scholarly journals Optimal fishing samplers to reveal the morphological structure of a fish assemblage in a subtropical tidal flat

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Carolina C. Siliprandi ◽  
Víctor M. Tuset ◽  
Antoni Lombarte ◽  
Marc Farré ◽  
Carmen L. D. B. Rossi-Wongtschowski

ABSTRACT Morphological characters of species are essential for assessing the functional structure of a fish assemblage, since differences between them, for example in body shape, are related to many functional and ecological traits (e.g., swimming, search for food, striking and capturing prey, evading predators, spawning). Globally, tidal flats are relevant to fish assemblages by offering feeding, refuge, and reproduction grounds. To analyze the morphofunctional structure of the fish assemblage from a tidal flat on the Brazilian coast, we conducted standardized sampling using nine different fishing gears. The geometric morphometric method was applied to describe the fish shapes and verify the morphological structure of the assemblage. Here, we present the influence/susceptibility of each gear type on the morphological diversity of the fish assemblage. The results indicated that beach seine, otter trawl, marginal encircling gillnet, and fish traps, together, were the most effective gears to represent the maximum morphological variability of fish inhabiting that tidal flat. Moreover, the assemblage showed high morphological redundancy considered as a resistance of the ecosystem for avoiding functional diversity loss, emphasizing the importance of complementary gear use when determining fish assemblages in a conservation context.

Author(s):  
Leona Lovrenčić ◽  
Vjera Pavić ◽  
Stefan Majnarić ◽  
Lucija Abramović ◽  
Mišel Jelić ◽  
...  

Austropotamobius torrentium is one of four native European crayfish species inhabiting Croatian freshwaters. Existence of eight divergent monophyletic mtDNA phylogroups was described within A. torrentium; six of them are distributed in Croatia, with the highest genetic diversity established in its northern-central Dinaric region. Recent small-scale study of the stone crayfish morphological variability indicated significant differences among different phylogroups. In the present study larger sample size, covering populations from five phylogroups, was analysed with the aim of determining whether there are morphological characteristics that reliably separate stone crayfish from different phylogroups. Aiming this, 245 stone crayfish were analysed through traditional (TM) and, for the first time, geometric morphometric (GM) analyses. Multivariate discriminant analyses included 24 TM characteristics per crayfish, while GM comprised analyses of 22 landmarks on the dorsal side of cephalon. Both methods revealed congruent results, and significant differences among phylogroups in analysed features were obtained, with the cephalon shape contributing the most to crayfish discrimination. Research confirmed that both approaches, combined with statistical methods, are useful in distinguishing and separating crayfish phylogroups. Findings of present study are compatible with the previous molecular findings; stone crayfish present several distinct evolutionary lineages whose species status are currently undefined and require urgent clarification.


2000 ◽  
Vol 48 (1) ◽  
pp. 09-27 ◽  
Author(s):  
Elizabeti Y. Muto ◽  
Lucy S. H. Soares ◽  
Carmen L. D. B. Rossi-Wongtschowski

The demersal fish community of the Channel and shelf of São Sebastião (SP), on the southeastern Brazilian coast, was investigated during the summer of 1994. The sampling was carried out usinga bottom otter trawl at 26 stations located between 8 m and 65 m in depth. Ninety-three species of 40 families were identified in the area. Sciaenids were the most prominent in number of species, abundance, and weight. Ctenosciaena gracilicirrhus, Paralonchurus, brasiliensis, and Cynoscion jamaicensis dominated in the catches. Cluster analysis showed three major groups of species and three groups of sites. The first group was composed of species found in the Channel and shallower areas of the inner shelf, the second of species associated with the inner shelf «50 m depth), and the third group of species fTom the outer shelf (> 50 m depth). Environrnental variables considered in Canonical Correspondence Analysis (CCA) explained 51 % of the variation in the species data. Bottom water temperature was the most important variable selected by CCA, accounting for 21% of the explainable variance. The results revealed that structure of the ichthyofauna was associated with water mass distribution. During the period studied, the area was occupied by the warm Coastal Water (CW), but cold South Atlantic Central Water (SACW) was detected over the bottom or the outer shelf, influencing the distribution and abundance ofthe main species.


2021 ◽  
Vol 83 (2) ◽  
pp. 241-255
Author(s):  
Julia Baumann

AbstractThe ability to disperse is one of the most important factors influencing the biogeography of species and speciation processes. Highly mobile species have been shown to lack geographic population structures, whereas less mobile species show genetically strongly subdivided populations which are expected to also display at least subtle phenotypic differences. Geometric morphometric methods (GMM) were now used to analyze morphological differences between European populations of a presumed non-phoretic, little mobile mite species in comparison to a highly mobile, phoretic species. The non-phoretic species Scutacarus carinthiacus showed a phenotypic population structure, whereas the phoretic species S. acarorum displayed homogeneity. These different patterns most probably can be explained by different levels of gene flow due to different dispersal abilities of the two species. GMM proved to be a sensitive tool that is especially recommendable for the analysis of (old) museum material and/or specimens in microscopic slides, which are not suitable for molecular genetic analysis.


2004 ◽  
Vol 52 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Henry L. Spach ◽  
Rodrigo S. Godefroid ◽  
César Santos ◽  
Roberto Schwarz Jr. ◽  
Guilherme M. L. de Queiroz

Annual variation in the fish assemblage characteristics on a tidal flat was studied in coastal Paraná, in southern Brazil. Fish were collected between August 1998 and July 1999, during the diurnal high tide and diurnal and nocturnal low tide of the syzygial (full moon) and quadrature (waning moon) tides, to characterize temporal change in assemblage composition. A total of 64,265 fish in 133 species were collected. The average number of species and individuals, biomass, species richness, diversity (mass) and equitability varied significantly over time . The dissimilarity of the assemblage was greatest in August, September and October in contrast with the period from November to January, with the lowest dissimilarity. The combined action of water temperature, salinity and wind intensity had a great influence over the structure of the fish assemblage.


Biologia ◽  
2015 ◽  
Vol 70 (10) ◽  
Author(s):  
Masoud Sheidai ◽  
Samira Sadeghi ◽  
Mahnaz-Arab Ameri ◽  
Ahmad-Reza Mehrabeian

AbstractThe present study aimed to reveal genetic diversity and population structure in three Onosma species i.e., Onosma bulbotrichum DC., O. elwendicum Wettst. and O. sericeum Willd. (Boraginaceae) growing in Iran. This study was performed to check if the ISSR molecular markers could be used in the Onosma species delimitation. We also investigated the infra-specific morphological variability and if we can identify infra-species taxonomic forms. The present study revealed within species genetic and morphological diversity. ISSR data could delimit the studied species as they were separated from each other in NJ tree, maximum parsimony and STRUCTURE analysis. AMOVA and Hickory tests produced significant genetic difference among the studied species. The Mantel test showed no correlation between genetic distance and geographical distance of the populations for all three species. Reticulation analysis and Nm estimation showed gene flow among these populations. We could identify a few ISSR loci that are adaptive. Data obtained can be used in conservation of these medicinal plants in Iran.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6098 ◽  
Author(s):  
Jiri Neustupa ◽  
Jan Stastny

Green microalgae of theMicrasteriaslineage are unicellular microorganisms with modular morphology consisting of successively differentiated lobes. Due to their morphological diversity and peculiar morphogenesis, these species are important model systems for studies of cytomorphogenesis and cellular plasticity. Interestingly, the phylogenetic structure of theMicrasteriaslineage and most other Desmidiales is poorly related to the traditional morphological characters used for delimitation of taxa. In this study, we focused on symmetry breaking between adjacent cellular lobes in relation to phylogeny of the studied species. While pronounced morphological asymmetry between the adjacent lobes is typical for some species, others have been characterized by the almost identical morphologies of these structures. We asked whether there is any detectable average shape asymmetry between the pairs of lobes and terminal lobules in 19Micrasteriasspecies representing all major clades of this desmidiacean lineage. Then, we evaluated whether the asymmetric patterns among species are phylogenetically structured. The analyses showed that the phylogeny was in fact strongly related to the patterns of morphological asymmetry between the adjacent cellular lobes. Thus, evolution of the asymmetric development between the adjacent lobes proved to be the key event differentiating cellular shape patterns ofMicrasterias. Conversely, the phylogeny was only weakly related to asymmetry between the pairs of terminal lobules. The subsequent analyses of the phylogenetic morphological integration showed that individual hierarchical levels of cellular morphology were only weakly coordinated with regard to asymmetric variation among species. This finding indicates that evolutionary differentiation of morphogenetic processes leading to symmetry breaking may be relatively independent at different branching levels. Such modularity is probably the key to the evolvability of cellular shapes, leading to the extraordinary morphological diversity of these intriguing microalgae.


2021 ◽  
Vol 46 (4) ◽  
pp. 1-13
Author(s):  
Cesar SANTOS ◽  
Roberto SCHWARZ JUNIOR ◽  
Helen Audrey PICHLER ◽  
Olímpio Rafael CARDOSO ◽  
Marcelo Renato LAMOUR ◽  
...  

The composition and structure of fish assemblages in the inner continental shelf of the Paraná State are affected by cold fronts and the rainfall regime. Data from fishing activities in this region, as well as the analysis of environmental characteristics, are the main tools available for understanding fish dynamics, under influence of increasing human activities. In order to better understand patterns and temporal variations in fish assemblages in the inner continental shelf of the Paraná State, a total of 24 double trawls were performed with an otter trawl between August 2000 and July 2001, in two sampling areas, the North area in front of the northern mouth of the Paranaguá Estuary Complex, and the South area, in front of the Leste beach. A total of 45,277 fish specimens belonging to 35 families and 97 species were caught. Sciaenidae was the most abundant family, with 37.1% of the total number of individuals caught, and with the highest richness (18 species). Statistical analyses evidenced significant differences in environmental characteristics and in fish fauna, and that both areas disturbances were observed in the fish assemblages during the dry and wet season, being more intense in the Southern area, disturbances that would be related to the shrimp fishing present in the two areas sampled in this study.


2015 ◽  
Author(s):  
Sive Finlay ◽  
Natalie Cooper

Morphological diversity is often studied qualitatively. However, to truly understand the evolution of exceptional diversity, it is important to take a quantitative approach instead of relying on subjective, qualitative assessments. Here, we present a quantitative analysis of morphological diversity in a Family of small mammals, the tenrecs (Afrosoricida, Tenrecidae). Tenrecs are often cited as an example of an exceptionally morphologically diverse group. However, this assumption has not been tested quantitatively. We use geometric morphometric analyses of skull shape to test whether tenrecs are more morphologically diverse than their closest relatives, the golden moles (Afrosoricida, Chrysochloridae). Tenrecs occupy a wider range of ecological niches than golden moles so we predict that they will be more morphologically diverse. Contrary to our expectations, We find that tenrec skulls are only more morphologically diverse than golden moles when measured in lateral view. Furthermore, similarities among the species-rich Microgale tenrec Genus appear to mask higher morphological diversity in the rest of the Family. These results reveal new insights into the morphological diversity of tenrecs and highlight the importance of using quantitative methods to test qualitative assumptions about patterns of morphological diversity.


2021 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Vina Eka Aristya

<p class="Abstract" align="center"><strong>ABSTRAK</strong></p><p class="Abstract"><em>Sesamum indicum</em> L. adalah salah satu tanaman alternatif penghasil minyak nabati penting. Pendekatan pemuliaan melalui induksi mutasi berusaha untuk menghasilkan variabilitas baru populasi wijen, yang secara umum tersusun dari individu homozigot. Karakter morfologi berguna untuk mengidentifikasi galur dan memastikan hasil pemuliaan mutasi. Tujuan penelitian ini adalah untuk mengevaluasi keragaman morfologi wijen hasil mutasi berdasarkan 26 karakter kualitatif. Penggalian informasi dengan metode analisis kelompok juga dikaji untuk menggambarkan variabilitas genetik pada 57 galur mutan wijen (jenis hitam dan putih) generasi M4 dan M5. Penelitian ini dilakukan dalam dua tahap: tahap pertama terdiri 18 galur generasi M4, dievaluasi pada Maret-Agustus 2015; tahap kedua terdiri atas 39 galur M5, ditanam pada November 2015 hingga April 2016. Pemeriksaan penampilan kualitatif mengikuti panduan <em>descriptor list</em> untuk wijen. Secara umum, penilaian representatif dari sifat kualitatif pada galur mutan wijen generasi M4 akan diikuti oleh keturunan generasi M5. Dendrogram dibangun untuk membedakan galur menjadi kelompok berdasarkan matriks tingkat kemiripan. Struktur populasi utama dari 57 galur berdasarkan sifat kualitatif dikategorikan dalam dua kelompok besar. Materi genotipe kelompok I diklasifikasikan menjadi dua sub-kelompok, terdiri 17 dan 31 galur. Sub-kelompok ini menjadi bagian distribusi genotipe terbesar. Kelompok II tersusun oleh 9 galur, mayoritas dari M4. Nilai korelasi antar karakter bervariasi antara 0,7176 hingga 1,0. Keragaman morfologi antar galur wijen dipengaruhi oleh sifat genetik dibandingkan faktor lingkungan. Studi ini membantu seleksi galur terpilih berdasarkan kestabilan fenotipe. Evaluasi keragaman struktur populasi wijen mutan bermanfaat untuk program pemuliaan.</p><p class="Abstract" align="center"><strong>ABSTRACT</strong></p><p class="Abstract"><em>Sesamum indicum</em> L. is one of the alternative crops that produces vegetative oil. The plant breeding approach through mutation induction could produce new genetic variability in sesame populations, which are generally composed of homozygous individuals. The study aims were to determine the diversity of sesame-mutant lines based on 26 qualitative characters. Cluster analysis method was carried out to describe the genetic variability of 57 sesame mutant lines (consist of black and white types) 4<sup>th</sup> (M4) and 5<sup>th</sup> generations (M5). The study was done in two phases, the first phases consisted of 18 M4 lines planted in March-August 2015; the second phase consisted 39 M5 lines planted in November 2015 to April 2016. Analyses of qualitative morphological characters followed the descriptors list for sesame. In general, a representative assessment of qualitative traits in M4 lines will be followed by the offspring of M5. Dendrogram showed that the 57 mutant lines categorized into two major clusters. Cluster I were composed of two sub-clusters, consisting 17 and 31 lines. This sub-cluster was the largest part of the genotype distribution. Cluster II composed of 9 lines, where M4 were the majority. The correlation value between characters ranged from 0.7176 up to 1.0. Morphological diversity among lines were largely influenced by genetic rather than environmental factors. This study supports the selection of lines based on phenotype stability. Evaluation of the structural diversity of mutant-sesame populations could be applied in sesame-breeding programs.</p>


2012 ◽  
Vol 10 (2) ◽  
pp. 417-424 ◽  
Author(s):  
Nara Tadini Junqueira ◽  
Cecília Gontijo Leal ◽  
Carlos Bernardo Mascarenhas Alves ◽  
Paulo Santos Pompeu

The rio das Velhas, located in central Minas Gerais State (Brazil), is a major tributary of the rio São Francisco. Despite several anthropogenic pressures, this basin supports more than 115 fish species. The aim of this study was to compare the morphological space occupied by fish assemblages in four regions (headwaters, upper, middle, and lower course) along the channel of the rio das Velhas. We try to answer the following question: Is there a change in the morphological organization of the fish along the longitudinal gradient of the river? Individuals from 67 species, collected at several sites in the basin from 1999 to 2008, were measured for 11 morphological attributes related to swimming behavior and habitat use. Through the graphs, the first two dimensions of the PCA suggest that the morphological volume occupied by the headwaters region is smaller than the other sections, because of the low richness of the site. However, morphological hypervolumes of the four reaches analyzed by Euclidean distances were not statistically different. The results indicated that only the density of morphological types increases along the rio das Velhas, and there is no difference between the headwaters and upper courses. Therefore, in order to use functional groups related to the morphology of the species as tools to take measures for the conservation and revitalization of the rio das Velhas, it is necessary analyze the density of species within these groups, as well as their composition.


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