The plankton community of Lake Matano: factors regulating plankton composition and relative abundance in an ancient,tropical lake of Indonesia

Recent evidence reveals that food webs within the Malili Lakes, Sulawesi, Indonesia, support community assemblages that are made up primarily of endemic species. It has been suggested that many of the species radiations, as well as the paucity of cosmopolitan species in the lakes, are related to resource limitation. In order to substantiate the possibility that resource limitation is playing such an important role, a study of the phytoplankton and zooplankton communities of Lake Matano was implemented between 2000 and 2004. We determined species diversity, relative abundances, size ranges, and total biomass for the phytoplankton and zooplankton, including the distribution of ovigerous individuals throughout the epilimnion of Lake Matano in three field seasons. The phytoplankton community exhibited very low biomass (<15 μg l^?1) and species richness was depressed. The zooplankton assemblage was also limited in biomass (2.5 mg l^?1) and consisted only of three taxa including the endemic calanoid Eodiaptomus wolterecki var. matanensis, the endemic cyclopoid, Tropocyclops matanensis and the rotifer Horaella brehmi. Zooplankton were very small (<600 μm body length), and spatial habitat partitioning was observed, with Tropocylops being confined to below 80 m, while rotifer and calanoid species were consistently observed above 80 m. Less than 0.1% of the calanoid copepods in each year were egg-bearing, suggesting very low population turnover rates. It was concluded that chemical factors as opposed to physical or biological processes were regulating the observed very low standing crops of phytoplankton which in turn supports a very minimal zooplankton community restricted in both species composition and abundance. As chemical factors are a function of the catchment basin of Lake Matano, it is predicted that resource limitation has long played an important role in shaping the unique endemic assemblages currently observed in the food web of the lake.     

Strong population genetic structure and its implications for the conservation and management of the endangered Itasenpara bitterling

To infer the population genetic structure and genetic diversity of Itasenpara bitterling (Acheilognathus longipinnis), a cyprinid species endemic to Japan and distributed in only three specific regions, we investigated mitochondrial DNA variation. The distribution of the haplotypes among the three regions showed distinct geographic structure, and no common haplotypes were observed among regions. Analysis of molecular variance revealed a significant proportion of the genetic variance was partitioned among regions (93.1 %, P < 0.001), and pairwise estimates of D_A and Φ_ST between regions also revealed strong population structure. Given the strong genetic structure and low genetic diversity within regions, we strongly suggest that each region should be treated as a separate unit in any conservation program and any inter-regional translocations should be avoided.     

Allozyme diversity levels in two congeneric Dioon spp. (Zamiaceae, Cycadales) with contrasting rarities

Allozyme diversity and population genetic structure studies were conducted in populations of two Mexican cycad species occurring in adjacent and closely related biogeographic regions. We evaluated if rarity traits in Dioon caputoi, a micro-endemic species, and Dioon merolae, a regional endemic with a wider distribution, influence levels of genetic diversity in different ways. We also explored if genetic structure differs in these species, considering that they have similar population histories. Our results indicate that D. caputoi harbors lower levels of genetic diversity and allelic richness (H _E = 0.358, P = 76.9, A _r = 1.86) than D. merolae (H _E = 0.446, P = 92.3, A _r = 2). However, genetic structure does not differ between the two species despite their contrasting geographic distributions (F _ST = 0.06 vs. 0.07; D. caputoi and D. merolae, respectively). The comparison of population genetic structure information with historical and geographical aspects of the populations suggests that the rarity of D. caputoi might be due to relatively recent local ecological factors.     

Rediscovery of ‘lost’ treefrogs from the Oaxacan highlands of Mexico

The Oaxacan highlands of Mexico boast an exceptional diversity of stream-breeding treefrogs (Hylidae). Recent surveys in these regions have reported dramatic declines for entire stream-breeding communities, and many endemic species have not been seen in several decades and are feared to be extinct. In 2007 we conducted a rapid survey in two focal regions that were surveyed in 1970 and 2000; both prior to and subsequent to reported population declines. We report on extant populations of six species missing from recent surveys following declines, one of which (Plectrohyla thorectes) had not been seen in over 28 years and was feared to be extinct. We document new populations of Exerodonta abdivita, a species previously known only from its type locality and currently listed as data deficient. We make comparisons with historical records and note changes in species composition and abundance with recent work. Differences in species compositions among studies may reflect population declines and rebounds over relatively short periods. However, we argue that aspects of species natural history in combination with the variable nature of brief surveys may account for some of the observed differences, and are important factors to consider when inferring species declines.     

Evolutionary genetics of the endemic Schizorathicine (Cypriniformes: Cyprinidae) fishes of Lake Rara,Nepal

The three endemic species of Schizothorax from Lake Rara, Nepal comprise a putative cyprinid species flock. Mitochondrial DNA sequences were compared for specimens of the endemic species S. raraensis, S. macrophthalmus, and S. nepalensis, and specimens of S. richardsonii and S. progastus from the Karnali River, Koshi River, and Kali Gandaki River drainages. An analysis of molecular variance demonstrated that S. nepalensis is genetically distinct from a group composed of S. raraensis and S. macrophthalmus. Phylogenetic analyses based on parsimony failed to corroborate or conclusively reject a hypothesis of monophyly for the three endemic species of Schizothorax from Lake Rara. The mtDNA haplotypes of S. richardsonii and S. progastus from the Karnali River drainage were not significantly differentiated from one another, but pairwise comparisons of haplotypes from the Lake Rara basin, Karnali River drainage, Koshi River drainage, and Kali Gandaki River drainage were significantly differentiated from one another.     

Abundance,distribution, and territory areas of rock-dwelling Lake Tanganyika cichlid fish species

Lake Tanganyika, the second-oldest and second-deepest lake in the world, harbors an impressive cichlid fish fauna counting about 250 endemic species that are characterized by a great level of ecological, morphological, and behavioral specialization. This study describes and compares cichlid fish communities at two rocky shores with differential human impact in the south of Lake Tanganyika. Species inventories and depth-dependent abundances were elaborated. About 41 and 46 sympatric cichlid species were recorded in the two study sites, respectively. Variabilichromis moorii was the most abundant species (29–60% of total number of fishes), followed by Aulonocranus dewindti (3–19%), Tropheus moorii (12%), Ophthalmotilapia ventralis (4–10%), Eretmodus cyanostictus (6–11%), and Cyathopharynx furcifer (0.01–9%). All other species had abundances below 5%. It further emerged that large cichlids such as Petrochromis species, Cyathopharynx furcifer, and Lobochilotes labiatus were very rare at one location, with frequencies of 0.55% or less. Territorial sizes of three particularly abundant species, Variabilichromis moorii, Aulonocranus dewindti, and Tropheus moorii, were assessed by behavioral observations. We distinguished between territorial core areas and total defended area, yielding average core areas between 0.4 (V. moorii) and 1.6 m² (T. moorii), and total defended areas averaging for each species between 1.6 (V. moorii) and 5.0 m² (A. dewindti) with no significant differences between the two study sites. The data on individual densities are also relevant for evolutionary studies, in that they allow more accurate calculations of effective population sizes.     

Invasion dynamics of the snail Pseudoplotia scabra in Lake Kinneret

The freshwater snail Pseudoplotia scabra Müller (Thiaridae) was first spotted in Lake Kinneret, Israel, in the mid 2000s. In a series of field surveys we followed its spread, documenting how by the end of 2010 this invasive mollusc formed >95 % of the snails in Lake Kinneret, nearly eradicating four native species.     

Environmental Regulation of Mitochondria-Rich Cells in Chalcalburnus tarichi (Pallas, 1811) During Reproductive Migration

Chalcalburnus tarichi is an anadromous cyprinid fish that has adapted to extreme conditions (salinity 22 ‰, pH 9.8 and alkalinity 153 mEq × l^?1) in Lake Van in eastern Turkey. Changes in immunoreactivity of Na⁺/K⁺-ATPase in gill tissue and osmolarity and ion levels in plasma were investigated in C. tarichi during reproductive migration. Physicochemical characteristics and ion levels in Lake Van were high compared freshwater. Plasma osmolality and plasma ion concentrations ([Na⁺], [K⁺] and [Cl^?]) increased after transfer from freshwater to Lake Van. The mitochondria-rich (MR) cells of the gill were stained in both filament and lamellar epithelia of C. tarichi by immunocytochemistry with a specific antiserum for Na⁺/K⁺-ATPase in river fish samples. Density and area of MR cells were decreased in lake-adapted fishes. These results indicated that freshwater acclimation capacity is correlated with the size and distribution of MR cells in C. tarichi, in contrast to many teleost fishes.     

Alien and native tree species having extrafloral nectaries as favorite hunting area for arboreal endemic Philippine tiger beetles (Coleoptera: Cicindelidae) in human‐disturbed habitat in Lanao del Sur Province,Mindanao, Philippines

To document a relation between abundance of arboreal, predatory tiger beetles, their ant prey, and extrafloral nectaries attracting the ants, we gathered data from more than 10 species of native and introduced trees and large, tree‐like perennial plants in Lanao del Sur Province, Mindanao, Philippines. All specimens of tiger beetles (two Tricondyla and two Neocollyris species, all endemic to the country) were noted on five tree species characterized by presence of extrafloral nectaries, including three alien/invasive and two native ones. Invasive Spathodea campanulata and native Hibiscus tiliaceus were the most inhabited ones (respectively, 56% and 19% of beetles). Presence of tiger beetles on these trees most probably depends on high abundance of ants, which are typical prey for arboreal Cicindelidae, while occurrence of ants can result from presence of extrafloral nectaries on different parts of the plants. This suggests a new mutualistic insect–plant interaction between native and invasive species.     

Microsatellite markers from a commercially important South‐east Asian cyprinid,the silver barb (Barbodes gonionotus Bleeker)

Barbodes gonionotus (Puntius gonionotus/javanicus, Bleeker) is a cyprinid fish, endemic to South‐east Asia and is of great importance in both wild fisheries and in aquaculture in the region. It is a common to dominant species in the middle and lower stretches of medium and large rivers. Five highly polymorphic microsatellite loci are described (H_O = 0.7–0.9, number of alleles per locus = 10–37), which will be of use both in population genetic studies and for the assessment of true effective breeding population sizes in aquaculture stocks.     

Temporal changes in the breeding bird community caused by post-fire treatments after the Samcheok forest fire in Korea

The Samcheok forest fire of April 2000 was the biggest stand-replacing fire recorded in Korea, and led to the largest-scale salvage logging operation (performed until 2005) ever implemented. We investigated the effects of the treatments performed after the fire on the breeding bird community in 2002–2005 (the management period) and 2006–2008 (the post-management period). A total of 75 line transect surveys resulted in 660 detections of 54 species in undisturbed stands (CO), in burned and naturally restored stands (NI), and in burned and logged stands (IT). Four species (Parus major, Aegithalos caudatus, Dendrocopos kizuki, and Parus ater) were identified as indicator species in CO which showed no temporal changes in bird communities and habitat structure. Among the various stand treatments, the standardized species richness was highest in CO (11.6 ± 4.6 species/transect in 2002–2005, 12.1 ± 3.5 in 2006–2008), and this richness did not change over time. On the other hand, low richness was observed in NI (6.8 ± 2.6 in 2002–2005, 9.6 ± 2.3 in 2006–2008), and the lowest richness was seen in IT (5.0 ± 2.4 in 2002–2005, 6.1 ± 1.8 in 2006–2008), but both of these increased over time. Although the bird abundances in NI and IT were lower than those in CO (38.0 ± 27.7 birds/transect in 2002–2005, 31.3 ± 10.9 in 2006–2008), the abundances in NI (15.1 ± 8.6 in 2002–2005, 17.6 ± 11.4 in 2006–2008) and IT (11.7 ± 8.3 in 2002–2005, 10.0 ± 4.6 in 2006–2008) were not significantly different. There was no significant difference in abundance between time periods for any of the stand treatments. These results imply that NI (i.e., no salvage logging) allows greater bird richness but not abundance to be recovered compared to IT. No indicator species was consistently present in NI throughout the two time periods covered due to the rapid regrowth of vegetation, but four open-habitat dwellers (Falco tinnunculus, Phoenicurus auroreus, Emberiza cioides, and Sturnus cineraceus) colonized IT during the post-management period. The bird assemblage in IT, as assessed by canonical correspondence analysis, shifted to open habitats, while the avifauna in NI became similar to that in CO over time. While post-fire treatment can provide new colonization opportunities for open-habitat dwellers, the slow colonization process, the low species richness, and the low bird abundance observed in large areas of IT indicate that post-fire treatment using salvage logging inhibits the restoration of forest bird communities by producing a poorer breeding bird community that is very different from the original one. Based on these lessons from the response to the Samcheok forest fire, we suggest that preserving as much of the disturbed forest as possible is essential, and that the current approach to post-fire treatment—intensive salvage logging—needs to be revised to ensure the effective restoration of breeding bird communities in disturbed temperate pine forests.     

Insights into the biodiversity of the Succulent Karoo hotspot of South Africa: the population genetics of a rare and endemic halictid bee,Patellapis doleritica

Population genetic analyses are especially relevant for species considered threatened or highly endemic and for which other forms of biological information are lacking. Patellapis doleritica is a recently described communally nesting halictid bee of conservation concern because it is rare and endemic to the Succulent Karoo of South Africa. Moreover, its dispersal is considered to be restricted by its specialised nesting requirements and inclement weather conditions during its limited annual flight period, traits which may be common to other bee species of the region. We hypothesised that gene flow in P. doleritica was low, leading to marked genetic differentiation. Using 7 microsatellites, we investigated its mating and population genetic structure in 258 individuals (171 females and 87 males) from 7 populations spanning most of its known range. Deviation from Hardy–Weinberg equilibrium (F_IS = + 0.254) suggested P. doleritica to be inbred, as in many other communal nesting bee species. Global F_ST (0.028) and global G′_ST (0.216) revealed modest but significant differentiation between most populations, even across the very limited range of the species (ca. 25 km), with one genetically extreme outlier population. Despite inbreeding, we detected a surprisingly low frequency of diploid males (2 %). Patellapis doleritica nevertheless deserves special conservation attention since it is an endemic species with a low overall abundance and therefore possibly prone to environmental change and local extinction.     

The ‘paradigm of extremes’: extremely low genetic diversity in an extremely narrow endemic species, Coristospermum huteri (Umbelliferae)

Low levels of genetic diversity in endemic species are generally attributable to the small size of their populations. This lack of genetic variability will, predictably, be more evident in those species that occur in only one or a very few localities with a total population consisting of a few dozen individuals, or sometimes fewer (i.e. ‘extremely narrow endemics’, ENEs). We used allozyme electrophoresis to survey the genetic variability of Coristospermum huteri, an endemic species from the island of Majorca (Balearic Islands, W. Mediterranean Basin) with a single natural population of about 100 individuals. As expected, allozyme variability was virtually nil for this species (P = 8.3 %, A = 1.08, H _e = 0.022), which seems to be a general rule for ENEs (mean H _e = 0.057). A founder effect associated with a dispersal event from the continent is probably behind the lack of genetic diversity in this highly threatened species. Preservation of the mountain summit where the plant is found (Puig Major) is essential for the survival of C. huteri, and would also guarantee the conservation of other ENEs and rare and threatened species.     

Recent invasion by a non-native cyprinid (common bream Abramis brama) is followed by major changes in the ecological quality of a shallow lake in southern Europe

We present an example of how an invasion by a non-native cyprinid (common bream, Abramis brama (Pisces: Cyprinidae), hereafter bream) in a natural shallow lake in southern Europe (Lake Montorfano, northern Italy) may have adversely affected the state of the lake’s ecosystem. In less than two decades, bream became the most abundant species and characterized by a stunted population with asymptotic length 33.5 cm, an estimated mean length at first maturity of 19.6 cm, a total mortality rate of 0.64 year^?1 and a diet overwhelmingly dominated by microcrustaceans. Following bream establishment, nutrients and phytoplankton biomass rose, the proportion of Cyanobacteria by numbers increased markedly and water transparency decreased. Total zooplankton abundance increased with a marked increase in small cladocerans and copepods, whereas the abundance of large herbivorous cladocerans did not change. The coverage of submerged macrophytes declined, as did the abundance of native pelagic zooplanktivorous fish. The composition of the fish community shifted towards a higher proportion of zoobenthivorous species, such as bream and pumpkinseed (Lepomis gibbosus). Our results indicate that bream affected water quality through bottom-up mechanisms, while top-down effects were comparatively weak. Selective removal of bream and perhaps stocking of native piscivores might improve the ecological status of the lake.     

The effects of land-use policies on the conservation of Borneo’s endemic Presbytis monkeys

Despite supporting the highest biodiversity on Earth, tropical rainforests are undergoing intensive economic development. In particular, the island of Borneo has lost over 56 % of original lowland forest to resource extraction, fires, and illegal logging. Its rainforests contain 16 primate species, which serve as excellent ‘umbrella’ taxa for conservation initiatives. The genus Presbytis (Colobinae) is well represented across Borneo by four endemic species (P. chrysomelas; P. frontata; P. hosei, and P. rubicunda), but remains relatively understudied. Using ecological niche modelling, I calculated the distributions of the 12 Bornean Presbytis subspecies; evaluated habitat loss between 2000 and 2010, and examined the current land-use policies across remnant distributions. Subspecies experienced a mean 12.7 % (N = 12 sp.) habitat reduction over the 10 year period. 12.5 % of all habitats were allocated for conversion to oil palm and industrial tree plantations, while logging concessions accounted for a mean 26.3 % across distributions. While the current protected area networks encompassed an average 33.4 % of distributions, most PAs are underfunded, degraded and threatened by logging and mining operations. I therefore recommend priority gazetting of unallocated lands to new PAs within the distribution of Presbytis chrysomelas and Presbytis hosei sabana, which have experienced the highest forest loss in the last 10 years (22–50 %) and are critically endangered. Logging concessions appear to be at least as effective in maintaining forest cover as PAs and have the economic advantage for effective management, but may have detrimental effects to monkey populations. I recommend an urgent assessment of the effects of selective logging practices on species’ persistence, and further recommend population surveys to quantify the populations of critically endangered and data deficient subspecies.     

Evaluation of Paracoccidioides brasiliensis Infection by gp 43 Intradermal Test in Rural Settlements in Central-West Brazil

Epidemiological studies of paracoccidioidomycosis have been based on surveys achieved with intradermal tests, and paracoccidioidin is the most common antigen used in most cases. The glycoprotein of 43-kDa (gp43) has been used in intradermal tests. It is the most antigenic component of Paracoccidioides brasiliensis, and it provides greater specificity to evaluate infection for this fungus. In this study, the prevalence of P. brasiliensis infection was estimated with intradermal tests involving gp43 for 695 people in rural Central-West Brazil. The infection rate was 45.8 % (95 % CI = 42.1–49.5), and the average age of those infected was 45.8 ± 18.2 years. The prevalence did not show gender-based differences but increased with age. The results demonstrate the importance of P. brasiliensis infection in rural settlements and the early exposure of children in the region to the fungus. Despite the high antigenicity and specificity of gp43, its usage must be standardized, so that epidemiological surveys will be comparable and more accurately reflect P. brasiliensis infection in endemic areas.     

Feeding habit and food partitioning in a stream fish community of Western Ghats,India

The diet and feeding ecology of 12 cyprinid fishes were studied in the Thalayanai stream of southern India. The diet of Barbodes sarana, Danio aequipinnatus and Rasbora daniconius were specialized in terrestrial and aquatic insects. Hypselobarbus dobsoni and Garra mullya consumed vegetative matter and unicellular algae as their most important dietary component, respectively. Hypselobarbus curmuca and Hypselobarbus dubius specialized in crustaceans and molluscs. Puntius amphibious, Puntius bimaculatus, Puntius dorsalis, Puntius filamentosus and Puntius tambraparniei fed on variety of food resources (aquatic insects, algae and detritus) and their feeding intake varied between wet to dry seasons. Levin’s index of diet breadth showed the broadest diets for P. dorsalis in both seasons, whereas G. mullya had a narrow feeding spectrum in both seasons. Among co-existing species, diet overlaps were substantially low during both wet and dry season. These results suggest that feeding specialization and low diet overlap reduce inter-specific competition, allowing co-existence of these cyprinid fishes in this highly structured stream assemblage.     

Comparative phylogeography of two codistributed endemic cyprinids in southeastern Taiwan

Two cyprinid fishes, Spinibarbus hollandi and Onychostoma alticorpus, are endemic to southeastern Taiwan. This study examined the phylogeography of these two codistributed primary freshwater fishes using mitochondrial DNA cytochrome b sequences (1140 bp) to search for general patterns in the effect of historical changes in southeastern Taiwan. In total, 135 specimens belonging to these two species were collected from five populations. These two codistributed species revealed similar genetic variation patterns. The genetic variation in both species was very low, and the geographical distribution of the genetic variation corresponded neither to the drainage structure nor to the geographical distances between the samples. The results of a statistical dispersal-vicariance analysis suggested that the ancestral populations of these two species were distributed in southern Taiwan before their dispersal. Our study suggests that the initial colonization occurred in the Kaoping River followed by eastern and northward dispersal. Our results also indicate that the Central Range in Taiwan did not act as a barrier to the dispersal of S. hollandi or O. alticorpus.     

Invasion spread of Operophtera brumata in northeastern United States and hybridization with O. bruceata

We used five methods to estimate the rate of spread of the winter moth, Operophtera brumata L., a European Lepidoptera, invading the northeastern USA and occasionally hybridizing with the closely related O. bruceata. These two species utilize the same sex attractant and pheromone traps capture both species. We estimated spread based on the ratio of the two species captured in pheromone-baited traps. Population boundaries were derived from captures in a grid of traps and spread was estimated as 6.6 km/year based on displacement of population boundaries between 2005 and 2008. Radial spread rate was also estimated as 6.9 km/year from the displacement of boundaries using logistic regression of trap captures along a single east–west transect of traps deployed yearly from 2007 to 2011. We also estimated the rate of spread from the expansion of defoliation mapped during aerial surveys. Based on the displacement of defoliation boundaries from 2005 to 2008, spread rate was estimated as 6.0 km/year. Based on the year of first defoliation, spread was estimated as 4.8 km/year and regression of the square-root of the cumulative area/π versus time yielded an estimate of 4.7 km/year. All five estimates were similar, and differences reflect the nuances of the data from which they were derived. We discuss here how the occasional hybridization with O. bruceata may be either retarding or enhancing O. brumata spread.     

A New Species of Rhaponticoides (Asteraceae) from Southern Italy

A new diploid (2n?=?30) species, Rhaponticoides calabrica, is described from Calabria and Basilicata (southern Italy). This species differs from the closely related R. centaurium – an endemic of Apulia and northern Basilicata – by different flower colour (white in the former, purplish in the latter), width of membranous margin of phyllaries (1.8?±?0.4 mm vs 0.8?±?0.3 mm) and pappus length (6.8?±?0.9 mm vs 9.1?±?1.0 mm). The two species are completely allopatric and seem to have also different chromosome numbers.