Comparative larval ontogeny of two fish species (Characiformes and Siluriformes) endemic to the São Francisco River in Brazil

The aim of the present study was to perform comparative histological analyses of the ontogenetic development of two fish species endemic to the São Francisco River in Brazil: Prochilodus argenteus and Lophiosilurus alexandri. Histological analyses were performed every 24 h from the moment of hatching until 14 days post-hatching (dph) for the observation of larval development and until 39 dph for the observation of gonadal development. Whole larvae were fixed in Bouin's solution and the histological slides were stained with haematoxylin–eosin. Lophiosilurus alexandri larvae had a larger body size compared with P. argenteus larvae since hatching. Lophiosilurus alexandri larvae had mouth opening and pigmentation of the eyes upon hatching, whereas these events were observed at 1 dph in P. argenteus larvae. The visualisation and the inflation of the swim bladder occurred at 1 and 3 dph, respectively, in the P. argenteus, whereas these events occurred at 2 and 8 dph, respectively, in L. alexandri. Yolk granules were absorbed at 4 dph in P. argenteus and the 10 dph in L. alexandri. At 7 dph, the digestive tube was more differentiated in L. alexandri than P. argenteus and at 14 dph, the digestive system of both species had features of their eating habits: broad stomach and short intestine in L. alexandri, typical of carnivorous habits; stomach with a mechanical function and long intestine in P. argenteus, typical of detritivorous habits. The epithelial lining tissue, formed by a single layer of cells in the newly hatched larvae (0 dph), differentiated throughout the study, exhibiting scales in P. argenteus and numerous club cells in the middle epithelial region of L. alexandri at 39 dph. Undifferentiated gonads with somatic cells and primordial germ cells were observed at 39 dph, with caudal-cranial migration since 1 dph in both species. The anatomic changes during the ontogeny of P. argenteus and L. alexandri larvae are directly associated with the evolutionary history of each species, which explains their feeding habits, behaviour and distribution in the environment: Prochilodus argenteus is detritivorous and actively swims in the water column, whereas L. alexandri is carnivorous and inhabits bottom regions. At 39 dph neither species exhibited sexual differentiation.     

Unprecedented Mass Bleaching and Loss of Coral across 12° of Latitude in Western Australia in 2010–11

Background

Globally, coral bleaching has been responsible for a significant decline in both coral cover and diversity over the past two decades. During the summer of 2010–11, anomalous large-scale ocean warming induced unprecedented levels of coral bleaching accompanied by substantial storminess across more than 12° of latitude and 1200 kilometers of coastline in Western Australia (WA).

Methodology/Principal Findings

Extreme La-Niña conditions caused extensive warming of waters and drove considerable storminess and cyclonic activity across WA from October 2010 to May 2011. Satellite-derived sea surface temperature measurements recorded anomalies of up to 5°C above long-term averages. Benthic surveys quantified the extent of bleaching at 10 locations across four regions from tropical to temperate waters. Bleaching was recorded in all locations across regions and ranged between 17% (±5.5) in the temperate Perth region, to 95% (±3.5) in the Exmouth Gulf of the tropical Ningaloo region. Coincident with high levels of bleaching, three cyclones passed in close proximity to study locations around the time of peak temperatures. Follow-up surveys revealed spatial heterogeneity in coral cover change with four of ten locations recording significant loss of coral cover. Relative decreases ranged between 22%–83.9% of total coral cover, with the greatest losses in the Exmouth Gulf.

Conclusions/Significance

The anomalous thermal stress of 2010–11 induced mass bleaching of corals along central and southern WA coral reefs. Significant coral bleaching was observed at multiple locations across the tropical-temperate divide spanning more than 1200 km of coastline. Resultant spatially patchy loss of coral cover under widespread and high levels of bleaching and cyclonic activity, suggests a degree of resilience for WA coral communities. However, the spatial extent of bleaching casts some doubt over hypotheses suggesting that future impacts to coral reefs under forecast warming regimes may in part be mitigated by southern thermal refugia.     

Stress protein response in two sibling species of Marenzelleria (Polychaeta: Spionidae): is there an influence of acclimation salinity?

The induction and synthesis of stress proteins in the polychaete sibling species Marenzelleria viridis and M. neglecta was investigated at two different acclimation salinities (10 and 25 ppt). By in vitro labeling of dissected metameres with ³⁵S-methionine/cysteine and electrophoretic separation, four size classes of heat shock proteins (Hsps) were detected corresponding to 86, 78, 75 and 27 kDa. All Hsps, with the exception of Hsp86, represent a complex of multiple isoforms. The sibling species differed in three aspects of their heat shock response: (1) the induction temperature for Hsp75 synthesis was 25 °C and 30 °C in M. viridis and M. neglecta, respectively; (2) the relative level of synthesis of Hsp75 was higher in M. viridis; (3) the heat shock response was inactivated at a higher temperature in M. neglecta compared to M. viridis. The results showed that acclimation salinity had no explicit effect on Hsp synthesis in either species and that M. viridis was thermally more sensitive than its sibling species. We proposed that temperature, alone or in combination with other abiotic factors, plays a far greater role in the biogeographic distribution in Marenzelleria spp. than has been estimated so far.     

Paedomorphosis in two small species of toothed whales (Odontoceti): how and why?

To evaluate and assess the ontogenetic background for paedomorphosis in phocoenids, samples of 144 harbour porpoises, 81 white‐beaked dolphins, and 130 Commerson's dolphins were compared in terms of the development of epiphyseal fusion, cranial suture fusion, and ontogeny of cranial shape. Harbour porpoises and Commerson's dolphins terminated growth and development of all investigated traits sooner than white‐beaked dolphins, leading to lesser degrees of fusion of skeletal elements and less postnatal allometric development. The latter occurred even though shape in the two paedomorphic species developed at twice the rate relative to the size of white‐beaked dolphins. These observations imply that progenetic evolution has occurred convergently in phocoenid and Cephalorhynchus ancestors. The truncated ontogenies allow sexual maturity to be attained earlier and provide a greater reproductive potential. Both species inhabit similar temperate productive habitats and, hence, ecological factors are proposed to have supplied the selection pressures leading to progenesis. Constant prey availability must be a prerequisite for the observed phenomena because frequent food‐intake is necessitated by the limited capacity for energy storage and high heat‐loss entailed by the resulting small body sizes. Progenesis has rarely been proposed in mammal species. This may reflect rarity or that mammalian expressions of progenesis are less obvious. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 278–295.     

Conflict of use for multi-purpose tree species in the state of Pará, eastern Amazonia, Brazil

Although diversified forest management is promoted as a strategy aimed at slowing tropical deforestation, little is known about the viability of integrating timber and non-timber forest products in the same forest management plans. In this study we offer an initial characterization of multi-purpose tree species in the State of Pará, the principal Amazonian logging region. We identify the species used for both timber and non-timber extraction, and classify these according to their commercial value. We relate multi-purpose species to their ecological traits, the type of non-timber forest use and the fraction of the tree harvested. Although a high number of species present a potential conflict of use, this conflict is only relevant in four of them: D. odorata, T. serratifolia, T. impetiginosa and H. courbaril. Nevertheless, the nature and relevance of this conflict will ultimately depend on the importance that the non-timber use has for the livelihoods of forest-dependant people, the commercial value and the ecological resilience of these species.     

Precence of β-Carotene and Xantophylls in two species of the genus Niphargus (Crustacea: Amphipoda)

The presence of carotenoids in the Niphargus tatrensis Wrzesniowski and Niphargus aquilex schellenbergi Karaban has been investigated. In extracts separated by means of column and thin-layer chromatography, the following carotenoids were identified:

1. in Niphargus tatrensis: β-carotene, astaxanthin ester, rubixanthin, celaxanthin and astaxanthin.
2. in Niphargus aquilex schellenbergi: cantha-xanthin, astaxanthin ester, isozeaxanthin (only from Jeker), 4-keto-4′-hydroxy-β-carotene (only from Terzietebronbos), rubixanthin, celaxanthin and astaxanthin.

It was not possible to identifity the sexth fractions.     

How small is too small for small animals? Four terrestrial arthropod species in different-sized remnant woodlands in agricultural Western Australia

Island biogeography theory, and the 50/500 rule of genetics, have effectively devalued small habitat fragments for species conservation. Metapopulation theory has given new value to small remnants but data on species persistence are scarce. This study examined the capacity of very small and sheep-grazed remnants of eucalypt woodland in agricultural Western Australia to support remnant-dependent terrestrial arthropods. We surveyed 53 sheep-grazed remnants of wheatbelt wandoo Eucalyptus capillosa for the presence of four species of arthropod with different dispersal strategies (terrestrial versus aerial) and diet (predaceous vs. herbivorous): the harvester and mound-building termite Drepanotermes tamminensis, the wood-eating and mound-building termite Amitermes obeuntis, the predaceous and burrowing scorpion Urodacus armatus and the predaceous 'bull' ant Myrmecia nigriceps. All species with the exception of the scorpion disperse aerially, and all construct above-ground structures that are easily recognized. Remnants ranged in size from 50 m² to 21 000 m² (mean 1791 m²), in spatial isolation (distance to the nearest vegetation remnant) from 10 m to 500 m (mean 123 m) and in a length-to-width ratio (shape) from circular (mean ratio 1.0) to linear (mean ratio 4.0). Observations in small and grazed remnants were compared with observations made in six wandoo woodland sites within a large (1040 ha) and ungrazed remnant. The total number of target species was highly correlated with remnant area (r = 0.68). Remnant isolation and remnant shape had no apparent influence on the total number of target species. The minimum area of grazed remnants in which individual species were recorded followed the large predator Urodacus armatus (4515 m²) > smaller predator Myrmecia nigriceps (300 m²) > harvester termites Drepanotermes tamminensis (102 m²) > wood-eating termites Amitermes obeuntis (50 m²). With the exception of U. armatus which occurred only in three of the four largest grazed remnants, the occurrence of all other species increased from small to large grazed remnants, suggesting a remnant-size effect for all species. Remnant isolation or remnant shape had no apparent influence on the occurrence of any one species. The terrestrially dispersing scorpion persisted in remnants despite their isolation from other remnants from 200 m to 500 m. For both termite species, mound heights were significantly greater in large, ungrazed woodlands than in small and grazed woodlands. The incidence of mound abandonment in smaller and grazed remnants was considerably higher for harvester than for wood-eating termite colonies. This suggests differences in spatial requirements and possibly diet-related susceptibilities to fluctuations in food availability. The diameter of Myrmecia nigriceps nests showed no relationship with remnant size or isolation. This study demonstrated that even very small remnant woodlands on farms may play an important role in sustaining small native animals, either as stepping-stones for dispersing individuals (termites, ants) or in providing adequate habitat to sustain populations for longer periods (all four species).     

Observations of daytime births in two groups of red-handed howlers (Alouatta belzebul) on an island in the Tucuruí reservoir in eastern Brazilian Amazonia

Births were observed in two free-ranging groups of red-handed howlers (Alouatta belzebul) in eastern Brazilian Amazonia. Both events occurred in the early afternoon, and were relatively rapid and discrete. No other group members approached the females during parturition, nor attempted to interfere with the neonate in any way. Only one of the mothers ingested the placenta. This same female carried the neonate ventrally during the first month of life and then it was carried dorsally. The other infant was carried by its mother in a dorsal position from birth onward. Both infants survived their first month, but subsequently disappeared, in the second and fourth months of life. The precise causes of their death are unknown. In one case, we speculate that the infant's death was due to infestation by botfly larvae.     

Do floral odor profiles geographically vary with the degree of specificity for pollinators? Investigation in two sapromyophilous Arum species (Araceae)

We compared floral odour profiles among populations of two Arum species which show different degrees of specificity for their fly pollinators. Insects were collected from inflorescences in four populations of Arum italicum and two populations of Arum maculatum. In six Arum populations, we compared inflorescences odour profiles collected by Solid Phase Micro Extraction (SPME) and analysed by gas chromatography. We confirmed that from a pollination point of view, A. italicum is an opportunist species, as it is mainly pollinated by insects of the families Psychodidae, Chironomidae and Sciaridae, whereas A. maculatum is a specialist species, as it is 90% pollinated by Psychodidae. In all populations, Arum italicum was less attractive to pollinators than Arum maculatum. Floral odour profiles of A. italicum were not geographically structured among populations, suggesting a high gene flow or adaptation to a fluctuant guild of pollinators. On the contrary, odour profiles of A. maculatum varied between the two populations studied suggesting a lower gene flow or adaptation to different local pollinator preferences     

Seasonal differentiation — a conservative reproductive barrier in two grasslandGentianella (Gentianaceae) species

18 populations of the grassland biennialsGentianella amarella andG. campestris were cultivated to clarify the genetical vs. environmental components of the flowering phenology, and the reproductive isolation caused by seasonal differentiation. The influence of some environmental factors was tested. The seasonal variation persisted in cultivation, and the plants could normally be assigned to distinct aestival or autumnal groups, with no reproductive contact. Flowering phenology was affected by environmental factors, but not to such an extent that the reproductive isolation was broken. The observed phenological variation was not reflected by a corresponding variation in present management practices. Management history and possible non-anthropogenic factors are discussed as alternative explanations.     

Variation in susceptibility of Helicoverpa armigera (Hübner) and Helicoverpa punctigera (Wallengren) (Lepidoptera: Noctuidae) in Australia to two Bacillus thuringiensis toxins

Intra-specific variation in susceptibility of Helicoverpa armigera (Hübner) and Helicoverpa punctigera (Wallengren) in Australia to the Cry1Ac and Cry2Ab delta-endotoxins from Bacillus thuringiensis (Berliner) (Bt) was determined to establish a baseline for monitoring changes that might occur with the use of Bt cotton. Strains of H. armigera and H. punctigera were established from populations collected primarily from commercial farms throughout the Australian cotton belts. Strains were evaluated for susceptibility using two bioassay methods (surface treatment and diet incorporation) by measuring the dose response for mortality (LC50) and growth inhibition (IC50). The variation in LC50 among H. armigera (n=17 strains) and H. punctigera (n=12 strains) in response to Cry1Ac was 4.6- and 3.2-fold, respectively. The variation in LC50 among H. armigera (n=19 strains) and H. punctigera (n=12 strains) to Cry2Ab was 6.6- and 3.5-fold, respectively. The range of Cry1Ac induced growth inhibition from the 3rd to 4th instar in H. armigera (n=15 strains) was 3.6-fold and in H. punctigera (n=13 strains) was 2.6-fold, while the range of Cry2Ab induced growth inhibition from neonate to 3rd instar in H. armigera (n=13 strains) was 4.3-fold and in H. punctigera (n=12 strains) was 6.1-fold. Variation in susceptibility was also evaluated for two age classes (neonates and 3rd instars) in laboratory strains of H. armigera and H. punctigera. Neonates of H. punctigera had the same or higher sensitivity to Bt than 3rd instars. Neonates of H. armigera were more sensitive to Cry2Ab than 3rd instars, while being less sensitive to Cry1Ac than 3rd instars. Differences in the two methods of bioassay used affected relative sensitivity of species to Bt toxins, highlighting the need to standardize bioassay protocols.     

Photoconvertible protochlorophyll(ide) in vivo: A single species or two species in dynamic equilibrium?

The decreasing absorbances in vivo of protochlorophyll(ide) at 635 and 650 nm bear the same relationships to one another during photoconversion to chlorophyll(ide) a in the leaves of dark-grown barley seedlings, regardless of whether the actinic light is absorbed primarily at 630, 640 or 671 nm. Accordingly, the absorption bands at 635–637 and 650 nm of photoconvertible protochlorophyll(ide) are attributed to a single species of membrane-bound protochlorophyll(ide) molecule or, alternatively, to two species which are in dynamic equilibrium.     

Cross-species amplification of 44 microsatellite loci developed for Chaetodon trifascialis, C. lunulatus and C. vagabundus in 22 related butterflyfish species

Forty‐four microsatellite primers developed for three species of butterflyfish were cross‐tested against 22 related confamilial species. Amplification success and cross‐species transferability of these markers were moderately high. Between 24 and 37 loci were amplified successfully in each species, with a mean success rate per species of 71.7% (± 1.8 SE). Rates of amplification success were comparable among primers designed for the three source species, ranging from a mean success rate per species of 16.9 loci (± 0.8 SE) for Chaetodon trifascialis source loci to 13.7 loci (± 1.5 SE) for C. vagabundus source loci. Polymorphism rates were high (76.1%± 3.1 SE of all successfully amplified loci), and 10 loci were polymorphic in all successfully amplified species (Tri14, B11, C5, D3, D113, D6, D117, D120, D111, D118). The number of alleles per polymorphic locus ranged from 2 to 8, and the average number of alleles across all polymorphic loci and all species was 3.6 (± 0.07 SE). Polymorphism rates were higher overall in primers designed for C. vagabundus (89.9%± 3.9 SE). Overall cross‐testing success was lowest for Heniochus chrysostomus, the most phylogenetically divergent species. The significant cross‐testing reported here provides a valuable resource that will enable population genetics studies to be undertaken on a range of butterflyfishes without the need for expensive and time‐consuming de novo microsatellite development.     

Comparison of the physical properties of two Green Turtle (Chelonia mydas) nesting beaches (Akyatan and Samandağ) in the eastern Mediterranean (Reptilia: Cheloniidae)

The physical properities of sea turtle nesting beaches may strongly influence embryo development and hence conservation planning. In this study, we compared the characteristics of two nesting beaches of Green Turtles, Chelonia mydas, at Akyatan and Samanda? in southern Turkey. A total of 48 sand samples from 48 nests was examined and compared in respect to moisture content (M), temperature (TT), electrical conductivity (EC), salinity (S), total dissolved solution (TDS), pH, air ratio (AR), sand grain size together with distance from sea (DFS), depth (ND), incubation period (ID) and hatching success. Significant differences between the two areas were found in nest chamber moisture, conductivity, salinity, total dissolved solution and sand grain size. In a principal component analysis (PCA), the first component explained 45.1% of the variability and was dominated by the effects of the TDS, EC, S, pH and M. The second component explained 24.2 % of the variation and was dominated by the contributions of the TT, ID and ND. This is evidence that moisture plays a more important role than thermal properties in differentiating between the two beaches.     

Is Port Stephens,eastern Australia,a global hotspot for biodiversity of Aplysiidae (Gastropoda: Heterobranchia)?

Port Stephens, a large natural harbour on the central New South Wales (NSW) coast, provides ideal oceanographic and benthic conditions for the growth of marine algae and seagrasses, and this promotes a suite of herbivorous heterobranch sea slugs such as sea hares and sap-sucking sea slugs. In this article we document both historic and recent observations of sea hares (family Aplysiidae) from Port Stephens with the intention of recording species diversity. The western South Pacific region has the richest aplysiid fauna in the world, with 16 species now recorded in Port Stephens. This location is the most taxonomically diverse for this family in Australia. Despite this hotspot of aplysiid diversity, the taxonomy and nomenclature of 12 species is uncertain, a fact highlighted by a series of nomenclatural notes included in this article. We herein report the first observation of Petalifera sp. in Australian waters. Dolabrifera jacksoniensis Pilsbry, 1896 Pilsbry, H. (1896) Genus III. Dolabrifera Gray, 1847. Manual of Conchology series 1, volume 16, part 63, 113–160, pls 32–43. [Google Scholar] is newly synonymised with D. brazieri G.B. Sowerby II, 1870. Recent reports of southern range extensions for other heterobranch sea slugs, both in Port Stephens and elsewhere in NSW, highlight the importance of recording the existing aplysiid diversity in the port. Thus, any future alteration to species composition and range shifts driven by climate change may be detected.     

The ground parrot (Pezoporus wallicus Kerr) in south-eastern Australia: a fire-adapted species?

The ground parrot (Pezoporus wallicus) has a coastal distribution in Victoria and has declined in range since European colonization. Its habitat consists of two major vegetation communities: coastal heathland and sedgeland. These are further divided into various sub-communities. These habitats contained high densities of cyperaceous and restionaceous plants, the seeds of which form the bulk of the bird's diet. Seeds and small fruits of some dicotyledonous plants and grasses are also eaten. Seed production by sedges remains fairly constant over time in sedgelands but varies in heathland, depending on time since burning. This variation is reflected by parallel changes in ground parrot population density. Both long unburnt and very frequently burnt heathlands are unsuitable for ground parrots. The birds also require dense vegetation cover. Ground parrots appear to live in territorial breeding pairs with enforced natal dispersal. This is an adaptation to an environment where habitat is patchily distributed in space and variable in quality over time.     

Plant species microendemism and conservation of montane maquis in New Caledonia: two new species of Pancheria (Cunoniaceae) from the Roche Ouaïème

Two species of Pancheria (Cunoniaceae) described here, Pancheria minima J.C. Bradford and Pancheria ouaiemensis J.C. Bradford, draw attention to a recently recognized biodiversity pattern in New Caledonia. Montane maquis on acidic substrates, especially on the Roche Ouaïème, harbors numerous endemic species and is a rare and globally unique ecosystem. We cite 12 species, most described in the past several years, known only from the Roche Ouaïème in an area less than 10km². Overall, 27 species are known only from montane maquis and currently not found in a well-protected area. The major local threat to montane maquis habitat is anthropogenic fire, with climate change a possible long-term problem. Those montane maquis species known from one or two localities, occupying very small areas, and with declining habitat quality are critically endangered or endangered based on IUCN Red List criteria. Adding the Roche Ouaïème to the reserve system of New Caledonia is recommended to protect and manage a representative area of montane maquis on acidic substrates. A research strategy is proposed to identify species most at risk, locate possible unknown areas of montane maquis, and update taxonomic knowledge. A review of characters that vary among Pancheria species is provided, and the inflorescence architecture is described and diagramed. Both new Pancheria species occur at upper elevations in shrubby habitats. P. minima is remarkable in that the size of plants, leaves and reproductive parts is highly reduced compared to other known species.