Immediate Effects of Experimental Human Trampling on Mid-Upper Intertidal benthic Invertebrates at the Asinara Island MPA (NW Mediterranean)

To assess potential risks of human visitation to ecological communities, the immediate effects of human trampling were investigated experimentally on small invertebrates inhabiting mid-upper intertidal hard bottoms covered by algae. Two different experimental intensities of trampling (60 and 120 footsteps) and controls (with no trampling) were applied to quadrats 20×20 cm in size (experimental area), within the two ‘no-entry, no-take’ zones of the Asinara Island MPA (Italy, Mediterranean Sea). One day after trampling ended, samples of benthic fauna were collected and the animals attributed to macrofaunal and meiofaunal components. Analyses of variance on the nine most common taxa of macrofauna identified significant higher abundance of bivalves, gammarid amphipods, polychaetes, isopods, oligochaetes in controls than in trampled plots. For nematodes, polychaetes, ostracods, oligochaetes, bivalves, acari, caprellid amphipods and tanaids a significant higher abundance of meiofaunal animals was found in controls than in trampled areas. Although no information on recovery is available, these results suggest that macrofaunal and meiofaunal taxa are vulnerable to this type of disturbance.     

Postcopulatory fertilization bias as a form of cryptic sexual selection

Males and females share most of their genetic material yet often experience very different selection pressures. Some traits that are adaptive when expressed in males may therefore be maladaptive when expressed in females. Recent studies demonstrating negative correlations in fitness between parents and their opposite-sex progeny suggest that natural selection may favor a reduction in trait correlations between the sexes to partially mitigate intralocus sexual conflict. We studied sex-specific forms of selection acting in Anolis lizards in the Greater Antilles, a group for which the importance of natural selection has been well documented in species-level diversification, but for which less is known about sexual selection. Using the brown anole (Anolis sagrei), we measured fitness-related variation in morphology (body size), and variation in two traits reflecting whole animal physiological condition: running endurance and immune function. Correlations between body size and physiological traits were opposite between males and females and the form of natural selection acting on physiological traits significantly differed between the sexes. Moreover, physiological traits in progeny were correlated with the body-size of their sires, but correlations were null or even negative between parents and their opposite-sex progeny. Although results based on phenotypic and genetic correlations, as well as the action of natural selection, suggest the potential for intralocus sexual conflict, females used sire body size as a cue to sort sperm for the production of either sons or daughters. Our results suggest that intralocus sexual conflict may be at least partly resolved through post-copulatory sperm choice in A. sagrei.     

Occurrence and removal of parasites, enteric bacteria and faecal contamination indicators in wastewater natural reclamation systems in Tenerife-Canary Islands, Spain

Two wastewater natural reclamation systems (WWNRS) have been compared regarding their efficiencies on faecal bacteria removal and the persistence of enteric pathogens. These WWNRS are constituted of a combination of anaerobic treatment, small sub-surface flow constructed wetland refilled of volcanic ashes and a final pond as water reservoir. Faecal coliforms, enterococci, Escherichia coli, Clostridium perfringens, somatic coliphages, Salmonella sp., Campylobacter sp., Cryptosporidium sp., Giardia sp. and helminth eggs were analyzed in constructed wetlands inlet and outlet and storage pond effluent. Low numbers of protozoan positive samples (4.54% in Albergue de Bolico for both protozoa, and 19.05% in Carrizal Alto for Giardia sp.) and absence of helminth eggs were found. Both systems demonstrated efficient reduction of faecal contamination indicators in the wastewaters (removal rates values of 2 log₁₀). The natural systems for wastewater treatment used to be efficient in Salmonella abatement, this fact was confirmed in the reported systems, since enterobacteriaceae were found in only one of the effluents. Campylobacter species associated with the access of animals to storage ponds were detected in the reclaimed water.     

Impacts of dust on plant health,survivorship and plant communities in semi‐arid environments

There is a general perception that dust accumulation on plant surfaces causes negative impacts to plants. Consequently, it is common for environmental regulatory agencies to apply vegetation monitoring requirements to oil, gas and mining developments. We use two independent, medium‐term monitoring studies in semi‐arid Australia to examine this relationship at two scales: plant health and survivorship of a threatened subspecies (Tetratheca paynterae paynterae: Elaeocarpaceae) at Windarling Range between 2003 and 2014; and changes in plant health and floristic composition on Barrow Island between 2009 and 2014. Accumulation of dust decreased rapidly with distance from source. At Windarling Range, even at the site with the highest dust load, there was no significant impact on Tetratheca paynterae paynterae compared with the less dusty sites for 10 years. Similarly, there was no significant effect between distance from the source of dust and floristic composition on Barrow Island for 5 years. The probability of plants transitioning to a lower health condition between one year and the next did not appear to be related to dust load. This is further supported by comparing the same site before and after paving the road (removal of dust source), which showed no clear trends. Trends in plant health are likely to be driven more by the variability of cumulative rainfall in the preceding 5 months than dust load. The observed temporal variation in the mean dust load may also be related to variation in rainfall. In conclusion, in these case studies from semi‐arid Australia, we find no evidence to support the perception that, under the observed climatic condition and dust deposition rates up to 20 or 77 g m^?2 per month at Windarling Range and Barrow Island, respectively, dust accumulation on plants causes negative impacts.     

Feral cat diet and impact on sooty terns at Juan de Nova Island, Mozambique Channel

Feral cat Felis catus predation on seabirds has been well documented; however, details regarding shifts in feral cat diet in relation to seabird availability, seabird predation rate and impact on seabird population dynamics are scarce. Here, we present data documenting a seasonal shift in feral cat diet at Juan de Nova Island, Mozambique Channel. We also quantify sooty tern Sterna fuscata predation by feral cats and examine the impact on sooty terns over both the short term (by removing individual cats from sub-colonies) and over the longer term by highlighting their influence on population growth rate ( λ ) using a deterministic matrix model. Cat diet shifted dramatically from insects, rats and mice outside the tern breeding season to primarily terns when terns were breeding. The predation rate of sooty terns at Juan de Nova was estimated at 5.94 terns cat⁻¹ day⁻¹, with a proportion of these (22%) being killed without being consumed ('surplus kills'). When only one cat was removed from each sub-colony, tern predation declined tenfold in the short term. From our matrix model, the annual growth rate for sooty terns was 1.01 in the absence of cat predation. It remained above one until a predation impact equivalent to approximately three times the estimated cat density (12.04 per km²) was incorporated. Our results demonstrate that cats preferentially predate and have an impact on breeding sooty terns at Juan de Nova, and that an increase in cat density could lead to negative effects on population growth, despite the large breeding tern population.     

Dissolved organic carbon concentration of a natural water body and its relationship to water color in Central Kalimantan, Indonesia

In Central Kalimantan, Indonesia, the water of lakes and rivers showed high dissolved organic carbon (DOC) concentration, 5-50mgC/l. There was a clear relationship between DOC concentration and pH. DOC also contributed to low water transparency in the studied lakes. Water colors measured by spectrophotometer showed a strong relationship with DOC concentration, indicating high applicability of water color measurement for estimation of DOC. The development of a simple but quick estimation of DOC will contribute to understanding the seasonal dynamics of DOC, which might regulate both abiotic and biotic conditions in aquatic ecosystems in this area.     

海南岛翼手目物种多样性现状与分布预测

海南岛位于我国南部, 地处热带北缘, 其独特的岛屿气候环境孕育了丰富的生物资源, 为我国生物多样性热点地区之一。为探究岛内的翼手目物种多样性状况, 本研究组使用雾网、蝙蝠竖琴网等工具, 于2002年至2016年先后对海南岛进行了15次翼手目多样性调查, 并根据其外形与头骨特征及系统发育学方法进行标本鉴定。共获取了1,025号标本, 隶属5科15属31种, 其中2016年12月21日在海南琼中捕获的艾氏管鼻蝠(Murina eleryi)为海南岛蝙蝠分布新记录。结合前人调查及发表结果统计, 岛内共有翼手类8科20属41种。同时基于本调查采集位点和前人调查位置信息(共计363个位点), 结合WorldClim 32种气候数据, 运用最大熵模型(MaxEnt)对海南岛翼手目物种的分布进行预测, 结果显示五指山、吊罗山、鹦哥岭、尖峰岭及海口火山口国家地质公园等地为翼手目物种多样性较丰富的区域, 而三亚、澄迈、屯昌、临高、琼海等地翼手目物种多样性较低。本研究结果为海南岛翼手目资源分布及多样性状况提供了基础资料, 也为岛内后续开展翼手目资源保护管理、蝙蝠疾病防控等提供了重要的参考依据。     

Ecological speciation in sympatric palms: 1. Gene expression,selection and pleiotropy

Ecological speciation requires divergent selection, reproductive isolation and a genetic mechanism to link the two. We examined the role of gene expression and coding sequence evolution in this process using two species of Howea palms that have diverged sympatrically on Lord Howe Island, Australia. These palms are associated with distinct soil types and have displaced flowering times, representing an ideal candidate for ecological speciation. We generated large amounts of RNA‐Seq data from multiple individuals and tissue types collected on the island from each of the two species. We found that differentially expressed loci as well as those with divergent coding sequences between Howea species were associated with known ecological and phenotypic differences, including response to salinity, drought, pH and flowering time. From these loci, we identified potential ‘ecological speciation genes’ and further validate their effect on flowering time by knocking out orthologous loci in a model plant species. Finally, we put forward six plausible ecological speciation loci, providing support for the hypothesis that pleiotropy could help to overcome the antagonism between selection and recombination during speciation with gene flow.     

基于亲权鉴定的千岛湖社鼠家群遗传结构与亲缘关系特征研究

于2009年7月至2010年11月,对浙江千岛湖两个岛屿上的社鼠(Niviventer confucianus)种群进行标志重捕,并采用8个高多态性的微卫星位点,对两个岛屿的社鼠种群进行家群分析和亲权鉴定,探讨了社鼠家群的亲缘关系特征。结果显示,8个微卫星位点能可靠地对两个岛屿社鼠种群进行亲权鉴定,A岛已确定亲缘关系的71只社鼠分为12个家群,家群中的个体数最多达到19个,B岛已确定的49只社鼠个体共分为11个家群,家群中的个体数最多达到14个。家群内部成员之间的亲缘关系表现为配对繁殖的个体对间亲缘系数最小,揭示了社鼠倾向于选择亲缘关系较远的异性作为配偶。家群中雄性后代个体之间与雌性个体之间的亲缘关系相比,两岛表现情况相反,该结果暗示两岛屿上社鼠扩散行为可能有所不同。通过计算与同一雄性(或同一雌性)交配的个体间的亲缘系数,发现两个岛屿上的社鼠在与不同异性交配时也存在选择性,即避免选择亲缘关系较近的异性作为混交的对象。     

REPORT OF A NEW INVASIVE ALGA IN THE ATLANTIC UNITED STATES: “HETEROSIPHONIA” JAPONICA IN RHODE ISLAND1

Recent collections of tetrasporangiate “Heterosiphonia” japonica Yendo from Watch Hill to Point Judith, Rhode Island, represent the first report of this nonnative alga in the western Atlantic. Native to the Pacific Ocean, this species was unintentionally introduced into European waters by 1984 and has subsequently invaded the eastern Atlantic Ocean widely from France to Norway and south into the Mediterranean Sea. Thus far, all western Atlantic collections of this species are confined to the outer coast of Rhode Island, and at present are not found in Narragansett Bay or in Long Island Sound along the Connecticut coast. Molecular and morphological studies confirm the identity of this newly introduced invasive species.