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Zoology (Jena) ; 129: 59-65, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30170749


Vertebrate lever mechanics are defined by the morphology of skeletal elements and the properties of their muscular actuators; these metrics characterize functional diversity. The components of lever systems work in coordination ("functional integration") and may show strong covariation across evolutionary history ("evolutionary integration"), both of which have been hypothesized to constrain phenotypic diversity. We quantified evolutionary integration in a functionally integrated system - the lower jaw of sculpins and relatives (Actinopterygii: Cottoidei). Sculpins primarily rely on suction feeding for prey capture, but there is considerable variation in evasiveness of their prey, resulting in variation in anatomy of the lower jaw-closing mechanism. We used functionally-relevant linear measurements to characterize skeletal and muscular components of this system among 25 cottoid species and two outgroup Hexagrammoidei (greenling) species. We quantified evolutionary covariation and correlation of jaw-closing mechanical advantage (i.e., skeletal leverage) and muscle architecture (i.e., gearing) by correlating phylogenetically independent contrasts and fitting phylogenetically corrected generalized least squares models. We found no evidence of evolutionary covariation in muscle architecture and skeletal leverage. While we found a positive evolutionary correlation between out-lever length and adductor muscle fiber length, there was no significant evolutionary correlation between in-lever length and adductor muscle fiber length. We also found a positive evolutionary correlation between in- and out-lever lengths. These results suggest that skeletal morphology and muscle morphology contribute independently to biomechanical diversity among closely related species, indicating the importance of considering both skeletal and muscular variation in studies of ecomorphological diversification.

Peixes/anatomia & histologia , Peixes/genética , Arcada Osseodentária/anatomia & histologia , Músculo Esquelético/anatomia & histologia , Animais , Evolução Biológica , Fenômenos Biomecânicos , Comportamento Alimentar/fisiologia , Arcada Osseodentária/fisiologia , Músculo Esquelético/fisiologia , Especificidade da Espécie
Mol Ecol Resour ; 16(4): 957-65, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27087387


Bigheaded carps are invasive fishes threatening to invade the Great Lakes basin and establish spawning populations, and have been monitored using environmental DNA (eDNA). Not only does eDNA hold potential for detecting the presence of species, but may also allow for quantitative comparisons like relative abundance of species across time or space. We examined the relationships among bigheaded carp movement, hydrography, spawning and eDNA on the Wabash River, IN, USA. We found positive relationships between eDNA and movement and eDNA and hydrography. We did not find a relationship between eDNA and spawning activity in the form of drifting eggs. Our first finding demonstrates how eDNA may be used to monitor species abundance, whereas our second finding illustrates the need for additional research into eDNA methodologies. Current applications of eDNA are widespread, but the relatively new technology requires further refinement.

Carpas/genética , DNA/isolamento & purificação , Monitoramento Ambiental/métodos , Locomoção , Metagenômica/métodos , Reprodução , Água/química , Animais , Carpas/classificação , Carpas/fisiologia , DNA/genética , Indiana , Rios , Análise de Sequência de DNA
Environ Sci Technol ; 46(24): 13440-7, 2012 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-23171355


Concentrated animal feeding operation (CAFO) manure is a cost-effective fertilizer. In the Midwest, networks of subsurface tile-drains expedite transport of animal hormones and nutrients from land-applied CAFO manure to adjacent waterways. The objective of this study was to evaluate impacts of land-applied CAFO manure on fish populations and communities. Water chemistry including hormone, pesticide, and nutrient concentrations was characterized from study sites along with fish assemblage structure, growth, and endocrine disruption assessed in selected fish species. Although most CAFO water samples had hormone concentrations <1 ng/L, equivalent concentrations for 17ß-E2 and 17α-TB peaked at >30 ng/L each during the period of spawning, hatching, and development for resident fishes. CAFO sites had lower fish species richness, and fishes exhibited faster somatic growth and lower reproductive condition compared to individuals from the reference site. Fathead minnows (Pimephales promelas) exposed to CAFO ditchwater during early developmental stages exhibited significantly skewed sex ratios toward males. Maximum observed hormone concentrations were well above the lowest observable effect concentrations for these hormones; however, complexities at the field scale make it difficult to directly relate hormone concentration and impacts on fish. Complicating factors include the consistent presence of pesticides and nutrients, and the difference in temperature and stream architecture of the CAFO-impacted ditches compared to the reference site (e.g., channelization, bottom substrate, shallow pools, and riparian cover).

Ração Animal , Cyprinidae/crescimento & desenvolvimento , Monitoramento Ambiental , Esterco , Animais , Feminino , Geografia , Hormônios/análise , Indiana , Masculino , Praguicidas/análise , Dinâmica Populacional , Água/química , Qualidade da Água
J Wildl Dis ; 47(2): 455-8, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21441199


Batrachochytrium dendrobatidis is a fungal pathogen responsible for a potentially fatal disease of amphibians. We conducted a survey for B. dendrobatidis in the Appalachian Mountains of southwestern North Carolina, USA, from 10 June to 23 July 23 2009. Ventral skin swabs were collected from plethodontid salamanders (n=278) and real-time PCR was performed to test for the presence of B. dendrobatidis. We found no evidence of B. dendrobatidis, suggesting that B. dendrobatidis is absent or present in such low levels that it was undetected. If B. dendrobatidis was present at the time of our sampling, this survey supports evidence of low prevalence of B. dendrobatidis in North American headwater stream salamander populations.

Quitridiomicetos/patogenicidade , Dermatomicoses/veterinária , Urodelos/microbiologia , Animais , Animais Selvagens/microbiologia , Quitridiomicetos/isolamento & purificação , Dermatomicoses/epidemiologia , Dermatomicoses/microbiologia , Feminino , Masculino , North Carolina/epidemiologia , Vigilância de Evento Sentinela/veterinária
J Aquat Anim Health ; 22(1): 36-8, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20575363


This article reports the presence of an endocellular parasite, Polypodium sp., in the eggs of shovelnose sturgeon Scaphirhynchus platorynchus from the Wabash River, Indiana. The parasite was detected in 18% (2/11) of adult female sturgeon necropsied in April 2008. This constitutes the first record of this parasite in this host and in Indiana. The implications for the quality of the caviar remain unknown at this time.

Doenças dos Peixes/parasitologia , Hidrozoários , Óvulo/parasitologia , Doenças Parasitárias em Animais/parasitologia , Animais , Feminino , Doenças dos Peixes/epidemiologia , Peixes , Indiana/epidemiologia , Ovário , Doenças Parasitárias em Animais/epidemiologia , Rios
Fish Physiol Biochem ; 36(4): 923-32, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19941163


The development of a biomarker for rapid detection of intersex is desirable to researchers and fisheries managers alike. The first step is to identify a marker that has a dimorphic expression pattern. With a focus on sex-specific genes, we assessed the use of vitellogenin (vtg), forkhead box L2 (foxl2) and doublesex and mab-3-related transcription factor 1 (dmrt1) as molecular biomarkers for the identification of gender in shovelnose sturgeon (Scaphirhynchus platorynchus), a species known to have intersex individuals. A total of 61 shovelnose sturgeons were sampled from the Wabash River, Indiana, in April 2008. Results from our study indicate that least 7.5% of the non-females had testicular oocytes. Expression level of liver vtg was not higher in females than males, nor was gonad dmrt1 expression found to be higher in males. Only the expression of foxl2 was significantly greater in females and was found to be useful for identifying gender. Variation in expression levels of foxl2 in gonads of intersex fish limited its usefulness as a single biomarker for identifying this condition. Instead, the use of foxl2 to dmrt1 (foxl2 transcript abundance/dmrt1 transcript abundance) may be useful in the identification of intersex fish, as this ratio increased with increased feminization. We conclude that foxl2 can be used to identify sex, but not intersex sturgeon.

Peixes/genética , Expressão Gênica , Gônadas/metabolismo , Fígado/metabolismo , Caracteres Sexuais , Análise para Determinação do Sexo/veterinária , Análise de Variância , Animais , Pesos e Medidas Corporais , Primers do DNA/genética , Feminino , Peixes/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Perfilação da Expressão Gênica , Marcadores Genéticos/genética , Indiana , Masculino , Reação em Cadeia da Polimerase , Análise para Determinação do Sexo/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Vitelogeninas/genética , Vitelogeninas/metabolismo