selected for seasonal sampling during the period from mid-April 2015 to mid-January 2016 around Hurghada, Red Sea. Evaluations of the differences in crustacean assemblage structure, abundance and diversity between fragmented and continuous seagrass beds as well as the edge and center of the same seagrass patches were figured out. Overall, 33 crustacean species belong to 30 genera, 25 families, and 7 orders were recorded, from all different seagrass patches with a comparable temporal and spatial distribution; whereas all recorded crustacean species belong to class Malacostraca. Results indicated that large seagrass patches harbor higher crustacean’s densities than medium and small seagrass patches, which promote the assumption of the negative effect of seagrass fragmentation. The abundance of crustacean groups are also markedly increase in the large patches except decapods in one site. Reduction of habitat size led to reducing the number of crustacean species in both sites. However, Evenness values (J') showed that habitat fragmentation had no effect on diversity. THE Total crustaceans abundance is relatively increase toward the patch edge with a percentage of increase up to 18 %. However, crustacean species richness was insensitive to differences in patch edge-center microhabitat. Relation between seagrass shoot density/biomass and the total crustacean abundance also figured out in this study.

Composição e distribuição de crustáceos decápodes associados í­Â pesca do camarão-sete-barbas Xiphopenaeus kroyeri (Heller, 1862) no litoral norte do Estado de São Paulo

O objetivo deste estudo foi identificar, espacial e temporalmente, a composição e a diversidade de crustáceos decápodes capturados na pesca do camarão Xyphopenaeus kroyeri na enseada de Ubatuba. As coletas foram realizadas mensalmente, com barco de pesca camaroeiro, de setembro de 1995 a agosto de 1996 em oito transectos permanentes. No total, foram coletados 233.094 indiví­­duos pertencentes a 85 espécies. As maiores riquezas foram para os grupos Brachyura (49 espécies) e Anomura (16 espécies). Nos transectos IV e V foram encontrados os maiores valores de diversidade e o menor número de indiví­­duos do camarão X. kroyeri. Com relação í­Â similaridade, os transectos IV e V apresentam baixa similaridade em relação aos demais transectos devido í­Â s suas caracterí­­sticas, como localização na enseada e tipo de substrato. Estudos sobre a diversidade de fauna acompanhante de camarões de interesse comercial são imperativos para planos de manejo e conservação dos recursos naturais renováveis.

Soft-sediment crustacean diversity and distribution along the Portuguese continental shelf

This study analyzed the crustacean diversity, distribution and relationship with environmental factors in the western and the southern Portuguese continental shelf, between 10 and 200m depth. A total of 10,639 specimens belonging to 242 taxa from 90 families were identified, mostly amphipods (55.8% of the total taxa). The mysid Gastrosaccus spinifer and the amphipods Socarnes erythrophthalmus and Cheirocratus sundevallii were the most abundant and the amphipods Ampelisca brevicornis, Leucothoe incisa and Autonoe spiniventris were the most frequent species. The highest abundance and diversity was found in coarser sediments with up to 306 individuals per 0.1m2. Alpha diversity ranged from 1 to 28sp./0.1m2. Moreover, this study confirmed six previously doubtful first records and added an additional 19 new records to the Portuguese fauna. The results also confirmed the Portuguese coast as a transition zone of mixed Atlantic and Mediterranean faunas and exposed a noticeable North African and Macaronesian influence. A multivariate analysis based on the abundance of crustaceans revealed six affinity groups characterized by: (a) C. sundevallii, Guernea (Guernea) coalita and Sarsinebalia cristoboi on very coarse sands; (b) G. spinifer, Nototropis falcatus and Pontocrates arenarius on coarse sands; (c) Othomaera othonis, Processa modica modica and Animoceradocus semiserratus on heterogeneous medium sands; (d) A. brevicornis, Urothoe pulchella and Necalianassa truncata on fine sands; (e) Ampelisca pectenata, Bodotria scorpioides and Astacilla dilatata on heterogeneous fine sands and (f) Callianassa subterranea, Ampelisca tenuicornis and Ampelisca typica on muddy fine sands. Sediment grain-size and depth were the variables best related to the benthic crustacean spatial distribution patterns along the Portuguese continental shelf.

Holocene crustaceans from the Tarioba shell mound, Rio das Ostras, Rio de Janeiro, Brazil

Crustacean remains from the Tarioba shell mound (Sambaqui da Tarioba) archaeological site were investigated in order to produce a reference inventory of this taxonomic group. Information on past crustacean diversity is important for establishing baselines on biodiversity, as well as recovering paleoenvironmental information and comprehension of evolutionary change patterns for the Brazilian coast. The archaeological site was excavated by delayering the soil by artificial 10 cm sections which revealed five archaeological stratigraphic layers. A sample of mollusk shells for each of these layers was used for dating based on the C14 method. The results show an occupation period of 550 yr for the Tarioba shell mound, with dates ranging between 4,070 cal BP (beginning of occupation) and 3,520 cal BP (occupation ending) and record nine species of crustaceans from the shell mound. However, a reduction of biodiversity over time was found that was not statically significant. Therefore, it seems that patterns of composition, richness and distribution of crustaceans have been stable in the last 4,070 years BP.

Crustacean diversity in subtidal sediments of the highly urbanized Ría de Ferrol (Galicia, NW Spain)

Crustacean diversity in subtidal sediments of the highly urbanized Ría de Ferrol (Galicia, NW Spain)

Taxonomic diversity of crustaceans in Yellow Sea and Bohai Sea

Taxonomic diversity of crustaceans in Yellow Sea and Bohai Sea

Effect of water chemistry on zooplanktonic and microbial communities across freshwater ecotones in different macrophyte-dominated shallow lakes

&lt;p&gt;Complex interactions between zooplankton and microbial food webs are vital to the ecosystem ecology of shallow lakes. However, little is known about how horizontal changes in environmental conditions may influence microbial and metazoan communities in shallow lakes. The specific goals of the study were i) to describe environmental variables responsible for the distribution of bacteria, flagellates, ciliates and crustaceans in an adjacent canal, ecotone and reservoir (littoral-pelagic zone) in two different types of lakes (&lt;em&gt;Ceratophyllum&lt;/em&gt;-dominated and &lt;em&gt;Potamogeton&lt;/em&gt;-dominated lakes); ii) to determine whether the contact zone waters differ in hydrochemical and biological terms from the waters of the canal and the open water zone; iii) and to evaluate the influence of particular macro-habitats (canal, canal/reservoir, littoral and pelagic zone) on the interactions between components of the planktonic food web. We studied four shallow, eutrophic lakes in Polesie Lubelskie (eastern Poland). The highest diversity and abundance of microorganisms and crustaceans were observed in the canal-reservoir contact zone, while the lowest values were noted in the pelagic zone. Hence, the contact zone in the investigated lakes could fulfil the function of an ecotone, distinguished by a significant increase in biodiversity, abundance, and species specificity of micro- and macroorganisms. Weak relations between food web components were found in the &lt;em&gt;Ceratophyllum&lt;/em&gt;-dominated lakes, where environmental variables explained the bulk of the total variance in plankton abundance, whereas in the &lt;em&gt;Potamogeton&lt;/em&gt;-dominated lakes, where environmental variables had a minor role in the total variance in plankton abundance, strong predator-prey relations were noted. Spatial structure of habitats proved to be another important factor for relationships between food web components, as our study indicated that habitat complexity can reduce negative correlations between food web components. Our study contributes to knowledge of the functioning of eutrophic lakes in the current era of increasing eutrophication caused by climate change and human activity.&lt;/p&gt;

Crustacean diversity and conservation value indexes in pond assessment: implications for rare and relict species

espanolLas charcas y pequenos ambientes acuaticos juegan un papel importante en la conservacion de la biodiversidad y para salvaguardar las mas valiosas es fundamental reconocer los habitats que albergan especies relictas, poco comunes o en riesgo de extincion. Esto se valora normalmente en los organismos superiores, pero apenas se ha tenido en cuenta en las comunidades de crustaceos de las charcas que se evaluan por la riqueza de especies o la diversidad, considerando todas las especies por igual. En este trabajo hemos analizado los patrones de diversidad de crustaceos en diversos tipos de charcas mediterraneas en relacion con gradientes hidrologicos y medioambientales con las aproximaciones clasicas, pero ademas proponemos un nuevo indice dirigido a evaluar la conservacion de estos habitats basado en la importancia biogeografica y en la rareza de los crustaceos presentes (CCVI, Crustacean Conservation Value Index). En nuestro estudio de 150 charcas hemos observado que, aunque el grupo de charcas permanentes presenta un numero total mayor de especies de crustaceos que las temporales, a escala local las diferencias no son tan claras, y algunas charcas temporales presentaron los valores mas altos de riqueza de especies. Sin embargo, cuando se comparan cinco tipologias de charcas (3 tipos de charcas temporales y 2 de permanentes) en un gradiente de menor a mayor hidroperiodo y condiciones ambientales mas estables, observamos que tanto la riqueza de especies como la diversidad y otros parametros relacionados, si que aumentan con el grado de estabilidad propio del tipo de charca, tanto dentro de las temporales como de las permanentes. Por otro lado nuestros resultados ponen de manifiesto la importante contribucion de indices basados en el interes biogeografico y la rareza de las especies, en la identificacion de los lugares prioritarios para la conservacion de la biodiversidad. El indice propuesto utilizado en este estudio pone de relieve el interes y singularidad de ciertas charcas temporales muy efimeras, con pocas especies tal vez, pero claves en la conservacion de especies con alto riesgo de extincion. Las charcas temporales alcanzan un CCVI acumulado tres veces superior a las permanentes. La riqueza de especies puede ser util como metrica para identificar habitats prioritarios o definir un mejor estado ecologico dentro de habitats con un tipo similar de comunidad, sin embargo el indice de valor para la conservacion (CCVI) incluye otros aspectos de la biodiversidad relevantes para conservar aquellos habitats que albergan la fauna ancestral u originaria del lugar. Esta fauna es la que presenta ahora mas riesgo de extincion y debe tener mas puntuacion en los indices usados para determinar las areas prioritarias para la conservacion, ya que el incremento de las actividades humanas favorece cada vez mas las especies oportunistas o invasoras que las estan desplazando. EnglishPonds are important for the conservation of biodiversity. In order to safeguard them, it is essential to identify the habitats that sustain relict, rare or vulnerable species. This tactic has been utilized in communities of higher organisms but is rarely employed in pond crustacean communities, which are evaluated by species richness or diversity indexes in which all species are weighted equally. We have examined crustacean diversity in relation to environmental gradients in 150 Mediterranean ponds and propose a crustacean conservation value index (CVVI) for ponds. Under this index, species are scored based on the relictness and biogeographical significance of the taxonomic group to which they belong, as well as on their rarity or endemicity. In our study, permanent ponds showed a higher accumulated number of crustacean species than temporary ponds; however, local species richness was not consistently higher in permanent ponds, and the highest species richness was in fact found in temporary ponds. However, when ponds were subdivided by type into three groups of temporary ponds and two groups of permanent ones, species richness and diversity parameters tended to increase with an increasing degree of stability in both temporary and permanent ponds. In contrast, the accumulated CCVI was more than three times higher for groups of temporary ponds. A comparison of CCVIs revealed the importance and singularity of temporary pond fauna, indicating that species richness must not be the only criterion used to prioritize the conservation of habitats. Within a homogeneous pond typology, species richness could be a useful parameter for identifying priority habitats; however, the conservation value index per species includes other aspects of biodiversity more suitable to preserve locations with ancestral or original regional fauna. These fauna are currently endangered and should be prioritized for conservation, as increasing human activity favors the opportunistic and invasive species that are displacing them.

Carcinofauna bêntica estuarina de dois manguezais da costa amazônica maranhense, Brasil

RESUMO Este estudo teve por objetivo caracterizar a diversidade carcinológica de dois manguezais (igarapés Buenos Aires e Tronco) da Baía de São Marcos, na costa amazônica maranhense, Brasil. Foram realizadas quatro coletas trimestrais entre setembro de 2011 a junho de 2012. Em cada coleta foram analisados três pontos por área (zona 1, zona 2 e zona 3), totalizando 24 amostras. O material biológico foi coletado por meio de arrastos com rede do tipo puçá, catação manual e técnica de braceamento. Paralelamente à coleta do material biológico, foram verificados a salinidade, temperatura e oxigênio dissolvido de cada área analisada. Para avaliar a similaridade de agrupamento entre as zonas dos manguezais foi aplicada a análise de cluster e consecutiva elaboração de dendrogramas. Foi coletado um total de 873 indivíduos, representando nove famílias e 21 espécies, das quais Ocypodidae e Penaeidae foram as mais abundantes. Em relação à distribuição espacial, percebe-se que Clibanarius vittatus (Bosc, 1802), Clibanarius tricolor (Gibbes, 1850), Clibanarius foresti Holthuis, 1959 e Uca maracoani (Latreille, 1802) se restringiram à primeira zona dos dois manguezais, enquanto outras dez espécies foram observadas por todo o manguezal, o que pode estar intimamente relacionado ao seu hábito de vida. De um modo geral, o igarapé Buenos Aires apresentou maior número de espécies em relação ao igarapé Tronco, no entanto, existe grande similaridade faunística de crustáceos decápodes entre as duas áreas amostradas.

Refining the invertivore: diversity and specialisation in fish predation on coral reef crustaceans

Crustaceans are one of the most influential groups in aquatic trophic networks by providing a major connection between primary production and higher consumers. Although coral reefs support a high diversity and abundance of crustaceans and crustacean predators, their trophic interrelationships remain unclear. Using predator gut content analyses, we investigated trophic relationships between Crustacea and adult fishes of the family Labridae, which are one of the most abundant and diverse families of marine crustacean predators. Crustaceans were present within the guts of 93 % of the 30 wrasse genera investigated. We found a distinct division between micro- and macro-crustacean predators: wrasses 90 mm SL displayed a predominantly macro-Crustacea diet. Notably, micro-crustacean predators tended to specialise on certain crustacean taxa, whereas macro-crustacean predators consumed mostly brachyurans. Our findings highlight complex patterns of feeding diversity within crustacean predators that prompt a more nuanced approach to defining the role of crustacean-feeding fishes in coral reef trophodynamics.