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Understanding the Diversification of Central American Freshwater Fishes Using Comparative Phylogeography and Species DelimitationBagley, Justin C 01 December 2014 (has links) (PDF)
Phylogeography and molecular phylogenetics have proven remarkably useful for understanding the patterns and processes influencing historical diversification of biotic lineages at and below the species level, as well as delimiting morphologically cryptic species. In this dissertation, I used an integrative approach coupling comparative phylogeography and coalescent-based species delimitation to improve our understanding of the biogeography and species limits of Central American freshwater fishes. In Chapter 1, I conducted a literature review of the contributions of phylogeography to understanding the origins and maintenance of lower Central American biodiversity, in light of the geological and ecological setting. I highlighted emerging phylogeographic patterns, along with the need for improving regional historical biogeographical inference and conservation efforts through statistical and comparative phylogeographic studies. In Chapter 2, I compared mitochondrial phylogeographic patterns among three species of livebearing fishes (Poeciliidae) codistributed in the lower Nicaraguan depression and proximate uplands. I found evidence for mixed spatial and temporal divergences, indicating phylogeographic “pseudocongruence” suggesting that multiple evolutionary responses to historical processes have shaped population structuring of regional freshwater biota, possibly linked to recent community assembly and/or the effects of ecological differences among species on their responses to late Cenozoic environmental events. In Chapter 3, I used coalescent-based species tree and species delimitation analyses of a multilocus dataset to delimit species and infer their evolutionary relationships in the Poecilia sphenops species complex (Poeciliidae), a widespread but morphologically conserved group of fishes. Results indicated that diversity is underestimated and overestimated in different clades by c. ±15% (including candidate species); that lineages diversified since the Miocene; and that some evidence exists for a more probable role of hybridization, rather than incomplete lineage sorting, in shaping observed gene tree discordances. Last, in Chapter 4, I used a comparative phylogeographical analysis of eight codistributed species/genera of freshwater fishes to test for shared evolutionary responses predicted by four drainage-based hypotheses of Neotropical fish diversification. Integrating phylogeographic analyses with paleodistribution modeling revealed incongruent genetic structuring among lineages despite overlapping ancestral Pleistocene distributions, suggesting multiple routes to community assembly. Hypotheses tests using the latest approximate Bayesian computation model averaging methods also supported one pulse of diversification in two lineages diverged in the San Carlos River, but multiple divergences of three lineages across the Sixaola River basin, Costa Rica, correlated to Neogene sea level events and continental shelf width. Results supported complex biogeographical patterns illustrating how species responses to historical drainage-controlling processes have influenced Neotropical fish diversification.
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Distribution of larval fishes in the Winfield Pool, Kanawha River, and direct impacts of commercial navigation traffic on larval fish survivalOdom, Michael Cooper 20 November 2012 (has links)
Distributions of larval fishes in the Winfield Pool, Kanawha River, West Virginia, were determined by sampling two sites with bongo and push nets. Cyprinids, clupeids, and <i>Aplodinotus grunniens</i> dominated collections. Main channel densities were a fraction of the densities along the shoreline, indicating the importance of the shoreline as a nursery. Diel trends in abundance were evident for several taxa, but were likely caused by diel changes in gear avoidance and distribution of larvae. Vertical trends in abundance were apparent for several taxa at the deeper and more lentic sampling site (lower pool). <i>Aplodinotus grunniens</i> were generally more abundant near the bottom, especially during daylight. Cyprinids were more abundant near the bottom in mid-June, but displayed no vertical trends on other sampling dates. Clupeids were more abundant at middepth or surface during daylight, while equally dispersed or near the bottom at night. Vertical trends were not evident at the shallower and more lotic site (upper pool) except for <i>Aplodinotus grunniens</i>, which displayed the same preference for the bottom, as at the lower site. / Master of Science
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Reproductive styles of Osteoglossomorpha with emphasis on Notopterus notopterus and Osteoglossum bicirrhosumYanwirsal, Honesty 17 June 2013 (has links)
Die Osteoglossomorpha stellen eine basale Gruppe der Teleostei dar mit einer Mischung von plesiomorphen und apomorphen Merkmalen bezogen auf Reproduktion und ontogenetische Entwicklung. Bezüglich reproduktiver Gilden und ontogenetischer Entwicklung gibt es immer noch nur begrenzte Daten zu dieser Gruppe. Der größte Teil tiefer gehender Studien bezieht sich auf Mormyriden, detaillierte Beschreibungen und experimentelle Daten sind kaum vorhanden bei den anderen Gruppen sowie bei Notopterus notopterus und Osteoglossum bicirrhosum. Im Rahmen dieser Untersuchung wird zum ersten Mal eine detaillierte Beschreibung der ontogenetischen Entwicklung dieser beiden Arten auf der Basis von Laborzuchten vorgestellt. Nur bei N. notopterus gelangen Zuchtexperimente unter Laborbedingungen. Die experimentellen Daten zeigten, dass die Umweltparameter abnehmende Leitfähigkeit, Erhöhung des Wasserstandes und leichte Temperaturvariation keinen Einfluss auf Gonadenentwicklung oder Balzverhalten bei N. notopterus hatten. Die frisch abgelegten, klebrigen Eier von 3.8-4 mm Größe werden vom Männchen bis zum Schlupf bewacht. Die Eihülle besitzt äußere Rillen, die ringförmig um die Mikropyle herum angeordnet sind. Das Schlüpfen erfolgt im Alter von 168-204 Stunden. In dieser Studie wird zum ersten Mal eine Methode zur erfolgreichen Aufzucht von O. bicirrhosum unter Laborbedingungen bei 28 °C vorgestellt. Die nicht-klebrigen Eier von 12 mm Größe besitzen eine transparente Eihülle. Das Schlüpfen erfolgt im Alter von 162-166 Stunden und die geschlüpften Embryonen haben eine Länge von 16 mm. Bei O. bicirrhosum findet sich keine Larval-Periode; auf die Embryonal-Periode folgt sofort die Juvenil-Periode: Die Ontogenese kann somit als direkte Entwicklung klassifiziert werden. N. notopterus hingegen ist gekennzeichnet durch eine intermediäre Entwicklung unter Bezug auf Reproduktionsstrategien da sie eine höhere Anzahl von mittelgroßen Eiern produzieren bei gleichzeitiger Brutpflege. / The Osteoglossomorpha represent a basal group of teleostean fish comprising taxa with a mixture of both plesiomorphic and apomorphic characters of reproduction and ontogenetic development. Concerning reproductive styles and ontogenetic development of this group, there are still very limited data available so far. Most in depth studies are available for mormyrids, but detailed descriptions and experimental data remain scarce in the other groups as in Notopterus notopterus and Osteoglossum bicirrhosum. This study will describe in detail for the first time the ontogenetic development of these two species in laboratory-reared specimens. Only N. notopterus succeeded in the breeding experiment. Experimental data demonstrated that the environmental factors decreasing conductivity, slight variation of temperature, and water level have no influence on gonad development or courtship behaviour in N. notopterus. Newly spawned 3.8–4 mm adhesive eggs are guarded by the male until hatching. The egg envelope has external ridges, which are centred around the micropyle. Hatching occurs within 168–204 hours. For the first time, this study describes a method of successfully raising O. bicirrhosum at 28 °C under laboratory conditions. The non-adhesive eggs measure 12 mm with a transparent egg envelope. Hatching occurs around 162–166 hours and newly hatched embryos measure 16 mm. Actually there is no larval period found in O. bicirrhosum. The embryonic period is directly followed by the juvenile period and ontogeny can be characterized as direct development. N. notopterus is classified as intermediate species in an interpretation at reproductive strategies since they produce a higher number of medium-sized eggs and show parental care.
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Relações filogenéticas das espécies do gênero Rineloricaria Bleeker, 1862 (Siluriformes, Loricariidae, Loricariinae) / Phylogenetic relationships of the species of the Rineloricaria Bleeker, 1862 (Siluriformes, Loricariidae, Loricariinae)Fichberg, Ilana 17 December 2008 (has links)
As espécies do gênero Rineloricaria são representantes típicos da subfamília Loricariinae, família Loricariidae, tradicionalmente caracterizada pela presença de odontódios recobrindo o corpo, corpo fortemente deprimido e ausência de nadadeira adiposa. Rineloricaria compreende 65 espécies nominais, sendo o gênero mais rico em espécies na subfamília Loricariinae. Estudos filogenéticos prévios sobre Loricariidae não concordaram sobre a hipótese de monofiletismo e posicionamento filogenético de Rineloricaria entre outros Loricariinae. Os objetivos deste trabalho foram testar o monofiletismo do gênero e determinar seu posicionamento entre outros Loricariinae. Um estudo filogenético incluindo 36 espécies de Rineloricaria e 181 caracteres foi realizado utilizando parcimônia estrita. Os principais dados para análise foram derivados de morfologia esquelética e morfologia externa. O grupo externo incluiu uma quantidade representativa de gêneros considerados proximamente relacionados à Rineloricaria, sendo Neoplecostomus microps o táxon mais externo e ponto de enraizamento. Os resultados indicaram que Rineloricaria é monofilético e grupo-irmão dos outros Loricariinae. Doze sinapomorfias sustentam o monofiletismo de Rineloricaria. Dentre estas, uma sinapomorfia exclusiva é um processo dorso-mesial bem desenvolvido no quarto osso faringobranquial. Outras sinapomorfias não exclusivas para o gênero são: uma grande placa pré-anal trapezoidal circundada por três placas poligonais e caracteres específicos de dimorfismo sexual. / The species of Rineloricaria are typical members of Loricariinae subfamily, family Loricariidae, traditionally characterized by the presence of odontodes covering the body, strongly depressed body and absence of adipose fin. Rineloricaria comprises 65 nominal species and it is the most speciesrich genus in the subfamily Loricariinae. Previous phylogenetic studies on Loricariidae have not agreed on the putative monophyly and phylogenetic position of Rineloricaria among other Loricariinae. The objectives of this work were to test the monophyly of the genus and to determine its position among other Loricariinae. A phylogenetic study including 36 species of Rineloricaria and 181 characters was conducted using strict parsimony. The primary data for the analysis came from skeleton and external morphology. The outgroup included a number of representatives of genera previously considered as closely related to Rineloricaria, with Neoplecostomus microps as the most distant outgroup and rooting point. The results indicate that Rinolericaria is monophyletic and sister group to all other Loricariinae. Twelve sinapomorphies support the monophyly of Rineloricaria. Unique among them is the presence of a well-developed dorso-mesial process on the fourth pharyngobranchial bone. Other non-unique synapomorphies for the genus include: a great trapezoidal preanal plate surrounded by three polygonal plates and some specific dimorphic sexual features.
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Composi??o e estrutura das comunidades de metazo?rios parasitos de sete esp?cies de peixes do Reservat?rio de Lajes, Estado do Rio de Janeiro, Brasil / Composition and community structure of the metazoan parasites of seven fishes species from Lajes Reservoirs in the State of Rio de Janeiro, BrazilParaguass?, Aline Rodrigues 21 February 2006 (has links)
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Previous issue date: 2006-02-21 / Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / From April 2002 to July 2003, 296 freshwater fishes from Lajes Reservoirs in the State
of Rio de Janeiro, Brazil (22?42 - 22?50 S, 43?53 - 44?05 W) were necropsied to study
their community metazoan parasites: 39 Astyanax bimaculatus (Linnaeus, 1758), 79 A.
fasciatus (Cuvier, 1819), 65 Geophagus brasiliensis (Quoy & Gaimard, 1824), 23
Hypostomus affinis (Steindachner, 1877), 26 Hoplias malabaricus (Bloch, 1794), 30
Loricariichthys castaneus (Castelnau, 1855) and 34 Trachelyopterus striatulus
(Steindachner, 1877). The majority specimens of G. brasiliensis (81.5%), H. affinis
(95.6%) and H. malabaricus (84.6%) was parasitized by one or more metazoan species.
In A. bimaculatus, A. fasciatus, L. castaneus and T. striatulus 41%, 39.2%, 56.7 and
14.7% of specimens were parasitized, respectively.Ten different metazoan parasites
species were collected: 2 in A. bimaculatus, 3 in A. fasciatus, 6 in G. brasiliensis, 3 in
H. affinis, 4 in H. malabaricus, 4 in L. castaneus and 1 in T. striatulus. Six species were
common in at least two communities. The glossiophonid was collected in 6
communities. The larval stage of digeneans were the majority of the parasite specimens
collected in H. malabaricus and L. castaneus with 45.9% and 80.4%, respectively. In A.
bimaculatus and A. fasciatus the nematodes were the majority of the parasite specimens
collected, while in G. brasiliensis and H. affinis the hirudine glossiophonid was the
majority of the parasite specimens collected. Only one spcecies of monogenean was
collected in T. striatulus. The parasite of 7 host species showed the typical aggregate
pattern of distribution. Two cases of negative correlation between host s total length and
prevalence and parasite abundance were found. The parasite community of L. castaneus
showed the higher values of mean intensity, index of dispersion and higher values of
diversity. While the parasite community of H. affinis showed the higher values of mean
abundance and the mean parasite species richness. Only in A. fasciatus and L. castaneus
the abundance and parasite species richness showed positive correlations with the host s
total length. Geophagus brasiliensis was the species with higher number of species:
ectoparasites (3), adult endoparasites (1) and larval stage of endoparasites (2). The
parasite communities of the studied fishes showed scarcity of significant correlation of
parasitic abundance, scpecies richness and diversity and the size of the host. The low
scpecies richness and diversity of parasite communities could be attribute by
oligotrophic characteristics of the Lajes Reservoirs. / Entre abril de 2002 e julho de 2003, foram necropsiados 296 esp?cimes de peixes: 39
Astyanax bimaculatus (Linnaeus, 1758), 79 A. fasciatus (Cuvier, 1819), 65 Geophagus
brasiliensis (Quoy & Gaimard, 1824), 23 Hypostomus affinis (Steindachner, 1877), 26
Hoplias malabaricus (Bloch, 1794), 30 Loricariichthys castaneus (Castelnau, 1855) e
34 Trachelyopterus striatulus (Steindachner, 1877) provenientes do Reservat?rio de
Lajes (22?42 - 22?50 S, 43?53 - 44?05 O), Estado do Rio de Janeiro, Brasil, para
estudo das suas comunidades parasit?rias. A maioria dos esp?cimes de G. brasiliensis
(81,5%), H. affinis (95,6%) e H. malabaricus (84,6%) estavam parasitados por pelo
menos uma esp?cie de metazo?rio. Em A. bimaculatus, A. fasciatus, L. castaneus e T.
striatulus 41%, 39,2%, 56,7% e 14,7% dos esp?cimes estavam parasitados,
respectivamente. Foram coletadas 10 diferentes esp?cies de metazo?rios parasitos: 3
digen?ticos, 1 monogen?tico, 2 nemat?ides, 1 cop?pode, 1 hirud?neo, 1 bivalve e 1
is?pode. Seis esp?cies de metazo?rios parasitos foram comuns a pelo menos duas
comunidades. O glossiphon?deo foi encontrado em seis das sete comunidades estudadas.
Os est?gios larvais de digen?ticos corresponderam ? maioria dos esp?cimes coletados
em H. malabaricus e L. castaneus com 45,9% e 80,4%, respectivamente. Em A.
bimaculatus e A. fasciatus os nemat?ides corresponderam a maioria dos esp?cimes
coletados, enquanto em G. brasiliensis e H. affinis o glossiphonideo correspondeu a
maioria dos esp?cimes coletados. Apenas uma esp?cie de monogen?tico foi coletada em
T. striatulus. As comunidades de metazo?rios parasitos dos sete peixes estudados
apresentaram t?pico padr?o de distribui??o agregada. Apenas o glossiphonideo
apresentou correla??o negativa entre a abund?ncia e a preval?ncia parasit?rias e o
comprimento total em H. malabaricus e L. castaneus, respectivamente. A comunidade
parasit?ria de L. castaneus apresentou os maiores valores de intensidade m?dia, ?ndice
de dispers?o e diversidade. Enquanto a comunidade parasit?ria de H. affinis apresentou
os maiores valores de abund?ncia m?dia e riqueza parasit?ria. Apenas em A. fasciatus e
L. castaneus a abund?ncia e a riqueza parasit?ria apresentaram correla??o positiva com
o comprimento total do hospedeiro. Geophagus brasiliensis foi o hospedeiro com o
maior n?mero de esp?cies de parasitos: ectoparasitos (3), endoparasitos adultos (1) e
est?gios larvais de endoparasitos (2). As comunidades parasit?rias dos peixes estudados
apresentaram escassez de correla??o entre a abund?ncia, riqueza parasit?ria e
diversidade com o comprimento total dos hospedeiros. Os baixos valores de riqueza e
diversidade das comunidades parasit?rias podem ser atribu?dos as caracter?sticas
oligotr?ficas do Reservat?rio de Lajes.
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Environmental stability : its role in structuring fish communities and life history strategies in the Fortescue River, Western AustraliaBeesley, Leah Unknown Date (has links)
[Truncated abstract] This study investigated the organisational role of environmental stability on the fish communities that inhabit the Fortescue River, an intermittent and variable system in north-Western Australia. It did so by examining the relationships between pool stability (measured by persistence of water through time, and variation in maximum pool depth through time) and the number and type of species within pools, temporal fluctuations in total fish abundance and intra-specific abundance, population size frequency distributions, and growth rate. It also examined the association between life history traits and the stability of the environments occupied within the river, and the stability of the river at large. The results indicated that environmental stability was the major factor structuring the fish communities. Among-pool comparisons revealed that unstable pools contained fewer species, a greater fraction of juvenile size classes, and underwent greater fluctuations in total and intra-specific numerical abundance through time, than stable pools . . . Stability affected community structure by determining (or describing) the probability that a pool would undergo periods of extreme shrinkage, that is, the likelihood that fish will be exposed to extreme physico-chemical fluctuations and complete eradication. While the physical environment (acting through stability) primarily structured the fish communities of the Fortescue River there was indirect evidence that even within this variable river system, biological interactions played a role, albeit minor. Future investigations into the role of environmental stability will benefit from the use of accepted and quantitative methods by all stream ecologists.
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Biodiversidade de parasitas de peixes da família Loricariidae (Teleostei Siluriformes) procedentes do rio Sapucaí-Mirim, Brasil /Franceschini, Lidiane. January 2016 (has links)
Orientador: Reinaldo José da Silva / Resumo: Peixes da família Loricariidae (Siluriformes) apresentam grande plasticidade fenotípicaintraespecífica durante toda sua ontogenia. O conhecimento limitado sobre os aspectosbiológicos, padrões biogeográficos e elevada variabilidade morfológica destes peixesdificultam estudos sobre a biodiversidade acerca deste grupo, incluindo estudos sobre afauna parasitária. Assim, o objetivo deste estudo foi realizar levantamento dabiodiversidade de parasitas de peixes da família Loricariidae em áreas sob a influência daconstrução de Pequenas Centrais Hidrelétricas (PCHs) no rio Sapucaí-Mirim, Estado deSão Paulo, Brasil. Ademais, avaliar a estrutura das comunidades parasitárias doshospedeiros analisados (ao nível de infracomunidade e comunidade componente) epossíveis mudanças na abundância das infracomunidades baseadas em variáveisexplanatórias (espaciais, temporais e fatores intrínsecos ao hospedeiro). Para tanto, duranteos anos de 2012 e 2013 foram realizadas duas amostragens anuais (período seco/chuvoso),em oito áreas amostrais situadas nos reservatórios de três PCHs: Palmeiras, Anhanguera eRetiro. Foram necropsiados 334 loricarídeos pertencentes a 10 espécies: Loricaria prolixa,Hypostomus margaritifer, Hypostomus heraldoi, Hypostomus strigaticeps, Hypostomusregani, Hypostomus ancistroides, Hypostomus cf. margaritifer, Hypostomus topavae,Hypostomus aff. topavae, além de uma espécie não identificada pertencente ao gêneroHypostomus. Foram encontrados 29 ta... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Loricariid fishes (Siluriformes) presents great intraspecific phenotypic plasticity throughouttheir ontogeny. The limited knowledge about the biological aspects, biogeographic patternsof distribution and high morphological variability of these fishes make the studies onbiodiversity of this group difficult, including that about parasites. Therefore, the aim of thisstudy was to survey the biodiversity of parasites of Loricariidae fishes from an area underthe influence of the construction of Small Hydro Power Plants (SHPPs) in the Sapucaí-Mirim River, São Paulo State, Brazil. Moreover, the study evaluated the structure ofparasitic communities of these hosts (at both the component community andinfracommunity levels), assessing the possible variation in infracommunity abundanceamong sites and fish species based on explanatory variables (spatial, temporal, and hosttraits). During 2012 and 2013, two annual samples (dry/rainy seasons) were carried out, ineight sampling sites situated in the reservoirs of three SHPPs: Palmeiras, Anhanguera, andRetiro. Specimens of Loricaria prolixa, Hypostomus regani, Hypostomus ancistroides,Hypostomus strigaticeps, Hypostomus heraldoi, Hypostomus margaritifer, Hypostomus cf.margaritifer; Hypostomus topavae; Hypostomus aff. topavae and Hypostomus sp., wereanalyzed, totaling 334 fishes. Twenty-nine taxa were found, totaling 15,957 parasitespecimens, and Monogena was the dominant group, which showed the greatest richness ... (Complete abstract click electronic access below) / Doutor
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Tasemnice čeledi Gryporhynchidae z Afriky / Tapeworms of family Gryporhynchidae from AfricaHAASOVÁ, Ivana January 2009 (has links)
Morphological-taxonomical study of gryporhynchid cestodes from Africa is presented. New material from Kenya, Senegal and Sudan was studied and we belong to 17 species in 8 orders - Amirthalingamia macracantha (Joyeux et Baer, 1935) Bray, 1974; Anomotaenia riccii (Fuhrmann et Baer, 1943) Baer et Bona, 1960; Cyclustera magna (Baer, 1959) Bona, 1975; Cyclustera sp.; Dendrouterina macrosphincter (Fuhrmann, 1909) Baer et Bona, 1960; Neogryporhynchus sp.; Paradilepis lloydi (Southwell, 1926) Spasski, 1954; Paradilepis maleki (Khalil, 1961); Paradilepis urceina Bona, 1975; Paradilepis urceus (Wedl, 1855) Joyeux et Baer, 1950; Parvitaenia macrocoleo Bona, 1975; Parvitaenia macropeos (Wedl, 1855) Baer et Bona, 1960; Parvitaenia megascolecina Bona, 1975; Parvitaenia purpurea Johri, 1959; Parvitaenia samfyia Mettrick, 1967; Valipora ardeolae (Singh, 1952) Baer et Bona, 1960 and Valipora mutabilis (Linton, 1927). Known larval stages and adults from Africa are presented in review of species.
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Diversificação e evolução fenotípica em peixes cascudos (Siluriformes: Loricariidae: Loricariinae)Souza, Laura Barreto de Paula 22 February 2018 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / One of the major causes of the phylogenetic, temporal and spatial variation of species richness
is attributed to the processes of differential speciation and extinction of lineages, named
diversification. There is also a great phenotypic diversity among species that may be related to
diversification. The development of phylogenetic comparative methods allowed the study of
the diversification and evolution of species traits. The aim of this study is to investigate the
pattern of diversification and trait evolution of the suckermouth armored catfish, Loricariinae
subfamily, and to investigate if these attributes are related to the diversification rates within the
clade. We used a phylogeny containing 114 representatives of subfamily species and their
attributes body size, climatic niche and microhabitat (substrate) - position and width for both -
to evaluate the evolutionary rates and test the relationship between these different axes of the
species niche and their evolutionary rates. We estimated diversification rates with BAMM and
performed phylogenetic correlation analyzes (STRAPP) to address the question of whether the
attributes are related to the diversification process in the subfamily. We also performed analyzes
of disparity through time (DTT) to explore the temporal pattern of phenotypic evolution. The
diversification analysis showed that the subfamily had high rates of diversification. Body size
presented heterogeneous rates among clades, presenting a shift of diversification in which the
specie Paraloricaria agastor had the smallest size of the clade. Climatic niche position
presented a heterogeneous pattern of diversification rates, with a shift involving six species of
Rineloricaria that retained their niche position. Diversification of the climatic niche width
revealed the most heterogeneous pattern, presenting four shifts occurring in clades in which
some species possessed greater climatic niche widths. However, the rates of diversification of
both micro-habitat position and width did not show any shift. The STRAPP test revealed no
correlation between any of the traits studied with diversification, showing that evolutionary
process of Loricariinae seems to be independent of the phenotypic attributes investigated. The
DTT revealed that in most of the Loricariinae’s evolutionary history, the averages of disparity
of the studied attributes evolved under neutral evolution, although they presented peaks of
phenotypic disparity within the clades in the most recent time. The results showed that
Loricarinae evolved through a non-adaptive radiation where vicariant events would have
promoted allopatric speciation and the high diversification rates. In fact, it is known that the
radiation of Neotropical fishes was closely related to geological processes of basin formation
(hydrogeological hypothesis). DTTs analyzes reinforces this claim, because in most of the
evolutionary history the attributes evolved neutrally, without association with diversification,
as expected in non-adaptive radiation. Although the subfamily evolved under non-adaptive
radiation, divergent selection processes possibly occurred in species independently, promoting
significant disparity of attributes within the clades at the present time. The results obtained
highlights a peculiar evolutionary history for Loricariinae and a unique known example of nonadaptive
radiation for the Neotropics, which can be enlighten the understanding of the yet little
known processes that led to the extraordinary diversification of the Neotropical fishes. / Uma das causas da variação filogenética, temporal e espacial da riqueza das espécies são
atribuídas aos processos de especiação e extinção diferencial das linhagens, chamado de
diversificação. Existe também uma grande diversidade fenotípica entre as espécies que pode
estar relacionada à diversificação. O desenvolvimento de métodos filogenéticos comparativos
permitiu o estudo da diversificação e evolução de atributos das espécies. O objetivo do presente
estudo é investigar os padrões de diversificação e evolução de atributos de peixes Cascudos da
subfamília Loricariinae, e investigar se esses atributos estão correlacionados com as taxas de
diversificação. Foi utilizada uma filogenia contendo 114 representantes de espécies da
subfamília e os atributos tamanho corporal, posição e largura de nicho climático de microhábitat
(substrato), para avaliar as taxas evolutivas e relação entre esses diferentes eixos do
nicho das espécies e as taxas evolutivas da subfamília. As taxas de diversificação da subfamília
e dos atributos foram estimadas através do BAMM e foram realizadas análises de correlação
filogenética (STRAPP) a fim de detectar se os atributos estão moldando o processo de
diversificação na subfamília. Foram realizadas também análises de disparidade ao longo do
tempo (DTT) para explorar o padrão temporal de evolução fenotípica. A análise de
diversificação mostrou que a subfamília possui altas taxas de diversificação. O tamanho
corporal apresentou taxas heterogêneas entre os subclados, apresentando um shift de
diversificação no clado em que a espécie Paraloricaria agastor apresentou o menor tamanho
do clado. A posição de nicho climático apresentou um padrão heterogêneo de taxas de
diversificação, apresentando um shift envolvendo seis espécies de Rineloricaria que
conservaram sua posição de nicho. A diversificação da largura de nicho climático revelou o
padrão mais heterogêneo, apresentando quatro shifts que ocorreram em clados que contém
espécies com maiores larguras de nicho climático. Já as taxas de diversificação da posição e
largura de micro-hábitat não apresentaram shifts. Os testes STRAPP revelaram não haver
correlação entre nenhum dos atributos considerados no presente estudo e a diversificação,
mostrando que o processo evolutivo de Loricariinae parece ser independente dos atributos
fenotípicos investigados. O DTT revelou que na maior parte da história evolutiva da subfamília
as médias de disparidade dos atributos estudados evoluíram de forma neutra, porém
apresentaram picos de disparidade fenotípica dentro dos clados no tempo mais recente. Os
resultados mostram que provavelmente os Loricaríneos evoluíram através de uma radiação não
adaptativa onde eventos vicariantes teriam promovido especiação alopátrica e as altas taxas de
diversificação. De fato, acredita-se que a radiação dos peixes Neotropicais esteve intimamente
relacionada aos processos geológicos de formação de bacias (hipótese hidrogeológica). O DTT
reforça essa conclusão, pois em boa parte da história evolutiva os atributos evoluíram
neutramente, sem associação com a diversificação, como seria esperado em uma radiação não
adaptativa. Entretanto, apesar de a subfamília ter evoluído sob radiação não adaptativa,
processos de seleção divergente possivelmente ocorreram em espécies independentemente,
promovendo disparidade significativa dos atributos dentro dos clados no tempo presente. Os
resultados obtidos revelam uma história evolutiva peculiar para os Loricaríneos e um exemplo
raro de radiação não adaptativa nos Neotrópicos, que pode elucidar o entendimento dos
processos que levaram a extraordinária diversificação dos peixes Neotropicais, ainda pouco
conhecidos. / São Cristóvão, SE
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Relações filogenéticas das espécies do gênero Rineloricaria Bleeker, 1862 (Siluriformes, Loricariidae, Loricariinae) / Phylogenetic relationships of the species of the Rineloricaria Bleeker, 1862 (Siluriformes, Loricariidae, Loricariinae)Ilana Fichberg 17 December 2008 (has links)
As espécies do gênero Rineloricaria são representantes típicos da subfamília Loricariinae, família Loricariidae, tradicionalmente caracterizada pela presença de odontódios recobrindo o corpo, corpo fortemente deprimido e ausência de nadadeira adiposa. Rineloricaria compreende 65 espécies nominais, sendo o gênero mais rico em espécies na subfamília Loricariinae. Estudos filogenéticos prévios sobre Loricariidae não concordaram sobre a hipótese de monofiletismo e posicionamento filogenético de Rineloricaria entre outros Loricariinae. Os objetivos deste trabalho foram testar o monofiletismo do gênero e determinar seu posicionamento entre outros Loricariinae. Um estudo filogenético incluindo 36 espécies de Rineloricaria e 181 caracteres foi realizado utilizando parcimônia estrita. Os principais dados para análise foram derivados de morfologia esquelética e morfologia externa. O grupo externo incluiu uma quantidade representativa de gêneros considerados proximamente relacionados à Rineloricaria, sendo Neoplecostomus microps o táxon mais externo e ponto de enraizamento. Os resultados indicaram que Rineloricaria é monofilético e grupo-irmão dos outros Loricariinae. Doze sinapomorfias sustentam o monofiletismo de Rineloricaria. Dentre estas, uma sinapomorfia exclusiva é um processo dorso-mesial bem desenvolvido no quarto osso faringobranquial. Outras sinapomorfias não exclusivas para o gênero são: uma grande placa pré-anal trapezoidal circundada por três placas poligonais e caracteres específicos de dimorfismo sexual. / The species of Rineloricaria are typical members of Loricariinae subfamily, family Loricariidae, traditionally characterized by the presence of odontodes covering the body, strongly depressed body and absence of adipose fin. Rineloricaria comprises 65 nominal species and it is the most speciesrich genus in the subfamily Loricariinae. Previous phylogenetic studies on Loricariidae have not agreed on the putative monophyly and phylogenetic position of Rineloricaria among other Loricariinae. The objectives of this work were to test the monophyly of the genus and to determine its position among other Loricariinae. A phylogenetic study including 36 species of Rineloricaria and 181 characters was conducted using strict parsimony. The primary data for the analysis came from skeleton and external morphology. The outgroup included a number of representatives of genera previously considered as closely related to Rineloricaria, with Neoplecostomus microps as the most distant outgroup and rooting point. The results indicate that Rinolericaria is monophyletic and sister group to all other Loricariinae. Twelve sinapomorphies support the monophyly of Rineloricaria. Unique among them is the presence of a well-developed dorso-mesial process on the fourth pharyngobranchial bone. Other non-unique synapomorphies for the genus include: a great trapezoidal preanal plate surrounded by three polygonal plates and some specific dimorphic sexual features.
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