IL GAMBERO AMERICANO Orconectes limosus(Rafinesque),UN NUOVO DECAPODE NEARTICO NELLE ACQUE DOLCI DEL NORD ITALIA(Crustacea Decapoda Cambaridae)

The American Striped Cray Orconectes limosus(Rafinesque),a nearctic crustacean new in theitalian freshwaters(Crustacea Decapoda Cambaridae).The American Striped Cray Orconectes limosus,introduced in several countries of Central Europe,is also reported for the first time for Italy.This crayfishseems to become well established in the Iseo Lake(Northern Italy).The Author underlines the risk of a possibleterritorial expansion of this species in the Po river drainage.

Advancement of Studies on Vitellogenin of Crustaceans

[Objective]The paper briefly summarizes the gene cloning and molecular research progress of vitellogenin in crustaceans belonging to Decapod. [Method]The molecular characteristics of identified Vg proteins in crustacean are reviewed from the aspects of protein synthesis,molec- ular structure,phylogenetic evolution,hormonal regulation of gene expression and biological functions. [Result]The similarity of structure and func- tion in homologous protein are pointed out; phylogenetic relationships among molecules are analyzed; the main characteristics of Vg interspecific protein in Decapod are summarized,and the special parts different from other species are raised. [Conclusion]The study can offer some help for the further study of Vg gene,and provides theoretical basis for ovary development mechanism of crabs.

Heavy metal stress induced hyperglycemia in blue swimmer crab, Portunus pelagicus

The study was to find out the effect of cadmium and mercury on levels of hemolymph glucose, crustacean hyperglycemic hormone（CHH） and hepatopancreas glycogen in the blue swimmer crab Portunus pelagicus. The experiments were performed in both intact and eyestalk ablated crabs. Quantification of CHH was done by the indirect ELISA with the aid of primary anti-Carcinus maenas-CHH antibody. Higher glucose concentration was observed on exposure to 8×10^–6 of cadmium（（825.6±5.42） μg/m L） and 6×10^–6 of mercury（（90.5±6.25） μg/m L）after 48 h and 24 h respectively. Higher level of hemolymph glucose was observed in eyestalk intact crabs on exposure to cadmium and mercury than eyestalk ablated crabs. Decrease in the levels of CHH was observed in both eyestalk intact and ablated crabs on heavy metal exposure. Decline of the hepatopancreas glycogen level was also witnessed with the exposure to heavy metal, which validated its utilization in the production of glucose. Thus this study brings to light, the variations in hemolymph glucose, CHH and hepatopancreas glycogen on heavy metal stress. These carbohydrate metabolites can be used as biomarkers in assessing heavy metal contamination in water bodies.

Palaeoecological Analysis of Trace Fossil Sinusichnus sinuosus from the Middle Triassic Guanling Formationin Southwestern China

The Luoping Biota discovered from the early Middle Triassic （Anisian） Guanling Formation of southwestern China represents a fully recovered shallow marine ecosystem, marking the end point of Early Triassic biotic recovery following the end-Permian mass extinction. Contemporaneously preserved are prolific trace fossils, which offer good opportunities to understand the palaeoecology of marine invertebrates from a fully recovered shallow marine ecosystem. Here we present a newly discovered sinuous branching burrow from the fossil-bearing unit in Member II of the Guanling Formation. Several features, including the horizontal regular sinuous nature, the branching pattern, typical H-junction, and the small wavelength/amplitude ratio of these sinuous structures within the burrow systems justify assignment of these traces as Sinusichnus sinuosus, a trace possibly produced by decapod crustaceans. Close association ofS. sinuosus with Rhizocorallium commune suggests a deposit-feeding strategy of these trace makers. The newly reported Anisian material from the Guanling Formation in Luoping represents first report of Sinusichnus from South China. The global record of Sinusichnus occurrence suggests that these burrows might have an older history than Early Middle Triassic.

Effects of twine material on the marine debris and relative ghost fishing of portunid hoop (tangle) nets

Portunids are important to recreational fisheries in Australia and typically are harvested by baited gears.Most of these baited gears are considered environmentally benign,although small conical hoop(tangle)nets fished in southeastern Australia sometimes are damaged and lose twine,which becomes marine debris.Substituting conventional multifilament polyamide(PA)twine with alternative multi-monofilament and monofilament PA twines in hoop nets can dramatically reduce marine debris,but there remain unanswered questions concerning the relative fishing power of alternative twines among derelict hoop nets.This study addresses the shortfall in data by comparing the efficiencies and damage to replicate hoop nets made from the three twines and left to fish for short(one and two days),medium(three to five days)and long(ten and fourteen days)soaks.Irrespective of twine material or soak time,all hoop nets entangled the same numbers of giant mud crabs,Scylla serrata implying catch saturation within two days.Only four other animals were caught(all yellowfin bream,Acanthopagrus australis)and all died.At least some replicates of all hoop nets were damaged and lost twine,but this was greatest among the multifilament(up to a maximum of 9.3m hoop-net deployment−1),followed by the multi-monofilament(up to 7.4m hoop-net deployment−1)and monofilament hoop nets(1.4m hoop-net deployment−1).Replacing the existing multifilament twine in hoop nets with monofilament when targeting S.serrata would maintain catches and minimise marine debris during conventional soaks,without increasing ghost fishing over the short term.