Diversity and microstructure of quitons (Mollusca: Polyplacophora) from the Caribbean of Costa Rica

Diversity and microstructure of quitons (Mollusca: Polyplacophora) from the Caribbean of Costa Rica. The polyplacophorans of the coral reef on the Caribbean coast of Costa Rica have been insufficiently studied. The examination of coral rubble accumulated in the shallow sublitoral waters on four collection stations in Provincia Limón revealed a higher diversity of chitons than was documented. From the country eight species were previously known: Ischnochiton erythronotus (C.B. Adams 1845); Ischnoplax pectinata (Sowerby 1840); Stenoplax boogii (Haddon 1886); S. purpurascens (C.B. Adams 1845); Acanthopleura granulata (Gmelin 1791); Chiton marmoratus Gmelin 1791; C. tuberculatus Linnaeus 1758 and Acanthochitona rhodea (Pilsbry 1893). This study added five more species that are reported here for the first time: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954 and Cryptoconchus floridanus (Dall 1889).     

Trematode larvae in snails of Lake Glubokoe

In the Augusts of 1984 and 1985, 6 species of snails in Lake Glubokoe were investigated: Viviparus viviparus (Linne, 1758), Lymnaea ovata (Draparnaud, 1805), L. stagnalis (Linne, 1758), L. corvus (Gmelin, 1791), Planorbis planorbis (Linne, 1758), and Planorbarius corneus (Linne, 1758), which were found to be infected by 9 species of trematode larvae. V. viviparus showed the highest rate of infection — 48.15% ± 6.8. The larvae of trematodes belonging to the families Echinostomatidae and Plagiorchidae predominate in the snails of the lake.     

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.     

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.     

Establishing mollusk colonization and assemblage patterns in planted mangrove stands of different ages in Lingayen Gulf,Philippines

We investigated the assemblage patterns and species composition of infaunal mollusks in different ages of planted mangroves (6-, 8-, 10-, 11- and 18-year old) in Lingayen Gulf, northwestern Philippines. The study aimed to determine if the mollusk assemblage was associated with the developing forest and if such patterns could provide evidence for restoration of habitat functionality. A total of 11 mollusk species were recorded. Only two species, Cerithidea cingulata (Gmelin, 1791) and Nerita polita (Linnaeus, 1758), consistently appeared in all stands where the former had increased biomass in maturing stands and the latter peaked in intermediate age stands. Vegetation structure and biomass, and sediment characteristics changed as plantations matured. Likewise, mollusk assemblages (based on species composition and biomass) significantly varied among different age stands. Such changes in assemblage patterns were correlated with vegetation and sediment characteristics. The groupings of mollusks species in the different stands can be categorized into: decreasing (species that have initially high biomass but disappeared in older stands); no detectable change (species that did not show any change in biomass); peaking (species that initially had low biomass, peaked at intermediate stands, and then diminished in mature stands; and, increasing (species that have increasing biomass with maturing stands). In summary, this study affirmed: (1) rehabilitated mangroves with increased forest structure and biomass can be effective in facilitating infaunal colonization; and (2) mollusk assemblage patterns changed as stands grow older.     

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.     

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.     

18S ribosomal DNA sequences provide insight into the phylogeny of patellogastropod limpets (Mollusca: Gastropoda)

To investigate the phylogeny of Patellogastropoda, the complete 18S rDNA sequences of nine patellogastropod limpets Cymbula canescens (Gmelin, 1791), Helcion dunkeri (Krauss, 1848), Patella rustica Linnaeus, 1758, Cellana toreuma (Reeve, 1855), Cellana nigrolineata (Reeve, 1854), Nacella magellanica Gmelin, 1791, Nipponacmea concinna (Lischke, 1870), Niveotectura pallida (Gould, 1859), and Lottia dorsuosa Gould, 1859 were determined. These sequences were then analyzed along with the published 18S rDNA sequences of 35 gastropods, one bivalve, and one chiton species. Phylogenetic trees were constructed by maximum parsimony, maximum likelihood, and Bayesian inference. The results of our 18S rDNA sequence analysis strongly support the monophyly of Patellogastropoda and the existence of three subgroups. Of these, two subgroups, the Patelloidea and Acmaeoidea, are closely related, with branching patterns that can be summarized as [(Cymbula + Helcion) + Patella] and [(Nipponacmea + Lottia) + Niveotectura]. The remaining subgroup, Nacelloidea, emerges as basal and paraphyletic, while its genus Cellana is monophyletic. Our analysis also indicates that the Patellogastropoda have a sister relationship with the order Cocculiniformia within the Gastropoda.     

Confirmed occurrence of the Cusk-eel <Emphasis Type="Italic">Ophidion barbatum</Emphasis> (Osteichthyes: Ophidiidae) from the Coast of Tunisia (Central Mediterranean)

This paper reports the second record but also the first substantiated record of cusk-eel Ophidion barbatum (Linnaeus, 1758) from the northern coast of Tunisia, 168 mm in total length and weighing 18.3 g. The specimen is described including morphometric measurements and counts. Differences from its close relative species O. rochei (Linnaeus, 1758) are pointed out that confirm the occurrence of O barbatum in the Tunisian waters. This finding constitutes the northernmost extension range of the species in the area.     

Endorsing Darwin: global biogeography of the epipelagic goose barnacles Lepas spp. (Cirripedia,Lepadomorpha) proves cryptic speciation

It was Darwin that noted the large intraspecific diversity of the goose barnacle Lepas Linnaeus, 1758 and thought about distinct regional varieties. Today, biogeographic compartmentation is known from marine species, but data from globally occurring species remain scarce. We analysed inter‐ and intraspecific divergence within the epipelagic rafter Lepas from tropical and temperate oceans by means of two mitochondrial and one nuclear DNA marker. Besides phylogenetic relations, we resolved biogeography and controlling factors. Inhabiting the Southern Hemisphere, Lepas australis Darwin, 1851 shows separate populations from coastal Chile and from circum‐Antarctic waters, most probably related to temperature differences in the current systems. The cosmopolitan Lepas anatifera Linnaeus, 1758 displays four regional subgroups (coastal Chile, Northeast Pacific/Oregon, the Southern Hemisphere Indopacific, and the Atlantic), and a global group, which might be an ancestral stem group. The differentiation reflects vicariance effects rooted in geological history: the closure of the Neogene Tethys in the Middle East and at the Panama Isthmus, the installation of the cool Benguela Current, differing Pleistocene currents and temperatures, and modern current systems. The extreme ecological generalists Lepas anserifera Linnaeus, 1767 and Lepas pectinata Spengler, 1793 are not differentiated, and might represent true global species. In conclusion, compartmentation of the oceans acts at the species level according to ecospace limits. For Lepas, the multitude of barriers favours allopatric speciation.     

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.     

A cascade of warming impacts brings bluefin tuna to Greenland waters

Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator‐prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species in ecological isolation from others. Here, we show that a large highly migratory top predator fish species has entered a high latitude subpolar area beyond its usual range. Bluefin tuna, Thunnus thynnus Linnaeus 1758, were captured in waters east of Greenland (65°N) in August 2012 during exploratory fishing for Atlantic mackerel, Scomber scombrus Linnaeus 1758. The bluefin tuna were captured in a single net‐haul in 9–11 °C water together with 6 tonnes of mackerel, which is a preferred prey species and itself a new immigrant to the area. Regional temperatures in August 2012 were historically high and contributed to a warming trend since 1985, when temperatures began to rise. The presence of bluefin tuna in this region is likely due to a combination of warm temperatures that are physiologically more tolerable and immigration of an important prey species to the region. We conclude that a cascade of climate change impacts is restructuring the food web in east Greenland waters.     

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.     

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.     

中国草螟属一新种(鳞翅目,螟蛾科,草螟亚科)

描述了中国草螟属1新种--新牧草螟Crambus neopascuellus sp.nov.,给出了新种与该属模式种牧草螟Crambus pascuellus(Linnaeus,1758)的比较.模式标本保存在中国科学院动物研究所标本馆.     

THE GONADS OF MARGARITIFERA AURICULARIA (SPENGLER, 1793) AND M. MARGARITIFERA (LINNAEUS, 1758) (BIVALVIA: UNIONOIDEA).

A detailed study of the gonads of two endangered species of thegenus Margaritifera living in the Iberian Peninsula, Margaritiferaauricularia (Spengler, 1793) and Margaritifera margaritifera(Linnaeus 1758), based on macroscopic and histological observationsis presented. In both species, gonadal tissue occurs withinthe visceral mass without a specific location. In hermaphrodite specimens,male and female acini are mixed in the visceral mass but canbe clearly distinguished by detailed macroscopic study. The gonadaltopography and cycle of Margaritifera auricularia is described forthe first time, indicating that the species is a female hermaphroditeand that gametogenesis occurs from December to March. Fiftypercent of Margaritifera margaritifera specimens studied werehermaphrodites and 50% females. (Received 6 March 2000; accepted 5 June 2000)     

Home ranges and densities of medium-sized carnivores in south-east Finland, with special reference to rabies spread

Home ranges and densities of medium-sized carnivores were studied in south-east Finland by radio tracking. The species studied included potential vectors of rabies: the raccoon dogNyctereutes procyonoides (Gray, 1834), red foxVulpes vulpes (Linnaeus, 1758), European badgerMeles meles (Linnaeus, 1758) and domestic catFelis silvestris catus (Schreber, 1777). Home ranges of badgers were largest (mean 14.7 km²) and those of cats smallest (1.5 km²). Home ranges overlapped largely, both within and between species. Most home ranges were larger and population densities lower in south-east Finland compared with those in Western Europe. The pooled density of medium-sized carnivores with overlapping home ranges was, however, high, which may indicate a high risk of a rabies epizootic in this multi-host community. Rabies might also spread rapidly to new areas, because of the large home ranges and, consequently, long dispersal distances.     

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).