Metal residues in flesh of edible blue crab,Callinectes amnicola,from a tropical coastal lagoon: Health implications

Metals such as cadmium (Cd), lead (Pb), zinc (Zn), and copper (Cu) were estimated in the flesh of the edible blue crab Callinectes amnicola from selected areas of the Lagos Lagoon, Nigeria (i.e., Makoko, Iddo, Okababa, Ikoyi, and Ajah) for 18 months between March 2011 and August 2012. Estimated average daily intake (EADI) and target hazard quotient (THQ) were used to determine the risk implications for adult and child consumer populations. Range of Cd, Pb, Zn, and Cu across sites was 0.16–0.46, 1.48–3.17, 2.21–3.65, and 9.48–12.76 mg kg^?1 crab flesh wet weight, respectively. Lead concentrations in crab flesh from Makoko (3.16 ± 1.44 mg kg^?1) and Iddo (5.17 ± 1.26 mg kg^?1) exceeded the maximum accepted limits recommended by the Food and Agriculture Organization/World Health Organization for food fisheries. The EADI across sites for the adult consumer population exceeded the reference dose (RfD) recommended by the U.S. Environmental Protection Agency for most metals with magnitude of ≤7-fold while EADI of Pb among child consumer population across sites exceeded RfD by a maximum of 4.5-fold. THQs for adult population were >1 for all metals across all sites, and >1 for Pb and Cd for selected sites for the child consumer population. Findings from this study indicate higher health risks of metal toxicity to adult consumer populations, and risks of lead toxicity to child consumer populations around the Lagos Lagoon, Nigeria.     

经济甲壳动物实验种群的研究进展

综述了近１０年来国内外经济甲壳动物实验种群的研究进展。内容包括几种主要经济种类的生活环境条件,如水温、盐度、溶氧量、透明度、底质等;饵料方面的研究;种内关系（性别、种内竞争）;种间关系（种间竞争、捕食、混养）;甲壳动物的特征行为—自截对其自身的影响以及病害等方面的研究结果。     

A new Lower Cretaceous bird from China and tooth reduction in early avian evolution

A new avian genus and species, Zhongjianornis yangi gen. et sp. nov., is reported from the Lower Cretaceous lacustrine deposits of the Jiufotang Formation in Liaoning, northeast China. The new taxon is characterized by possessing the following combination of features: upper and lower jaws toothless, snout pointed, humerus with large and robust deltopectoral crest, second phalanx of the major manual digit longer than the first phalanx, unguals of the alular and major digits of similar length and significantly shorter than the corresponding penultimate phalanges, tibiotarsus slender and more than twice the length of the tarsometatarsus, and metatarsal IV longer than the other metatarsals. Phylogenetic analysis indicates that Zhongjianornis is phylogenetically basal to Confuciusornis and the dominant Mesozoic avian groups, Enantiornithes and Ornithurae, and therefore provides significant new information regarding the diversification of birds in the Early Cretaceous. It also represents the most basal bird that completely lacks teeth, suggesting that tooth loss was more common than expected in early avian evolution and that the avian beak appeared independently in several avian lineages, most probably as a response to selective pressure for weight reduction. Finally, the presence of a significantly enlarged humeral deltopectoral crest suggests that Zhongjianornis shares with other basal birds such as Jeholornis, Sapeornis and Confuciusornis a distinctive mode of adaptation for flight contrasting with that seen in more advanced birds, which instead possess an elongated sternum and a prominent keel.     

THE EFFECTS OF TEMPERATURE ON SEXUAL DIFFERENTIATION IN THE TEMPERATURE SENSITIVE THELYGENIC—INTERSEXUAL OFFSPRING OF ORCHESTIA GAMMARELLUS (PALLAS) (AMPHIPODA; CRUSTACEA)

Some females of Orchestia gammarellus generate offspring which include too many females as well as intersexual males. This thelygeny related to intersexuality is temperature sensitive; it disappears above 22°C. It is induced by a feminising parasite described in another work. We have studied how the temperature acts on pubescent thelygenic females having either a known or unknown genotype (♀ 2AYY). The increase of female breeding temperature up to 25 or 30°C has two kinds of consequences for their offspring: (i) an increase in the male ratio, that is to say the expression of the normal genetic sex in potential neo females, and (ii) a correlative decrease in the proportion of intersexual males. The strength of these effects varies according to several parameters: temperature, exposure duration and genotype of tested females.     

The Effect of the Mesoparasitic Barnacle Anelasma on the Development of Reproductive Organs of Deep-sea Squaloid Sharks, Centroscyllium and Etmopterus

Specimens of the mesoparasitic barnacle, Anelasma, were found attached to several host deep-sea squaloid sharks, Centroscyllium fabricii from off Greenland, Etmopterus princeps from the Canary Islands, and Etmopterus unicolor and Etmopterus granulosus from Three Kings Ridge and Louisville Ridge near New Zealand. One to three parasites were partially embedded in each host shark in the head, mouth, bases of 1st and 2nd dorsal fins, pectoral and pelvic fins, caudal fin, abdomen or claspers. Testes and claspers of parasitized mature-sized males were less developed than those of non-parasitized mature males. The ova of parasitized females of mature size were small and whitish-yellow compared to the large yellow ova of non-parasitized mature females. The number of mature ova in a parasitized specimen was lower than expected in relation to a non-parasitized individual of the same size. Attachment of parasitic barnacles appeared to retard the development of reproductive organs of host sharks.     

The gastric mill of euphausiid crustaceans: a comparison of eleven species

The morphology of the gastric mill of 11 species in the family Euphausiidae is described. Two distinct arrangements can be recognized with respect to presence or absence of lateral teeth. One is the well-developed gastric mill of Thsanoessa gregaria, T. inermis, T. macrura and Pseudeuphausia sinica; the other is the gastric mill without lateral teeth of Nematoscelis atlantica, N. difficilis, N. megalops, Nematobrachion flexipes, N. sexspinosum, Stylocheiron abbreviatum, and S. carinatum. This supports the close relationships of the four species of both genera, Thysanoessa and Pseudeuphausia on the one hand and seven species belonging to Nematobrachion, Nematoscelis, and Stylocheiron on the other hand. The hypothesis that species in the same genus have similar gastric mill morphology, which was once rejected in the genus Thysanopoda, is accepted in all five genera examined here. Functional morphology of euphausiid foreguts is discussed.     

The importance of juveniles in structuring a littoral macrobenthic community

The relationships between individual dry weight and bodycontent of the essential metals copper and zinc and of therespiratory pigment haemocyanin have been investigated in fourBritish species of caridean decapod crustaceans, Palaemonelegans, Palaemon longirostris, Palaemonetesvarians and Crangon crangon. Also considered were thebody concentrations of soluble copper and copper associatedwith haemocyanin. These decapods regulate total bodyconcentrations of copper and zinc to approximately constantlevels which can vary interspecifically. An attempt is made tointerpret these regulated concentrations in terms of essentialrequirements for the metals in the physiological functioningof haemocyanin, the body concentration of which variesinterspecifically and intraspecifically with environmentalvariables.     

Osmoregulation in Corophium curvispinum (Crustacea: Amphipoda), a recent coloniser of freshwater

Summary Sodium efflux in three populations of the freshwater amphipod Corophium curvispinum were measured seasonally over a 6-year period and compared to rates recorded in 1980. While continuing to show relatively high Na⁺ loss rates, compared to other freshwater amphipod species, sodium permeability (P_Na) has decreased significantly in the medium term (post 1983). P_Na also shows seasonal fluctuations in all populations. Changes in body sodium content (B^Na) and blood [Na⁺] were found during this period and some alteration of the kinetic characteristics, K_m and V_max, of the sodium uptake system has occurred. Acclimation to different [Na⁺] media, and to low and high temperatures produced significant changes in Na⁺ efflux. The importance of acclimation (acclimatization) and selection in reducing passive Na⁺ loss and effecting changes in Na⁺ regulation of this colonizing species are assessed in relation to environmental changes.     

一叶萩大孢子发生和雌配子体发育

采用石蜡切片法对一叶萩(Flueggea suffruticosa(Pall.) Baill.)雌花大孢子发生及雌配子体的发育过程进行了观察。结果表明：一叶萩子房上位;中轴胎座;三室;每室2枚倒生胚珠;双珠被;厚珠心;具大戟科常见的珠心喙和珠孔塞。胚囊发育为蓼型;成熟胚囊结构为：卵器位于珠孔端;包括2个助细胞和1个卵细胞;中央是1个二核的中央细胞;合点端为3个反足细胞。本研究为大戟科植物生殖生物学和传粉生物学研究提供了基础资料;同时对大戟科植物系统分类研究有一定意义。