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bioRxiv2017

Induction of Reproductive Behaviors by Exogenous Hormones in Captive Southern Rocky Mountain Boreal Toads, Anaxyrus boreas boreas

Loss of reproductive viability, physiologically and/or behaviorally, can have profound effects on the fitness of a captive population and conservation efforts. The southern rocky mountain (SRM) population of the boreal toad has declined over the past 35 years, making captive breeding necessary to protect and augment the species in the wild. In recent years, a notable reduction in the incidence of amplexus and viable offspring from the captive breeding population has been observed. Hormone treatment protocols to stimulate gamete release in males and females are established in this species and in vitro fertilization has been performed successfully. However, successful hormone stimulation of reproductive behaviors and natural fertilization has not been well documented. During the breeding season of 2012, 24 males and 24 female toads were selected from a population of over 600 captive animals. Both sexes were treated with Human chorionic gonadotropin (hCG) and Gonadotropin Releasing Hormone (GnRH) or phosphate buffered saline (PBS). Females were primed twice with 3.7IU/g hCG and then injected with an ovulatory dose (OvD) of 13.5 IU/ g BW (Body weight) hCG and 0.4 g/ g BW GnRH. Males were injected a single time with 10 IU/g BW hCG and 0.4 g/ g BW GnRH, 12 h after females received their OvD. In 2013, knowing the approximate time when females oviposited after hormone treatments, we tested the best time to induce amplexus and spermiation. Males were divided into 4 groups and injected at 4 different times: (a) 12 h before females OvD; (b) at the same time as OvD; (c) 12 h after OvD; (d) control injected with PBS. Results from 2012 indicated that oviposition was solely dependent on females receiving hormone treatments not males. However, in 2013 we found that the duration of amplexus significantly influenced oviposition (P>0.05), and males injected 12 h prior to females spent more time in amplexus than males injected at the same time or 12 h after the females received hormones. Promoting reproductive behaviors and synchronizing gamete deposition continues to be imprecise and may require more than exogenous hormones. The complexity of promoting breeding behaviors may require a closer assessment of the captive environment.

zoology↗

bioRxiv2017

A Migratory Divide In The Painted Bunting (Passerina ciris)

Divergence in migratory behavior is a potential mechanism of lineage divergence in sympatric populations and a key life history trait used in the identification of demographically independent units for conservation purposes. In the Painted Bunting (Passerina ciris), a North American songbird, populations on the Atlantic coast and interior southern United States are known to be allopatric during the breeding season, but efforts to map connectivity with wintering ranges in Mexico, Florida, and the Caribbean have been largely inconclusive. Using genomic and morphological data from natural history specimens and banded birds, we found evidence of three genetically differentiated populations with distinct wintering ranges and molt-migration phenologies. In addition to confirming that the Atlantic coast population remains allopatric throughout the annual cycle, we identified an unexpected migratory divide within the interior breeding range. Populations breeding in the Lower Mississippi River Valley winter on the Yucatan Peninsula, and are parapatric with other interior populations that winter in mainland Mexico and Central America. Across the interior breeding range, genetic ancestry is also associated with variation in wing length; suggesting that selective pressures may be promoting morphological divergence in populations with different migration strategies.

zoology↗

bioRxiv2017

Carrion Fly-Derived DNA Metabarcoding Is An Effective Tool For Mammal Surveys: Evidence From A Known Tropical Mammal Community

Metabarcoding of vertebrate DNA derived from carrion flies has been proposed as a promising tool for biodiversity monitoring. To evaluate its efficacy, we conducted metabarcoding surveys of carrion flies on Barro Colorado Island (BCI), Panama, which has a well-known mammal community, and compared our results against diurnal transect counts and camera-trapping. We collected 1084 flies in 29 sampling days, which were pooled into 102 DNA extractions. We then conducted metabarcoding with mammal-specific (16S) and vertebrate-specific (12S) primers targeting mtDNA, and sequenced these amplicons on Illumina MiSeq. For taxonomic assignment, we compared BLAST with the new program PROTAX, and we found PROTAX significantly improved species identifications. We detected 20 mammal, four bird, and one lizard species from carrion fly metabarcoding, all but one of which were previously known from BCI. Fly metabarcoding detected more mammal species than concurrent transect counts (29 sampling days, 13 species) and concurrent camera-trapping (84 sampling days, 17 species), and detected 67% of the number of mammal species documented by 8 years of transect counts and camera-trapping combined, although fly metabarcoding missed several abundant species. This study demonstrates that carrion fly metabarcoding is a powerful tool for mammal biodiversity surveys, and has the potential to detect a broader range of species than more commonly used methods.

zoology↗

bioRxiv2017

Extensive Sexual Wing Shape Dimorphism In Drosophila melanogaster, Ceratitis capitata, And Musca domestica

The ability of powered flight in insects facilitated their great evolutionary success allowing them to occupy various ecological niches. Beyond this primary task, wings are often involved in various premating behaviors, such as the generation of courtship songs and the initiation of mating in flight. These specific functions imply special adaptations of wing morphology, as well as sex-specific wing morphologies. Although wing morphology has been extensively studied in Drosophila melanogaster, a comprehensive understa nding of sexual wing shape dimorphisms and developmental plasticity is missing for other Diptera. Therefore, we raised flies of the three Diptera species Drosophila melanogaster, Ceratitis capitata and Musca domestica at different environmental conditions and applied geometric morphometrics to analyze wing shape. Our data showed extensive interspecific differences in wing shape, as well as a clear sexual wing shape dimorphism in all three species. We revealed an impact of different rearing temperatures wing shape in all three species, which was mostly explained by plasticity in wing size in D. melanogaster. Rearing densities had significant effects on allometric wing shape in D. melanogaster, while no obvious effects were observed for the other two species. Additionally, we do not find evidence for sex-specific response to different rearing conditions in all three species. We determined species-specific and common trends in shape alterations, and we hypothesize developmental and functional implications of our data. Contribution to the Field StatementThe size and shape of organisms and organs must be tightly controlled during development to ensure proper functionality. However, morphological traits vary considerably in nature contributing to phenotypic diversity. Such variation can be the result of evolutionary adaptations as well as plasticity for example as reaction to changing environmental conditions during development. It is therefore a major aim in Biology to unravel the processes that control differences in adult morphology. Insect wings are excellent models to study how organ size and shape evolves because they facilitate basic tasks such as mating and feeding. Accordingly, a tremendous variety of wings sizes and shapes evolved in nature. Additionally, plasticity in wing morphology in response to different rearing conditions has been observed in many insects contributing to phenotypic diversity. In this work we applied Geometric Morphometrics to study wing shape in the three Diptera species: the Mediterranean fruit fly Ceratitis capitata, the Vinegar fly Drosophila melanogaster and the housefly Musca domestica. Flies were raised in different temperature and density regimes that allowed us to study the effects of these environmental factors on wing shape. Additionally, in accordance with different mating behaviors of these flies, we observed a clear sexual shape dimorphism in all three species. Since the three studied species represent serious pests and disease vectors, our findings may contribute to existing and future monitoring efforts.

zoology↗

bioRxiv2017

Reef Fishes Of Praia do Tofo & Praia da Barra, Inhambane, Mozambique

The coral reefs around Praia do Tofo and Praia da Barra, southern Mozambique, are known for their aggregations of marine megafauna but few studies have examined their reef fish biodiversity. This study assesses for the first time the ichthyofaunal diversity of the seas around Praia do Tofo and Praia da Barra. Methods involved underwater observations during recreational dives between February and September 2016, and the use of photographic records from 2015. A total of 353 species, representing 79 families, were recorded from 16 patch reefs in the region. The area shows comparable species diversity to others in the southwestern Indian Ocean, suggesting these reefs are in good condition. But high primary productivity driven by coastal upwelling may make fish diversity and trophic structure unreliable measures of the health of these reefs. Future studies investigating the sustainability of this ecosystem would benefit from utilising a wide range of reef health measures.

zoology↗

bioRxiv2017

Genetic evidences for the impact of anthropogenic factors on honey bee diversity

Intense admixture of honey bee (Apis mellifera L.) populations is mostly attributed to migratory beekeeping practices and replacement of queens and colonies with non-native races or hybrids of different subspecies. These two practices are also heavily carried out in Anatolia and Thrace where 5 subspecies reside naturally.Here, we carried out an analysis of population structure of honey bees sampled from six different regions (n = 250) in order to test the genetic impacts of migratory beekeeping, queen and colony trade and conservation efficacy of isolated regions. A total of 30 microsatellite markers were used in four multiplex reactions.Direct genetic impact of migratory beekeeping was demonstrated first time based on a comparison of assignment of individuals to their geographically native populations where migratory colonies showed less fidelity. We found genetic evidence for them acting as a hybrid zone mobile in space and time, becoming vectors of otherwise local gene combinations.The effects of honey bee trade were revealed by the presence of very high introgression levels from the highly commercial Caucasian bees naturally limited to a narrow range. We also measured the direction and magnitude of this gene flow connected with bee trade.Comparison between regions that are either open to migratory beekeeping or not let us evaluate the status of isolated regions as centers of limited gene flow and showed the importance of establishing such regions.Despite signs of gene flow, our findings confirm high levels of geographically structured genetic diversity of four subspecies of honey bees in Turkey and emphasize the need to develop policies to maintain this diversity.Our overall results might potentially bear a wider interest to the community since they constitute an important attempt to quantify the effects of anthropogenic impacts on established patterns of honey bee diversity. Our measurable and justified findings on migratory beekeeping, queen and colony replacements as well as conservation implications will hopefully be of use for the decision makers and other stakeholders.Competing Interest StatementThe authors have declared no competing interest.View Full Text

zoology↗

bioRxiv2017

Risk factor analysis of equine strongyle resistance to anthelmintics

Intestinal strongyles are the most problematic endoparasites of equids as a result of their wide distribution and the spread of resistant isolates throughout the world. While abundant literature can be found on the extent of anthelmintic resistance across continents, empirical knowledge about associated risk factors is missing. This study brought together results from anthelmintic efficacy testing and risk factor analysis to provide evidence-based guidelines in the field. It involved 688 horses from 39 French horse farms and riding schools to both estimate Faecal Egg Count Reduction (FECR) after anthelmintic treatment and to interview farm and riding school managers about their practices. Risk factors associated with reduced anthelmintic efficacy in equine strongyles were estimated across drugs using a marginal modelling approach. Results demonstrated ivermectin efficacy (96.3% FECR), the inefficacy of fenbendazole (42.8% FECR) and an intermediate profile for pyrantel (90.3% FECR). Risk factor analysis provided support to advocate for FEC-based treatment regimens combined with individual anthelmintic dosage and the enforcement of tighter biosecurity around horse introduction that contributed to lower drug resistance risk by 1.75. Premises falling under this typology also relied more on their veterinarians suggesting they play an important role in the sustainability of anthelmintic usage. Similarly, drug resistance risk was halved in premises with frequent pasture rotation and with stocking rate below five horses/ha. This is the first empirical risk factor analysis for anthelmintic resistance in equids, whose findings should guide the implementation of more sustained strongyle management in the field.

zoology↗

bioRxiv2017

Adhesion of dry and wet cribellate capture silk

We demonstrate the impressive adhesive qualities of Uloborid spider orbweb capture when dry, which are lost when the nano-filament threads are wetted. A force sensor with a 50 nN-1mN detection sensitively allowed us to measure quantitatively the stress-strain characteristics of native silk threads in both the original dry state and after wetting by controlled application of water mist with droplet sizes ranging between 3 and 5 m and densities ranging between 104 and 105 per mm3. Stress forces of between 1 and 5 N/m2 in the native, dry multifilament thread puffs were reduced to between 0.1 and 0.5 N/m2 in the wetted collapsed state, with strain displacements reducing from between 2 and 5 mm in the dry to 0.10-0.12mm in the wetted states. We conclude that wetting cribellate threads reduce their van der Waals adhesion with implications on the threads adhesive strength under tension. This should be considered when discussing the evolutionary transitions of capture silks from the ancestral dry-state nanofilaments of the cribellate spider taxa to the wet-state glue droplets of the ecribellate taxa.

zoology↗

bioRxiv2017

Shifts in temperature influence how Batrachochytrium dendrobatidis infects amphibian larvae

Many climate change models predict increases in mean temperature, and increases in frequency and magnitude of temperature fluctuations. These potential shifts may impact ectotherms in several ways, including how they are affected by disease. Shifts in temperature may especially affect amphibians, a group with populations that have been challenged by several pathogens. Because amphibian hosts invest more in immunity at warmer than cooler temperatures and parasites may acclimate to temperature shifts faster than hosts (creating lags in optimal host immunity), researchers have hypothesized that a temperature shift from cold-to-warm might result in increased amphibian sensitivity to pathogens, whereas a shift from warm-to-cold might result in decreased sensitivity. Support for components of this climate-variability based hypothesis have been provided by prior studies of the fungus Batrachochytrium dendrobatidis (Bd) that causes the disease chytridiomycosis in amphibians. We experimentally tested whether temperature shifts before Bd exposure alter susceptibility to Bd in the larval stage of two amphibian species - western toads (Anaxyrus boreas) and northern red legged frogs (Rana aurora). Both host species harbored elevated Bd infection intensities under constant cold (15{degrees} C) temperature in comparison to constant warm (20{degrees} C) temperature. Additionally, both species experienced an increase in Bd infection abundance when shifted to 20{degrees} C from 15{degrees} C, compared to a constant 20{degrees} C but they experienced a decrease in Bd when shifted to 15{degrees} C from 20{degrees} C, compared to a constant 15{degrees} C. These results are in contrast to prior studies of adult amphibians that found increased susceptibility to Bd infection after a temperature shift in either direction, highlighting the potential for species and stage differences in the temperature-dependence of chytridiomycosis.

zoology↗

bioRxiv2017

Rapid changes in Atlantic grey seal milk from birth to desertion

True seals have the shortest lactation periods of any group of placental mammal. Most are capital breeders that undergo short, intense lactations, during which they fast while transferring substantial proportions of their body reserves to their pups, which they then abruptly desert. Milk was collected from Atlantic grey seals (Halichoerus grypus) periodically from birth until near desertion. Milk protein profiles matured within 24 hours or less, indicating the most rapid transition from colostrum to mature phase lactation yet observed. There was an unexpected persistence of immunoglobulin G almost until weaning, potentially indicating prolonged trans-intestinal transfer of IgG. Among components of innate immune protection were found fucosyllactose and siallylactose that are thought to impede colonisation by pathogens and encourage an appropriate gut microbiome. These oligosaccharides decreased from early lactation to almost undetectable levels by weaning. Taurine levels were initially high, then fell, possibly indicative of taurine dependency in seals, and progressive depletion of maternal reserves. Metabolites that could signal changes in the mothers metabolism of fats, such as nicotinamide and derivatives, rose from virtual absence, and acetylcarnitines fell. It is therefore possible that indicators of maternal metabolic strain exist that signal the imminence of desertion.

zoology↗

bioRxiv2017

Mineral analysis of complete dog and cat foods in the UK and compliance with European guidelines

The mineral content of complete pet food is regulated to ensure health of the companion animal population. A comprehensive analysis of adherence to these regulatory guidelines has not been conducted. We measured mineral composition of a range of complete wet (n=97) and dry (n=80) canine and feline pet food sold in the UK to assess compliance with EU guidelines. While a majority of foods complied with [≥]8 of 11 guidelines (99% and 83% for dry and wet food, respectively), many failed to provide nutritional minimum (e.g. Cu, 20 % of wet food) or exceeded nutritional maximum (e.g. Se, 76% of wet food). Only 6% (6/97) of wet and 39% (34/80) of dry food were fully compliant. Some foods (20-30% of all analysed) had mineral imbalances such as not having the recommended balance of Ca:P (between 1:1 to 2:1). Foods with high fish content had high levels of undesirable metal elements such as arsenic. The study highlights broad non-compliance of a range of popular pet foods sold in the UK with EU guidelines (95% and 61% of wet and dry foods, respectively). If fed exclusively and over an extended period, a number of these pet foods could impact the general health of companion animals.

zoology↗

bioRxiv2017

On the bioconversion of dietary carotenoids to astaxanthin and its distribution in the marine copepod, Tigriopus californicus

Red carotenoid-based coloration is widely distributed across marine and terrestrial animals and has taken a prominent role in studies of how phenotypic traits evolve in response to natural and sexual selection. Key to these studies is an understanding of the physiological mechanisms that give rise to red coloration, yet an ideal model system for such work has not been identified. The red marine copepod Tigriopus californicus is used as a model system for studies in ecotoxicology, genetics, and physiology, but the mechanisms involved in its bright red coloration have not been well studied. Like nearly all animals that display red carotenoid coloration, T. californicus likely convert yellow carotenoids present in their algal diet to red carotenoids. We conducted precursor/product feeding experiments to demonstrate that T. californicus bioconverts dietary carotenoids to the red carotenoid, astaxanthin. In separate treatment groups, copepods were fed carotenoids that are precursors to specific astaxanthin bioconversion pathways. We found that copepods from each precursor pigment group produced astaxanthin, and that the amount produced depended on which carotenoid was supplemented. We also describe the distribution of astaxanthin in developing egg sacs and show that the red color of the naupliar eyespot is not due to astaxanthin. We briefly discuss the potential of Tigriopus californicus to serve as a model system for the study of carotenoid metabolism in animals.

zoology↗

bioRxiv2017

Neotrygon indica sp. nov., the Indian-Ocean blue-spotted maskray (Myliobatoidei, Dasyatidae)

The blue-spotted maskray, previously N kuhlii, consists of up to eleven lineages representing separate species. Nine of these species (N australiae, N. bobwardi, N. caeruleopunctata, N. malaccensis, N moluccensis, N orientale, N. vali, N varidens, N westpapuensis) have already been formally described and two (Indian-Ocean maskray and Ryukyu maskray) remain undescribed. Here the Indian-Ocean maskray is described as a new species, Neotrygon indica sp. nov.

zoology↗

bioRxiv2017

Fossils know it best: using a new set of fossil calibrations to improve the temporal phylogenetic framework of murid rodents (Rodentia: Myomorpha: Muroidea: Muridae)

Murid rodents (Rodentia: Myomorpha: Muroidea: Muridae) represent the most diverse and abundant mammalian group. In this study, we reconstruct a dated phylogeny of the family using a multilocus dataset (six nuclear and nine mitochondrial gene fragments) encompassing 160 species representing 82 distinct murid genera from four extant subfamilies (Deomyinae, Gerbillinae, Lophiomyinae, and Murinae). In comparison with previous studies on murid or muroid rodents, our work stands out for the implementation of multiple fossil constraints within the Muridae thanks to a thorough review of the fossil record. Before being assigned to specific nodes of the phylogeny, all potential fossil constraints were carefully assessed; they were also subjected to several cross-validation analyses. The resulting phylogeny is consistent with previous phylogenetic studies on murids, and recovers the monophyly of all sampled murid subfamilies and tribes. Based on nine controlled fossil calibrations, our inferred temporal timeframe indicates that the murid family likely originated in the course of the Early Miocene, 23.0-16.0 million years ago (Ma), and that most major lineages (i.e. tribes) have started diversifying ca. 10 Ma. Historical biogeography analyses support the Paleotropical origin for the family, with an initial internal split (vicariance event) followed by subsequent migrations between Afrotropical and Indomalayan lineages. During the course of their diversification, the biogeographic pattern of murids is marked by several dispersal events toward the Australasian and the Palearctic regions, mostly from the Indomalaya. The Afrotropical region was also secondarily colonized at least three times from the Indomalaya, indicating that the latter region has acted as a major centre of diversification for the family.

zoology↗

bioRxiv2017

Changes in free amino acid concentrations and associated gene expression profiles in the abdominal muscle of kuruma shrimp Marsupenaeus japonicus reared at different salinity

Shrimps inhabiting around the coastal area can survive in a wide range of salinity. However, the molecular mechanisms involved in their adaptation to different environmental salinity have remained largely unknown. In the present study, we reared kuruma shrimp Marsupenaeus japonicus at 1.7 %, 3.4 % and 4.0 % salinity. After rearing for 6, 12, 24 and 72 h, we determined free amino acid concentrations in their abdominal muscle, and performed RNA-seq analysis on this muscle. The concentrations of free amino acids were clearly altered depending on salinity after rearing for 24 h. Glutamine and alanine concentrations were markedly increased following the increase of salinity. In association with such changes, many genes related to amino acid metabolism changed their expression levels. Notably, the increased glutamine content at high salinity appeared to be relevant to the increase of the expression level of the gene encoding glutamate-ammonia ligase which functions in the glutamine metabolism. Furthermore, the alanine content increased at high salinity was likely to be associated with the decrease in the expression levels of the alanine-glyoxylate transaminase gene. Thus, the changes in the concentration of free amino acids for osmoregulation in kuruma shrimp are considered to be regulated by the changes in the expression levels of genes related to amino acid metabolism.\n\nSummary statesmentKuruma shrimp Marsupenaeus japonicus changes free amino acid contents and associated gene expression levels in their muscle to adjust effectively to different salinity.

zoology↗

bioRxiv2017

Behavioral and Hematological Response of Clarias gariepinus juvenile exposed to Acute concentrations of Aqueous Extract of Siam Weed (Chloromolaena odorata) leaf as Anesthetic agent

This experiment was carried out to investigate the effect of Siam Weed (chloromelena odorata) on the heamatology of Clarias gariepinus juvenile. A total of one hundred and fifty (150) juvenile of Clarias gariepinus were randomly assigned to different concentrations of C. odorata leave aqueous extract in a completely randomize design (CRD). The concentrations were 50mg/l, 100mg/l, 150mg/l, 200mg/l. Distilled water (0.00 mg/l) was used as the control. The fish exhibited stressful behavior which was higher as the concentration of Chromolaena odorata leave extract increased. There was a gradual decrease with time until a state of calmness, which was subsequently followed by death. The effect on 96hr exposed period was recorded and blood samples collected at 24hr and 96hr interval. Result on hematological parameters revealed significant difference (P<0.05) among treatments with increase in exposure time for all the blood parameters. C. odorata at increased concentrations affected the behavior and hematology of C. gariepinus.

zoology↗

bioRxiv2017

Humpback whales of the Persian Gulf

The humpback whale has long been considered a rare straggler into the Persian Gulf, however new evidence contradicts this concept. We here critically review published and new records for Megaptera novaeangliae occurrence in the Gulf for the period 1883-2017. Of eight authenticated records (6 specimens, 2 live-sightings), seven are contemporary cases while one is a mid-Holocene specimen from UAE. An additional four are possible but unsubstantiated reports. Four regional, current, range states are confirmed, i.e. Iran, Iraq, Kuwait and Qatar. Four of the five newly reported cases are from Irans coastal waters. We conclude that the Persian Gulf is part of the habitual range of the Arabian Sea humpback whale population, and has been since at least the mid-Holocene. It is unknown whether frequent passage occurs through the Strait of Hormuz or whether whales are (semi)resident. The low abundance of this endangered population and frequent deleterious anthropogenic events, particularly ship strikes and net entanglements, are cause for major concern. In view of its historical and taxonomic relevance, the formal description of Megaptera indica Gervais, 1883, from Iraq, now thought to be a subspecies M. novaeangliae indica, is here translated from French.

zoology↗

bioRxiv2017

Odonata diversity of the eastern region of Bangladesh with four new addition to the Bangladeshi dragonfly fauna

A study was conducted in the eastern region to contribute to the Odonata fauna of Bangladesh. A total of 76 species belonging to 9 families have been recorded during the study period of April 2014 to July 2016. Three Zygopteran species e.g, Ceriagrion rubiae, Calicnemia imitans, Prodasineura autumnalis and one Anisopteran species e.g, Megalogomphus smithii have been newly discovered from Bangladesh. Megalogomphus genus have been first time recorded from Bangladesh.

zoology↗