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.     

Temporal variations in the diet of pearly razorfish Xyrichtys novacula (Osteichthyes: Labridae)

The diet of pearly razorfish Xyrichtys novacula, caught monthly along the shores of the Island of Lampedusa, appeared to be mainly composed of crustaceans, followed by colonial ascidians, molluscs and polychaetes. Among prey, sand dwellers and phanerogam‐associated species were recorded. In winter months, the diet was characterized by a small number of prey items, dominated by colonial ascidians, while in spring and summer a wider prey array was recorded. Dietary indices show that X. novacula do not strictly exploit benthic prey but also pelagic organisms, such as copepods. This feeding behaviour reached its peak in March and October, when the abundance of primary consumers was at its highest after phytoplankton blooms. Furthermore, X. novacula caught prey organisms according to their availability and seasonal patterns during their life cycles, irrespective of fish size.     

Cirripedia of Madeira

We give a list of Cirripedia from Madeira Island and nearby deep water, based on specimens in the collection of the Museu Municipal do Funchal (História Natural) (MMF), records mentioned in the literature, and recent collections. Tesseropora atlantica Newman and Ross, 1976 is recorded from Madeira for the first time. The Megabalanus of Madeira is M. azoricus. There are 20 genera containing 27 species, of which 22 occur in depths less than 200 m. Of these shallow water species, eight are wide-ranging oceanic forms that attach to other organisms or to floating objects, leaving just 13 truly benthic shallow water barnacles. This low diversity is probably a consequence of the distance from the continental coasts and the small area of the available habitat. No endemic species have been found.     

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.     

Parasitic Nematodes in the Chimpanzee Population on Rubondo Island, Tanzania

We identified 3 nematodes not previously reported in chimpanzees (Pan troglodytes) introduced on Rubondo Island, Tanzania: Protospirura muricola, Subulura sp., and Anatrichosoma sp. Vervet monkeys (Cercopithecus aethiops pygerythrus), rodents, and intermediate insect hosts might maintain Protospirura muricola and Subulura sp., and indigenous monkeys on the island might also maintain Anatrichosoma sp. Low prevalence of Subulura sp. and Anatrichosoma sp. suggests that chimpanzees acquired them from ingestion of contaminated food.     

气候与白昼长度变化对苏格兰拉姆岛上野化山羊种群日活动节律的影响

对生活于苏格兰西北部拉姆岛上的野化山羊(Caprahircus)种群在1981、1982和2000年三年中的日活动节律进行了分析研究。详细分析了两个主要气象因素(温度和降水)以及昼长季节变化对该种群动物的日活动节律的影响。研究结果表明,拉姆岛上野化山羊的日取食活动时间百分比随月平均温度上升而显著下降,但卧息活动时间百分比随月平均温度的上升而显著上升,而降水则对二者无显著影响。拉姆岛所在地区的昼长季节性变化明显,每年6、7月白昼时间最长,而12、1月最短。由于受昼长季节变化影响,尽管该山羊种群的日取食活动时间百分比随季节变化而由夏季到冬季增加,但其真正用于取食活动的白昼时间由夏季到冬季反而减少。研究表明,白昼时间长短的季节变化是制约该山羊种群取食活动的一个重要因素,尤其是在食物匮乏而天气寒冷、阴湿的冬季。进而探讨了这种制约作用对其冬季取食量和冬季存活率的影响,以及对种群数量的调节意义。     

Patterns of species richness on very small islands: the plants of the Aegean archipelago

Aim To investigate the species–area relationship (SAR) of plants on very small islands, to examine the effect of other factors on species richness, and to check for a possible Small Island Effect (SIE). Location The study used data on the floral composition of 86 very small islands (all < 0.050 km²) of the Aegean archipelago (Greece). Methods We used standard techniques for linear and nonlinear regression in order to check several models of the SAR, and stepwise multiple regression to check for the effects of factors other than area on species richness (‘habitat diversity’, elevation, and distance from nearest large island), as well as the performance of the Choros model. We also checked for the SAR of certain taxonomic and ecological plant groups that are of special importance in eastern Mediterranean islands, such as halophytes, therophytes, Leguminosae and Gramineae. We used one‐way anova to check for differences in richness between grazed and non‐grazed islands, and we explored possible effects of nesting seabirds on the islands’ flora. Results Area explained a small percentage of total species richness variance in all cases. The linearized power model of the SAR provided the best fit for the total species list and several subgroups of species, while the semi‐log model provided better fits for grazed islands, grasses and therophytes. None of the nonlinear models explained more variance. The slope of the SAR was very high, mainly due to the contribution of non‐grazed islands. No significant SIE could be detected. The Choros model explained more variance than all SARs, although a large amount of variance of species richness still remained unexplained. Elevation was found to be the only important factor, other than area, to influence species richness. Habitat diversity did not seem important, although there were serious methodological problems in properly defining it, especially for plants. Grazing was an important factor influencing the flora of small islands. Grazed islands were richer than non‐grazed, but the response of their species richness to area was particularly low, indicating decreased floral heterogeneity among islands. We did not detect any important effects of the presence of nesting seabird colonies. Main conclusions Species richness on small islands may behave idiosyncratically, but this does not always lead to a typical SIE. Plants of Aegean islets conform to the classical Arrhenius model of the SAR, a result mainly due to the contribution of non‐grazed islands. At the same time, the factors examined explain a small portion of total variance in species richness, indicating the possible contribution of other, non‐standard factors, or even of stochastic effects. The proper definition of habitat diversity as pertaining to the taxon examined in each case is a recurrent problem in such studies. Nevertheless, the combined effect of area and a proxy for environmental heterogeneity is once again superior to area alone in explaining species richness.     

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.     

Skin and hair pigmentation variation in Island Melanesia

Skin and hair pigmentation are two of the most easily visible examples of human phenotypic variation. Selection-based explanations for pigmentation variation in humans have focused on the relationship between melanin and ultraviolet radiation, which is largely dependent on latitude. In this study, skin and hair pigmentation were measured as the melanin (M) index, using narrow-band reflectance spectroscopy for 1,135 individuals from Island Melanesia. Overall, the results show remarkable pigmentation variation, given the small geographic region surveyed. This variation is discussed in terms of differences between males and females, among islands, and among neighborhoods within those islands. The relationship of pigmentation to age, latitude, and longitude is also examined. We found that male skin pigmentation was significantly darker than females in 5 of 6 islands examined. Hair pigmentation showed a negative, but weak, correlation with age, while skin pigmentation showed a positive, but also weak, correlation with age. Skin and hair pigmentation varied significantly between islands as well as between neighborhoods within those islands. Bougainvilleans showed significantly darker skin than individuals from any other island considered, and are darker than a previously described African-American population. These findings are discussed in relation to prevailing hypotheses about the role of natural selection in shaping pigmentation variation in the human species, as well as the role of demographic processes such as admixture and drift in Island Melanesia.     

Development of microsatellite markers in heterostylous Hedyotis chrysotricha (Rubiaceae)

? Premise of the study: Microsatellite primers were developed for a heterostylous herb, Hedyotis chrysotricha to investigate the effect of habitat fragmentation on its genetic diversity and population structure. ? Methods and Results: Twelve primer sets were developed and their polymorphisms were tested on 47 individuals from two island populations of H. chrysotricha in Thousand Island Lake of China. The number of alleles per locus ranged from five to 10, with an average of seven alleles. Expected heterozygosity per locus ranged from 0.284 to 0.821 and observed heterozygosity ranged from 0.191 to 0.851. ? Conclusions: We showed that all of the 12 microsatellite markers developed for H. chrysotricha are polymorphic within populations, which should provide a powerful tool for assessing population structure and genetic diversity across fragmented and continuous populations, and for studying the genetic effects of habitat fragmentation on this species.