Elasmobranch captures in shrimps trammel net fishery off the Gulf of Gabès (Southern Tunisia,Mediterranean Sea)

Small‐scale fisheries are generally promoted as a sustainable alternative to large‐scale industrial fisheries. However, there is recent growing evidence that small‐scale fisheries may be the largest threat to marine species of conservation concern. The objective of this study was to evaluate the potential impact of the trammel net fishery on elasmobranchs in the Gulf of Gabès, Southern Tunisia. Data are based on 191 shrimp trammel net set (40 mm stretched mesh size) surveys conducted aboard commercial fishing vessels from May to July 2009. Five species of the small coastal elasmobranchs (Mustelus mustelus (Linnaeus, 1758), Mustelus punctulatus Risso 1827, Dasyatis pastinaca (Linnaeus, 1758), Dasyatis marmorata (Steindachner, 1892) and Torpedo torpedo (Linnaeus, 1758)) and two species from the large coastal shark (Carcharhinus plumbeus (Nardo, 1827) and Carcharhinus brevipinna (Müller & Henle, 1839)) were recognized as by‐catch in this fishery. Elasmobranch by‐catch was dominated by sharks (90.3%), smoothhound sharks Mustelus sp. being by far the most important (88.9%) and reflecting their abundance in the area; 58% of the sets caught at least one specimen, with 4.8 ± 1.3 caught per set. Captures were composed essentially of neonate and juvenile sharks, while the batoids were dominated by mature individuals. This study shows that shrimp trammel nets represent a considerable source of mortality for early life stages of elasmobranch species in the Gulf of Gabès. Additionally, there was a high density of neonates and small juvenile M. mustelus in the Sfax zone, suggesting that these nearshore waters are a nursery grounds for smoothhound sharks. Further research should focus on the incidents of by‐catch and evaluate the potential solutions to allow trammel net fisheries to coexist alongside the elasmobranch species.     

Siliceous scales of filose-amoebae (Pompholyxophryidae,Rotosphaerida) from deep Southern Ocean sediments,including first records for the Southern Hemisphere

The world of protists remains largely unexplored. A thorough electron-microscopic investigation of a few microlitres of deep-sea sediment from 2,964 m water depth near the South Sandwich Islands (Southern Ocean) revealed siliceous scales of filose-amoeba protist species, two of which have not been reported previously from Antarctica or from elsewhere in the Southern Hemisphere. However, all the species are known from other oceans and, in one case, from freshwater habitats. The Antarctic protistan scales belong to four species of filose amoebae: Pinaciophora fluviatilis Greef 1869, Pinaciophora denticulata Thomsen 1978, Pinaciophora multicosta Thomsen 1978 and Rabdiaster reticulata (Thomsen 1979) Mikrjukov 1999 nov. comb. Our study shows that (1) none of the species has been recorded from the Australasian biogeograpical region, (2) Pinaciophora multicosta and Rabdiaster reticulata are new records for the Southern Ocean and for the Southern Hemisphere as a whole, (3) prior to this investigation, Pinaciophora multicosta had been reported once only, from the Baltic Sea (Europe). These results highlight the problem of undersampling in the study of the global distribution of protists.     

Length–weight and length–length relationships for 10 pelagic fish species from the Adriatic Sea (Croatia)

Length–weight and length–length relationships are described for 10 of the most important and most frequent small, middle‐size and large pelagic fish species from the Adriatic Sea, namely Sardina pilchardus Walbaum 1792, Sardinella aurita Valenciennes 1847, Sprattus sprattus Linnaeus 1758, Engraulis encrasicolus Linnaeus 1758, Belone belone Linnaeus 1761, Scomber scombrus Linnaeus 1758, Scomber japonicus Houttuyn 1780, Thunnus thynnus Linnaeus 1758, Auxis rochei Risso 1810 and Sarda sarda Bloch 1793. Length–length equations for converting size measurements: standard length (SL) and fork length (FL) to total length (TL) and vice versa, were linear.     

The Noctuoidea (Lepidoptera) described by Linnaeus

Linnaeus described 166 nominal species of Noctuoidea, of which 144 (86.7%) are currently used as valid names, 18 are synonyms, one is a homonym and three taxa remain unknown. Seven taxa were described solely from illustrations in contemporary literature. Lectotypes are designated for 139 (87.4%) of the 159 remaining taxa, 122 of them from the Linnaean collection in London, 13 from the Queen Ludovica Ulrica's collection in Uppsala, Sweden, and four from other contemporary collections. Two Linnaean senior synonyms are introduced: Hada plebeja comb. nov. (Linnaeus, 1761) for the current H. nana (Hufnagel, 1766) and Oeonistis altica (Linnaeus, 1768) comb. nov. for Oe. entella (Cramer, 1779). Erebus occiduus (Linnaeus, 1758) syn. nov. is a junior subjective synonym of E. crepuscularis (Linnaeus, 1758); L. marmorides (Cramer, 1775) Stat. rev. should be reinstated for Letis occidua auct. In two species pairs the Linnaean names have been interpreted incorrectly. The lectotype designation of Phalaena prasinana Linnaeus, 1758, by Lempke (1947) is invalid because the specimen is not syntypic. According to the new lectotype, Pseudoips prasinanus (Linnaeus, 1758) comb. nov. replaces P. faganus (Fabricius, 1781), and Bena bicolorana (Fuessly, 1775) comb. nov. is available for the other species. Abrostola triplasia (Linnaeus, 1758) Stat. rev. replaces A. trigemina (Werneburg, 1864), and for the other species A. triparlila (Hufnagel, 1766) should be reinstated. One neotype designation [Eilema complanum (Linnaeus, 1758)], one lectotype designation [Xylena exsolela (Linnaeus, 1758)], and precedence of a junior synonym [Ophideres fullonia (Clerck, 1764)] over its unused senior synonym are to be referred to the ICZN; until their decision the current usage must be followed. The identity of Mesapamea secalis (Linnaeus, 1758) stat. rev. corresponds to current usage, but, under presence of syntypic material, the recent neotype designation by Lempke (1988) will be referred to the ICZN. The revision is mainly based on the discovery that the insect pins and the way specimens are prepared give evidence of the authenticity of the material. Contrary to the views of earlier authors, Linnaeus had his labels with the specific name pinned against the bottom of the drawers by the specimen pin. Because the labels have been moved twice during subsequent curations, their present position is less indicative of the authenticity than has been previously suggested. The origin of the so-called n-labels is discussed.     

Koi herpesvirus infection in experimentally infected common carp Cyprinus carpio (Linnaeus, 1758) and three potential carrier fish species Carassius carassius (Linnaeus, 1758); Rutilus rutilus (Linnaeus, 1758); and Tinca tinca (Linnaeus, 1758) by quantitative real‐time PCR and in‐situ hybridization

Only single cells in the carrier fish species Carassius carassius (Linnaeus, 1758) for koi herpesvirus (KHV) are infected in contrast to large numbers in the susceptible species common carp Cyprinus carpio (Linnaeus 1758). Several species of the family Cyprinidae have been described as virus carrier species, showing no clinical signs of a KHV disease but able to transmit the virus to other susceptible fish. In this study, 72 common carp Cyprinus carpio (Linnaeus, 1758), 36 tench Tinca tinca (Linnaeus, 1758), 36 crucian carp Carassius carassius (Linnaeus, 1758) and 36 common roach Rutilus rutilus (Linnaeus, 1758) were experimentally infected with KHV (isolate “Israel”) by immersion and kept at 20°C. The fish were euthanized at 12 timepoints over a period of 90 days and virus DNA was quantified in tissues by a real‐time TaqMan PCR. Whereas KHV‐DNA was found in Cyprinus carpio for up to 90 days, the virus DNA was detectable only in single individuals of Rutilus rutilus, Tinca tinca and Carassius carassius for up to 25 days after experimental virus exposure. Tissue samples of Cyprinus carpio and Carassius carassius were screened by in‐situ hybridization. Positive signals were found in various organs of the common carp tested crucian carp. In the latter species a much smaller number of virus‐positive stained cells was detected compared to the infected carp.     

Weight–length relationships of some fish species of the Iberian Peninsula

This study reports weight–length relationships (WLR) for Salmo trutta (Linnaeus, 1758), Phoxinus phoxinus (Linnaeus, 1758), Chondrostoma Chondrostoma miegii (Steindachner, 1866), Barbus graellsii (Steindachner, 1866), Barbatula barbatula (Linnaeus, 1758) and Gobio gobio (Linnaeus, 1758). Specimens were collected by electrofishing during summer between 1996 and 1998. The b values in the WLR W = aL^b varied between 2.97 and 3.42. To the best knowledge of the authors, this study presents the first reference on WLRs for four of the species in Spanish waters.     

Identification of forensically important blow fly species (Diptera: Calliphoridae) in China by mitochondrial cytochrome oxidase I gene differentiation

Abstract Unambiguous and rapid sarcosaphagous insect species identification is an essential requirement for forensic investigations. Although some insect species are difficult to classify morphologically, they can be effectively identified using molecular methods based on similarity with abundant authenticated reference DNA sequences in local databases. However, local databases are still relatively incomplete in China because of the large land area with distinct regional conditions. In this study, 75 forensically important blow flies were collected from 23 locations in 16 Chinese provinces, and a 278‐bp segment of the cytochrome oxidase subunit I gene of all specimens was successfully sequenced. Phylogenetic analysis of the sequenced segments showed that all Calliphorid specimens were properly assigned into nine species with relatively strong supporting values, thus indicating that the 278‐bp cytochrome oxidase subunit one region is suitable for identification of Calliphorid species. The clear difference between intraspecific threshold and interspecific divergence confirmed the potential of this region for Calliphorid species identification, especially for distinguishing between morphologically similar species. Intraspecific geographic variations were observed in Lucilia sericata (Meigen, 1826) and Lucilia caesar (Linnaeus, 1758).     

Bioinvasion threatens the genetic integrity of native diversity and a natural hybrid zone: smooth‐shelled blue mussels (Mytilus spp.) in the Strait of Magellan

Smooth‐shelled blue mussels of the Mytilus edulis species complex are widely distributed bivalve molluscs whose introductions threaten native marine biodiversity (non‐indigenous species – NIS). The aim of the present study was to identify the species and hybrids of Mytilus present in the Magellan Region (southern Chile). Results indicate that three mussel species of the Mytilus edulis complex are found in the region – M. edulis, M. chilensis (or the Southern Hemisphere lineage of Mytilus galloprovincialis), and M. galloprovincialis of Northern Hemisphere origin. For the first time, alleles of the introduced M. trossulus are reported from the Southern Hemisphere. In the Strait of Magellan the native Pacific blue mussel, Mytilus chilensis and the native Atlantic blue mussel, Mytilus edulis, meet and mix at a natural hybrid zone (about 125 km in length). This is the first record of a natural Mytilus hybrid zone in the Southern Hemisphere and is also the first record of the co‐occurrence of genes from all four Mytilus species in any one region. These results contribute to the knowledge of the biodiversity and delimitation of mussel species in southern South America, and highlight how introduced species may threaten the genetic integrity of native species through hybridization and introgression.     

Does the recently introduced bumblebee Bombus terrestris (Apidae) threaten Australian ecosystems?

Abstract Native vegetation near Hobart in Tasmania was investigated to determine whether it was being invaded by the recently introduced large earth bumblebee, Bombus terrestris (Linnaeus, 1758). This species was found to be established in high numbers in a variety of vegetation types from coastal heath, through sclerophyll forest, and subalpine shrubberies up to an altitude of 1100 m. Hence, it has the potential to spread through much of Tasmania and temperate, mesic regions of mainland Australia. It is highly polylectic, foraging on at least 66 native plant species from 21 families. While the most heavily visited species produced abundant nectar, the lack of pre-dation on this species also allowed it to forage economically on small flowers in clusters. This foraging profile overlapped with those of all anthophilous insect families, all bee subgenera, and all species of nectarivorous birds which were encountered. Therefore, B. terrestris has the potential to compete with most native anthophiles and commercial honeybees. As it forages from some plant taxa which are not visited by the European honeybee, Apis mellifera Linnaeus, 1758, this species is impacting on plant-pollinator relationships which have previously been free from the effects of exotic bees.     

Diversity and temporal variations of the Hemiptera Auchenorrhyncha fauna in the Ajaccio region (France,Corsica)

Summary

During a one-year survey of the Auchenorrhyncha fauna in a maquis habitat of the Ajaccio region (Corsica), 37 species were listed including three alien species recorded in Europe in the last decades. The standard 658 bp mitochondrial COI barcode was obtained for 32 species, including 14 species never previously barcoded. Neighbor-joining analyses confirmed the delineation for all the species. However, comparisons with available sequences from mainland Europe showed that four species presented a significant intraspecific divergence (>3%), whereas a reduced interspecific divergence was found for another set of species. Complementary studies may therefore be necessary to better assess their taxonomic levels. Three species – Euscelis lineolata Brullé, 1832 (Cicadellidae), Philaenus spumarius (Linnaeus, 1758) (Aphrophoridae) and Latilica maculipes (Melichar, 1906) (Issidae) – accounted for up to 74.3% of the total insects collected. Although taxonomic interpretations using restricted sampling and COI sequences alone are not robust, the proportion of new sequences highlight the global lack of knowledge about the Auchenorrhyncha as a whole and the potentially presence of cryptic taxa in different clades.     

Niche overlap between juvenile flatfishes, Platichthys flesus and Solea solea, in a southern European estuary and adjacent coastal waters

The distribution and abundance patterns as well as the feeding ecology of two flatfishes, Platichthys flesus (Linnaeus, 1758) and Solea solea (Linnaeus, 1758), were studied in the Douro estuary and adjacent coastal waters (Portugal) in order to evaluate the niche overlap between these species. Fish were collected during sampling surveys conducted every 2 months between November 2000 and March 2002 using a 12‐m otter‐trawl with 18 mm stretched mesh size, at 12 sites within the estuary and six sites in the adjacent coastal area. The highest densities of P. flesus were registered in the middle estuary; a peak density of 9.12 ind 1000 m^?2 was obtained in October 2001. Solea solea densities were low compared with P. flesus; the highest values were also recorded in the middle estuary in October 2001. For both species, the proportion of juveniles was above 90% within the estuary. Highest densities of P. flesus and S. solea were recorded at sites with low water depth and high densities of crustaceans and polychaetes, the main food items in the diet of these species. High values of spatial and diet niche overlap were found between these two flatfishes (0.97 and 0.92, respectively).     

A molecular investigation of the genus Ecklonia (Phaeophyceae,Laminariales) with special focus on the Southern Hemisphere

Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.     

Biochemical studies on Brachionus plicatilis: hydrolytic enzymes,integument proteins and composition of trophi

In Terminos Lagoon, México, more than 80 fish species use the mangrove and seagrass habitats. We studied nekton dynamics in an inlet seagrass system and a more sheltered seagrass/mangrove system located behind a barrier island. Seasonal community biomass ranges from 0.6 to 5.2 g wet wt m^-2. For the two habitats together, there are 28 dominant species. Eleven species were common to both areas: Sphoeroides testudineus (Linnaeus, 1758), Archosargus rhomboidalis Linnaeus, 1758, A. probatocephalus (Walbaum, 1792), Arius felis (Linnaeus, 1766), A. melanopus (Gunther, 1864), Eucinostomus gula (Cuvier & Valenciennes, 1830), Bairdiella chrysoura (Lacépède, 1803), Orthopristis chrysoptera (Linnaeus, 1766), Chilomycterus schoepfi (Walbaum, 1792), Opsanus beta (Goode & Bean, 1879) and Lutjanus griseus (Linnaeus, 1758). Ten species used exclusively the inlet seagrass system: Urolophus jamaicensis (Cuvier, 1817), Haemulon aurolineatum (Cuvier, 1829), H. bonariense (Cuvier, 1830), H. plumieri (Lacépède, 1802), Anisotremus virginicus (Linnaeus, 1758), Odontoscion dentex (Cuvier, 1830), Corvula sanctae-luciae (Jordan, 1890), Nicholsina usta (Valenciennes, 1839), Stephanolepis hispidus (Linnaeus, 1766) and Diodon hystrix Linnaeus, 1758. Seven species were dominant only in the seagrass/mangrove system: Anchoa mitchilli (Cuvier & Valenciennes, 1848), Scorpaena plumieri Bloch, 1789, Cynoscion nebulosus (Cuvier & Valenciennes, 1830), Diapterus rhombeus (Cuvier & Valenciennes, 1830), Bairdiella ronchus (Cuvier & Valenciennes, 1830), Cichlasoma urophtalmus (Günther, 1862) and Acanthostracion quadricornis (Linnaeus, 1758). Comparative analysis showed that periodic variation in biomass and diversity of fish assemblages in seagrass and seagrass/mangrove habitats were synchronized with sizes and densities of population, season of the year (dry, wet, ‘nortes’), circulation pattern, and patterns of primary production (phytoplankton, Thalassia testudinum Konig, 1805; and Rhizophora mangle Linnaeus). This analysis allowed the definition of 3 life-cycle patterns with a clear nektonic ‘seasonal programming’ following the timing of primary production in these critical habitats: (1) marine species which spawn in or near the inlet with eggs and larvae transported into and distributed throughout the lagoon by the predominant currents; (2) estuarine-marine species which spawn in different habitats of the lagoon and use the seagrass/mangrove system as a nursery area, and (3) species which complete their life history in the inlet seagrass and/or seagrass/mangrove systems. EPOMEX Program Contribution No. 0026.     

Biological availability and humic properties of dissolved organic carbon in Lake Balaton (Hungary)

The nursery role of the Mondego estuary for marine fish species was studied between June 2003 and May 2004. The spatial and temporal distribution and abundance patterns of 0-group Dicentrarchus labrax (Linnaeus, 1758), Platichthys flesus (Linnaeus, 1758) and Solea solea (Linnaeus, 1758) were analyzed based on monthly sampling surveys in five stations along the estuarine gradient. Fishing took place during the night at low water of spring tides, using a 2 m beam trawl. The spatial patterns of estuarine colonization were different according to species. D. labrax showed a wider distribution, but the main nursery ground was the same as for S. solea. Highest densities of S. solea juveniles were found in oligohaline areas, with muddy bottoms and high benthic invertebrates availability, while P. flesus occurred mainly in the sandy uppermost areas. D. labrax was found in both these areas. Fish abundance in the estuary mainly reflected seasonal changes.     

Multiple origins of Southern Hemisphere Anemone (Ranunculaceae) based on plastid and nuclear sequence data

 Using two molecular data sets, the plastid atpB-rbcL intergenic spacer region and the nuclear ribosomal internal transcribed spacer regions (ITS), the taxonomic affinities of two newly available Anemone species from the Southern Hemisphere were tested. From previous work based on morphology and geographic distribution, it was assumed that A. tenuicaulis from New Zealand was most closely related to the Tasmanian A. crassifolia, whereas the affinity of A. antucensis from Chile and Argentina was regarded as uncertain. Analyses of molecular sequence data from these and 18 other species of Anemone s.lat. (with Clematis as outgroup) result in trees largely congruent with past analyses based on morphology and plastid restriction site data. They strongly support A. richardsonii and A. canadensis (with boreal distributions in the Northern Hemisphere) as paraphyletic to a well supported Southern Hemisphere clade consisting of A. antucensis and A. tenuicaulis. This group of four species is part of an otherwise predominantly Northern Hemisphere assemblage (subgenus Anemonidium s.lat., chromosome base number x=7), including A. narcissiflora, A. obtusiloba, A. keiskeana and A. (=Hepatica) americana. All other austral species included in the present sampling, A. crassifolia (Tasmania), A. knowltonia (=Knowltonia capensis), and A. caffra (both South African), form a separate clade, sister to A. (=Pulsatilla) occidentalis and other Northern Hemisphere anemones (subgenus Anemone s.lat., x=8). Possible phytogeographical links of the Southern Hemisphere species are discussed. Received April 23, 2001 Accepted October 4, 2001     

Chromosome numbers for three species of medicinal leeches (<Emphasis Type="Italic">Hirudo</Emphasis> spp.)

Karyological preparations were made from the testisacs of three medicinal leech species Hirudo medicinalis Linnaeus, 1758, H. verbana Carena, 1820 and H. orientalis Utevsky & Trontelj, 2005 . The samples originated from different populations in Azerbaijan, Kazakhstan, Russian Federation, Ukraine and Uzbekistan. The chromosome numbers were determined both from mitotic and meiotic stages of spermatogenesis using the propionic haematoxylin staining technique. All three species were found to have different haploid chromosome numbers: H. medicinalis 14, H. verbana 13 and H. orientalis 12, thus corroborating the validity of these taxa. The chromosomes can be classified as meta-, submetacentric and acrocentric. The chromosome numbers obtained are similar to that of the related species Haemopis sanguisuga (Linnaeus, 1758), which has 13 pairs.     

Goose barnacles hitchhike on satellite-tracked southern elephant seals

Goose barnacles (Lepas australis) attached to satellite-relay data loggers were carried by three southern elephant seals (Mirounga leonina) from Marion Island. Their movements across the Polar Frontal Zone are presented, providing further evidence that megafauna are potential vectors for the transport of species into the Southern Ocean.     

Preliminary assessment of discards survival in a multi‐species Mediterranean bottom trawl fishery

The EU Common Fisheries Policy (CFP) reform establishes a gradual landing obligation for stocks for which catch limits are set, and in the Mediterranean for species with Minimum Conservation Reference Size. However, the landing obligation will not apply for species with scientific evidence of high survival rates. Discards estimates usually assume that the whole discarded catch is dead or dies at sea. However, survival of individuals discarded at sea is substantial for several species. In the Mediterranean Sea, the information on this issue is very limited. The aim of this study is to perform a preliminary assessment of the short‐term survival of discards in the multi‐species bottom trawl fishery in the Eastern Ionian Sea, Greece. Experimental fishing was held in spring when no water column stratification was observed and in autumn when a seasonal thermocline was formed. The catch was sorted, the regularly discarded species/sizes were put in tanks and their survival was monitored in specific time intervals up to 72 hr. A seasonal effect was obvious with high mortality in autumn being attributed to high water temperatures. Survival was low or zero for most species, but was relatively high for certain species (e.g., annular seabream, Diplodus annularis (Linnaeus, 1758); European conger, Conger conger (Linnaeus, 1758); brown comber, Serranus hepatus (Linnaeus, 1758) among bony fishes) and broad taxonomic categories (elasmobranchs and most invertebrates) in spring or in both seasons. Poor survival was generally estimated for most species subject to the landing obligation (e.g., hake, Merluccius merluccius (Linnaeus, 1758)). The present study, even though preliminary, can be important for improving future works, for identifying species with high survival potential, and—to a lesser extent—for the implementation of the CFP.