Life history,distribution and molecular phylogenetics of the Upward-Mouth Spikefish Atrophacanthus japonicus (Teleostei: Tetraodontiformes: Triacanthodidae)

Ninety-six juvenile specimens (37–54 mm standard length; L_S) of the rarely collected Upward-Mouth Spikefish Atrophacanthus japonicus (Triacanthodidae) were obtained from the stomachs of three Yellowfin Tuna Thunnus albacares collected off Guam in the Mariana Islands in the central Pacific Ocean. These specimens extend the range of A. japonicus eastward into Oceania. We review the systematic characters of the monotypic genus Atrophacanthus and present colour photographs of freshly collected specimens. The diet of the juvenile specimens of A. japonicus consisted of thecosome pteropods and foraminiferans. We present a range map of A. japonicus based on all known specimens and show that specimen size is related to whether specimens were collected in the pelagic zone or on the bottom. Our results support that, compared to all other Triacanthodidae, A. japonicus has an unusually extended pelagic larval and juvenile period, up to 54 mm L_S, before settling to the bottom as adults. Lastly, we provide a multilocus phylogeny addressing the phylogenetic placement of Atrophacanthus based on eight of 11 triacanthodid genera and six genetic markers. Our results reveal that Atrophacanthus is the sister group of Macrorhamphosodes and they provide new insights about the evolutionary history of the family.     

Profile of Overweight and Obese People in a Mediterranean Region

Objective: To assess the prevalence of excess weight (obesity and overweight) and the related environmental risk factors in a Mediterranean population. Self‐perception of body weight, attitudes toward weight‐control behaviors, and the associated factors were also examined. Research Methods and Procedures: A cross‐sectional nutritional survey was carried out in the Balearic Islands between 1999 and 2000. A random sample (n = 1200) of the adult population (20 to 60 years old) was interviewed. Dietary questionnaires and a global questionnaire incorporating questions related to sociodemographic and lifestyle variables were utilized. Anthropometric measurements were also obtained. Results: Nearly one‐half of the population of the Balearic Islands is above the normal weight range (BMI > 25). The predictors of overweight and obesity in the Balearic Islands are to be over 40 years old, to be married, to form part of the lowest educational levels, and to have a sedentary lifestyle. A large percentage of excess‐weight individuals tend to underestimate their BMI, are not concerned about their weight status, tend to snack more often, and have never dieted. Discussion: Although the likely causes of the rise in obesity prevalence are difficult to elucidate from this study, we have identified the profile of individuals with excess weight in the Balearic Islands as well as their attitudes toward their body image.     

Levels of endemism are not necessarily biased by the co-presence of species with different range sizes: a case study of Vilenkin and Chikatunov's models

Aim  To illustrate problems in the methods proposed by B. Vilenkin and V. Chikatunov to study levels of endemism and species–area relationships.
Location  The study used data on the distribution of tenebrionid beetles (Coleoptera, Tenebrionidae) on the Aegean Islands (Greece).
Methods  A total of 32 islands and 170 taxa (species and subspecies) were included in this study. Levels of endemism were evaluated both as the proportion of endemic taxa, and according to the methods proposed by Vilenkin and Chikatunov, which are based on the number of non-endemic taxa and various relationships with area. A model of the species–area relationship proposed by these authors was also analysed.
Results  The number of endemic taxa was positively correlated with the number of taxa with different distribution types, but this positive correlation did not influence the estimation of the level of endemism. In fact, the commonly used estimate of endemicity as a percentage was strongly correlated with the endemism values calculated according to the method of Vilenkin and Chikatunov. The usual power function fitted the species–area relationship as well as the most complicated method of Vilenkin and Chikatunov.
Main conclusions  As hypothesized by Vilenkin and Chikatunov, the number of endemic taxa was influenced both by the number of taxa of other biogeographical ranks, and by an island's area. However, explanations for the positive relationship between the number of endemic taxa and taxa of different biogeographical ranks are equivocal. Importantly, this relationship did not necessarily influence the level of endemism, which could be expressed adequately by percentages. The method proposed by Vilenkin and Chikatunov to estimate the species–area relationship cannot be clearly justified on theoretical grounds and is of questionable practical utility.     

Marine, intertidal, freshwater and terrestrial biodiversity of an isolated polar archipelago

Aim We ask how biodiverse is a polar archipelago; how this faunal richness is spread across marine, intertidal, freshwater, terrestrial and parasitic realms; and how fast species are accumulated with increased sampling effort. Location The South Orkney Islands (SOI), Scotia Arc, Southern Ocean. Methods We sampled mega‐ and macro‐benthos at the SOI using scuba in the shallows (0–10 m), a rough bottom otter trawl at 150–250 m and an Agassiz trawl and epibenthic sledge, both at depths of 200, 500, 1000 and 1500 m. We also collated species occurrence at the SOI in each realm from a century of literature and modern databases to investigate patterns in species accumulation, endemism, faunistic affinities and bathymetric ranges in three model taxa. Results Our 11 benthic samples showed that point biodiversity at the SOI is high, yielding 19 classes and 158 species. Nearly a third were new to the area, whilst five species and one genus were new to science. The shallowest samples were richest but had fewest new records of species. Known richness at the SOI is dominated by marine species (1026), of which 821 (83.3%) were benthic. Across all realms, 1224 species (50 classes, 24 phyla) were recorded, of which 43 were intertidal, 64 freshwater, 100 terrestrial, 60 parasitic and 40 birds. Species accumulation curves for model taxa showed new sampling yields about 0.75% per sample of known benthic richness, so by Antarctic standards we know the SOI quite well. Most species are Southern Ocean endemics, but very few occur only at the SOI. Main conclusions This first estimate of faunal biodiversity of a polar locality demonstrates both high richness and high levels of knowledge at the SOI. As suspected but never quantified, the benthos dominates polar biodiversity, at least at the SOI. Marine species there constitute 20% of those recently listed for the entire Southern Ocean, whilst > 60% of terrestrial species are known from Antarctica. The SOI, being one of the better‐studied polar locations, of known age and with a discrete shelf, represent an important source of comparison for biodiversity studies. Our data clearly show that richness and our knowledge of the polar fauna differ across environments.     

Multiple colonizations of a remote oceanic archipelago by one species: how common is long‐distance dispersal?

Aim  It is well established that many groups of plants and animals have undergone long-distance dispersal, but the extent to which this continues beyond initial colonization is largely unknown. To provide further insight into the frequency of gene flow mediated by long-distance dispersal, we investigated the origins of the fern Asplenium hookerianum on the Chatham Islands, and present a review of the contribution of molecular data to elucidating the origins of this archipelago's biota.
Location  Chatham Islands and New Zealand. A. hookerianum is scarce on the Chatham Islands but common in New Zealand, some 800 km to the west.
Methods  We compared chloroplast trnL–trnF DNA sequence data from Chatham Islands' A. hookerianum with extensive phylogeographic data for this genetically variable species in mainland New Zealand.
Results  Our sequencing revealed the presence of two haplotypes in Chatham Islands' A. hookerianum . These haplotypes differed by four mutational events and were each more closely related to haplotypes found in New Zealand than to each other.
Main conclusions  Despite the rarity of A. hookerianum on the Chatham Islands, its populations there appear to derive from at least two long-distance dispersal events from New Zealand, these possibly originating from different areas. We suggest that long-distance transoceanic dispersal, and the gene flow it can mediate, may be more common than is generally appreciated.     

How habitat disturbance benefits geckos: Conservation implications

I here provide some field observations and literature data showing that egg laying site availability could be the main limiting factor for most arboreal gecko population dynamics. Several natural (typhoons, volcanism, sea level variations) or human-mediated habitat modifications (garden openings in forested areas) provide enough habitat disturbances to significantly increase reproductive outputs in island gecko populations. Such observations, however, also apply to continental populations. Our observations suggest that artificial shelter and egg laying site creation could easily allow populations to increase and also supply easier access to arboreal species for ecological or biodiversity studies. Furthermore, our observations also point out that occurrence in man-made habitats and genetic uniformity of most widespread island lizards should not be considered as evidence of their recent introduction through human agency.     

Two new Marina (Leguminosae) from the southern Baja California peninsula, Mexico

Marina victoriae andM. brevis are newly described species from the southern Baja California peninsula, Mexico. The former is a perennial herb locally abundant in the eroded hillsides at the foothills of Sierra de la Victoria, where an oak woodland and a dry tropical forest meet. The latter is an elusive ephemeral inhabiting a narrow strip of land between the mangroves and the desert scrub on an island in the Gulf of California. These two new species belong to the seriesChrysorrhizae, a group native to the Gulf of California basin.     

On the Morphology of Arrowhead Flounders of the Genus Atheresthes in the Pacific Waters of the Northern Kuril Islands and Southeastern Kamchatka

This paper presents the results of studies on the morphology of arrowhead flounders, the Kamchatka flounder Atheresthes evermanni (35 specimens), and the American arrowtooth flounder A. stomias (37 specimens) collected in Pacific waters of the northern Kuril Islands and southeastern Kamchatka in 1998–1999. The morphology of the discussed species is compared with that of arrowtooth flounders from other areas. From this comparison, available information on the sharp increase in the density of the American arrowtooth flounder in the surveyed area (since 1997), and similarities in size compositions of the fish in Kuril and Aleutian waters, a conclusion has been made about the penetration of this species from Aleutian Pacific waters into the area of the northern Kuril Islands and southeastern Kamchatka. This is a result of expansion of the geographical range of this species due to general water warming in the northwestern Pacific during the second half of the 1990s.     

浙南岛屿岩相潮间带石鳖的群落结构

研究了浙南岛屿岩相潮间带石鳖的群落结构。用Shannon-Wiener多样性指数（H′）、Pielous种类均匀度（J）、Margalef种类丰度（d)、Berger-Parker优势度指数（I）4个测定群落种类多样性指标进行数值分析,结果表明,水平变化,H′值为北麂的关帝山最大、七星岛最小,J值为洞头的鸽尾礁最大、七星岛最小,d值为南麂的马祖岙口和北麂的海利相对较大、北麂的筲箕屿最小,I值为七星岛最大、洞头的鸽尾礁最小;垂直变化,潮区由高到低,H′、J和d值呈逐渐增大的趋势,I值中潮区开始则逐渐变小;季节变化,H′、J、d值为春季＞夏季＞秋季＞冬季,I值则相反。用Bray-Curtis群落相似性系数聚类分析,浙南岛屿潮间带石鳖群落可聚为两大类型。温度、潮汐、海岸开敞度、浪击度和空间异质性是影响石鳖群落结构的主要因素。