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1.
Mol Phylogenet Evol ; 167: 107355, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34774762

RESUMO

The origin and diversification process of lineages of organisms that are currently widely distributed among continents is an interesting subject for exploring the evolutionary history of global species diversity. Ground beetles of the subfamily Carabinae are flightless except for one lineage, but nevertheless occur on all continents except Antarctica. Here, we used sequence data from ultraconserved elements to reconstruct the phylogeny, divergence time, biogeographical history, ancestral state of hind wings and changes in the speciation rate of Carabinae. Our results show that Carabinae originated in the Americas and diversified into four tribes during the period from the late Jurassic to the late Cretaceous, with two in South America (Celoglossini) and Australasia (Pamborini) and two in Laurasia (Cychrini and Carabini). The ancestral Carabinae were inferred to be winged; three of four tribes (Cychrini, Ceglossini and Pamborini) have completely lost their hind wings and flight capability. The remaining tribe, Carabini, diverged into the subtribes Carabina (wingless) and Calosomina (winged) in the Oligocene. Carabina originated in Europe, spread over Eurasia and diversified into approximately 1000 species, accounting for around 60% of all Carabinae species. Calosomina that were flight-capable dispersed from North America or Eurasia to South America, Australia, and Africa, and then flightless lineages evolved on oceanic islands and continental highlands. The speciation rate increased in the Cychrini and Carabini clades in Eurasia. Within Carabini, the speciation rate was higher for wingless than winged states. Our study showed that the global distribution of Carabinae resulted from ancient dispersal before the breakup of Gondwana and more recent dispersal through flight around the world. These patterns consequently illustrate the causal relationships of geographical history, evolution of flightlessness, and the global distribution and species diversity of Carabinae.


Assuntos
Besouros , Animais , Besouros/genética , Geografia , América do Norte , Filogenia , Filogeografia , Asas de Animais
2.
Zoolog Sci ; 39(6): 545-553, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36495489

RESUMO

Predator-prey interactions based on laterality have recently been observed between fishes and their prey populations. Maintenance of antisymmetric dimorphism by frequency-dependent selection has been reported in fish, but has not been observed in invertebrates. Over 10 years, we investigated long-term changes in the "ratio of laterality" (frequency of righty morphs in a population) in the cuttlefish Sepia recurvirostra and its potential prey prawns Penaeus semisulcatus and Metapenaeus endeavouri in the Visayan Sea, the Philippines. The morphological laterality of cuttlefish and prey prawns was defined by measuring the asymmetry of the cuttlebone and carapace, respectively. Cuttlefish and prey prawns showed morphological antisymmetry, being composed with righty morphs and lefty morphs. The ratio of laterality of cuttlefish and one prey prawn oscillated significantly, but the oscillation was not strongly synchronized. The ratio of laterality of cuttlefish followed that of the prey prawn, indicating that predation biased to each laterality occurred in relation to their laterality. These results suggest that the lateral dimorphism of cuttlefish is maintained through frequency-dependent selection on lateral morphs of the predator cuttlefish and prey prawns. Our findings provide new insight into the ecological significance and antisymmetry maintenance mechanism in relation to interspecific interactions in marine invertebrates.


Assuntos
Decápodes , Sepia , Animais , Decapodiformes , Lateralidade Funcional , Peixes/anatomia & histologia , Comportamento Predatório
3.
Zoolog Sci ; 38(3): 231-237, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34057347

RESUMO

A Japanese piscivorous chub, "hasu" (Opsariichthys uncirostris), and its main prey, "ayu" (Plecoglossus altivelis), both have laterally asymmetric bodies, similar to other fishes; each population consists of righty morphs and lefty morphs. This antisymmetric dimorphism has a genetic basis. Temporal changes in the ratios of laterality (i.e., frequency of righty morphs in a population) of these predator and prey fish species were investigated for a 20-year period at a pelagic site in the southwestern area of Lake Biwa, Japan. The dimorphism of each species was maintained dynamically throughout the period, and the ratio of laterality was found to change periodically in a semi-synchronized manner. Direct inspection of the relationship between the ratios of laterality of the two species indicated that the ratio of ayu followed that of hasu, suggesting that the predator-prey interaction was responsible for the semi-synchronized change. Stomach contents analysis of each hasu revealed that cross-predation, in which righty predators catch lefty prey and lefty predators catch righty prey, occurred more frequently than the reverse combination (parallel-predation). This differential predation is presumed to cause frequency-dependent selection on the two morphs of the predator and prey, and to drive semi-synchronized changes in the laterality of the two species. Some discussion pertaining to the atypical form of the semi-synchronized change in laterality found in this study is presented from the viewpoint of predator-prey interaction in fishes.


Assuntos
Peixes/fisiologia , Lateralidade Funcional , Comportamento Predatório/fisiologia , Animais , Lagos , Especificidade da Espécie , Fatores de Tempo
4.
Zoolog Sci ; 36(2): 147-153, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31120650

RESUMO

Many cichlid species in the shallow-shore of Lake Tanganyika suffer damage from attacks by the scale-eater Perissodus microlepis. Many prey fish engage in warning behaviors to this predator. It has been hypothesized that, if prey fish have difficulty employing such behavioral tactics, morphological defenses against scale-eating, such as hard scales, will evolve. The shrimp-eating cichlids, Altolamprologus compressiceps (Ac) and Neolamprologus fasciatus (Nf), exhibit hunting behaviors in which they remain motionless for up to 10 seconds while aiming at prey, when they are vulnerable to scale-eating predators; thus, these fish have likely evolved morphological defenses against "scale-attacks". We tested this hypothesis in Ac and Nf, as well as three other predatory fish, Lamprologus callipterus, Lepidiolamprologus elongatus and Lep. attenuatus, that are not motionless for such a long time. Under natural conditions, Ac and Nf were rarely attacked, while the other three species were attacked frequently. When freshly killed specimens of these five species were displayed underwater in the presence of P. microlepis, Ac was rarely attacked, while Nf and the three other species were attacked frequently. Among the five fish species, the force required to tear off scales was highest for Ac, and this force was negatively correlated with the frequency of attacks on the displayed fish. These results support the hypothesis that the hard scales of Ac function as an anti-scale-attack measure, although it remains unclear why free-swimming Nf were rarely attacked while aiming at prey, despite the fact that the force required to tear off its scales was not large.


Assuntos
Escamas de Animais/anatomia & histologia , Ciclídeos/fisiologia , Comportamento Predatório/fisiologia , Animais , Ciclídeos/anatomia & histologia , Ingestão de Alimentos , Zâmbia
5.
Zoolog Sci ; 34(4): 267-274, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28770681

RESUMO

Laterality has been studied in several vertebrates, mainly in terms of brain lateralization and behavioral laterality, but morphological asymmetry has not been extensively investigated. Asymmetry in fishes was first described in scale-eating cichlids from Lake Tanganyika, in the form of bilateral dimorphism in which some individuals, when opening their mouths, twist them to the right and others to the left. This asymmetry has a genetic basis, and is correlated with lateralized attack behaviors. This has subsequently been found in fishes from numerous taxa with various feeding habits. The generality of such morphological laterality should thus be investigated in as wide a range of fishes as possible. Using specific indicators of lateral differences in mandibles and head inclination, we find that representative species from all 60 orders of extant gnathostome fishes (both bony and cartilaginous) possess morphological laterality. Furthermore, we identify the same laterality in agnathans (hagfish and lamprey), suggesting that this trait appeared early in fish evolution and has been maintained across fish lineages. However, a comparison of asymmetry among groups of bony fishes reveals, unexpectedly, that phylogenetically more recent-groups possess less asymmetry in body structures. The universality of laterality in fishes indicates a monophyletic origin, and may have been present in the ancestors of vertebrates. Ecological factors, predator-prey interactions in particular, may be key drivers in the evolution and maintenance of dimorphism, and may also be responsible for the cryptic trend of asymmetry in derived groups. Because lungfish and coelacanths share this trait, it is likely that tetrapods also inherited it. We believe that study of this morphological laterality will provide insights into the behavioral and sensory lateralization of vertebrates.


Assuntos
Peixes/anatomia & histologia , Peixes/fisiologia , Lateralidade Funcional/fisiologia , Animais , Peixes/genética , Filogenia , Especificidade da Espécie
6.
Mol Phylogenet Evol ; 95: 1-10, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26578441

RESUMO

We investigated the phylogenetic relationships among tiger beetles of the subtribe Cicindelina (=Cicindela s. lat.; Coleoptera: Cicindelidae) mainly from the Oriental and Sino-Japanese zoogeographic regions using one mitochondrial and three nuclear gene sequences to examine the position of the subgenus Sophiodela, currently classified in the genus Cicindela s. str., their biogeography, and the evolution of their brilliant coloration. The subgenus Sophiodela was not related to the other subgenera of Cicindela s. str. but was closely related to the genus Cosmodela. In addition, the Oriental genus Calochroa was polyphyletic with three lineages, one of which was closely related to Sophiodela and Cosmodela. The clade comprising Sophiodela, Cosmodela and two Calochroa species, referred to here as the Sophiodela group, was strongly supported, and most species in this clade had similar brilliant coloration. The Sophiodela group was related to the genera Calomera, Cicindela (excluding Sophiodela) and Cicindelidia, and these were related to Lophyra, Hipparidium and Calochroa, except species in the Sophiodela group. Divergence time estimation suggested that these worldwide Cicindelina groups diverged in the early Oligocene, and the Sophiodela group, which is found in the Oriental and Sino-Japanese zoogeographic regions, in the mid Miocene. Some components of the elytral pattern related to maculation and coloration in the Cicindelina taxa studied contained weak, but significant, phylogenetic signals and were partly associated with habitat types. Therefore, the brilliant coloration of the Sophiodela was related to both phylogeny and habitat adaptation, although the function of coloration needs to be studied.


Assuntos
Besouros/classificação , Evolução Molecular , Filogeografia , Pigmentação/genética , Animais , Besouros/anatomia & histologia , Besouros/genética , Cor , Ecossistema , Especiação Genética , Filogenia
7.
BMC Biol ; 12: 90, 2014 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-25359595

RESUMO

BACKGROUND: Lake Tanganyika, an ancient lake in the Great Rift Valley, is famous for the adaptive radiation of cichlids. Five tribes of the Cichlidae family have acquired herbivory, with five ecomorphs: grazers, browsers, scrapers, biters and scoopers. Sixteen species of the herbivorous cichlids coexist on a rocky littoral slope in the lake. Seven of them individually defend feeding territories against intruding herbivores to establish algal farms. We collected epiphyton from these territories at various depths and also gathered fish specimens. Algal and cyanobacteria community structures were analysed using the amplicon-metagenomic method. RESULTS: Based on 454-pyrosequencing of SSU rRNA gene sequences, we identified 300 phototrophic taxa, including 197 cyanobacteria, 57 bacillariophytes, and 31 chlorophytes. Algal farms differed significantly in their composition among cichlid species, even in the same ecomorph, due in part to their habitat-depth segregation. The algal species composition of the stomach contents and algal farms of each species differed, suggesting that cichlids selectively harvest their farms. The stomach contents were highly diverse, even between species in the same tribe, in the same feeding ecomorph. CONCLUSIONS: In this study, the amplicon-metagenomic approach revealed food niche separation based on habitat-depth segregation among coexisting herbivorous cichlids in the same ecomorphs in Lake Tanganyika.


Assuntos
Ciclídeos/classificação , Dieta/veterinária , Animais , Comportamento Animal , Cianobactérias/classificação , Cianobactérias/isolamento & purificação , Diatomáceas/classificação , Diatomáceas/isolamento & purificação , Ecossistema , Conteúdo Gastrointestinal/microbiologia , Lagos , Metagenômica , Tanzânia
8.
Zoolog Sci ; 30(8): 613-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23915153

RESUMO

Many animals show lateral bias in various behaviors. In fish, behavioral laterality has been studied from the perspective of its relation with brain lateralization. On the other hands, in some fishes, head dimorphism (righty or lefty) corresponds to behavioral laterality, such as foraging behavior. To examine the correlation between morphological asymmetry and behavioral laterality associated with brain lateralization, we conducted two behavioral tests (the detour test and fast-start test) using a poeciliid fish, Girardinus metallicus. In both behavioral tests, some individuals tended to move rightward, while others tended to move leftward, in a manner associated with head incline. In the detour-test, righty individuals primarily detoured leftward, whereas lefty individuals primarily detoured rightward. In the fast-start tests, the reverse tendency was seen; righty individuals tended to escape rightward, whereas lefty individuals tended to escape leftward. Such results indicate that brain lateralization may be also associated with morphological asymmetry.


Assuntos
Comportamento Animal/fisiologia , Lateralidade Funcional/fisiologia , Fundulidae/fisiologia , Animais , Padronização Corporal , Natação
9.
Mol Biol Evol ; 28(6): 1769-76, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21172834

RESUMO

Reverse evolution is a widespread phenomenon in biology, but the genetic mechanism for the reversal of a genetic change for adaptation to the ancestral state is not known. Here, we report the first case of complete reverse evolution of two amino acids, serine and alanine, at a single position in RH1 opsin pigment for adaptation to water depth. We determined RH1 sequences of cichlid fishes from four tribes of Lake Tanganyika with different habitat depths. Most of the species were divided into two types: RH1 with 292A for species in shallow water or 292S for species in deep water. Both types were adapted to their ambient light environments as indicated by the absorption spectra of the RH1 pigments. Based on the RH1 locus tree and ecological data, we inferred the ancestral amino acids at position 292 and the distribution of the depth ranges (shallow or deep) of ancestral species of each tribe. According to these estimates, we identified two distinct parallel adaptive evolutions: The replacement A292S occurred at least four times for adaptation from shallow to deep water, and the opposite replacement S292A occurred three times for adaptation from deep to shallow water. The latter parallelism represents the complete reverse evolution from the derived to the ancestral state, following back adaptive mutation with reversal of the RH1 pigment function accompanied by reversal of the species habitat shift.


Assuntos
Adaptação Fisiológica/genética , Evolução Biológica , Ciclídeos/classificação , Ciclídeos/genética , Opsinas/genética , Alelos , Sequência de Aminoácidos , Substituição de Aminoácidos/genética , Animais , Sequência de Bases , Água Doce , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Tanzânia
10.
J Exp Biol ; 215(Pt 14): 2390-8, 2012 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-22723477

RESUMO

Vertebrates show left-right biases in turning direction, limb usage, predator-escape response and use of sensory organs. In particular, some fishes are known to have lateral biases in predatory behaviors corresponding to their morphological antisymmetry. To reveal the effects of these laterally biased behaviors on predator-prey interaction, we conducted behavioral tests of predatory events between largemouth bass, Micropterus salmoides, and freshwater gobies, Rhinogobius sp., both of which have individuals with a well-developed left side and individuals with a well-developed right side. The left-developed bass tended to approach the goby clockwise from behind, whereas right-developed individuals tended to approach counterclockwise. Congruently, left-developed gobies began their escape maneuvers at a longer distance from bass when they were approached clockwise than when they were approached counterclockwise, whereas right-developed gobies showed the reverse tendency. The longer the distance between bass and gobies at the start of goby escape, the more the subsequent bass strike or dash was delayed. Under these conditions, predation should be more successful when a left (right)-developed bass meets a right (left)-developed goby, and less successful when a left (right)-developed bass meets a left (right)-developed goby. This prediction was consistent with the difference in predation success in our test and in field data from Lake Biwa, Japan. We conclude that lateral biases in the behavioral direction of each morphological type will generate bias in predation success between different combinations of predator and prey types, leading to the maintenance of antisymmetric dimorphism through negative frequency-dependent natural selection.


Assuntos
Bass/anatomia & histologia , Bass/fisiologia , Lateralidade Funcional/fisiologia , Perciformes/anatomia & histologia , Perciformes/fisiologia , Comportamento Predatório/fisiologia , Animais , Reação de Fuga/fisiologia , Japão , Modelos Biológicos
11.
Biol Lett ; 8(3): 355-7, 2012 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-22114323

RESUMO

A focus on pair bonds between males and females is fundamental to study the evolution of social organization. Because pair bonds are generally identified from direct observations of pairs that maintain physical proximity, pair bonds may have been overlooked in animals that do not exhibit such visible pairs. The Lake Tanganyika cichlid fish Xenotilapia rotundiventralis forms schools that consist of mouthbrooding and non-brooding adults in mid-water, and visible pairs are not recognized. A previous study suggested that mouthbrooding females transfer fractions of the young to males when the young become large. However, it remains a mystery whether the mating pairs maintain pair bonds so that the females can transfer the young to their mates. To answer this question, we conducted a parentage analysis using 10 microsatellite markers. The analysis showed that the mouthbrooding adults were most likely genetic fathers and mothers of the young in their mouths. This finding suggests that the female-to-male shift of young takes place between mating partners, and thus the mating pairs maintain pair bonds at least until the shift of young. The present study is the first to detect pair bonds in animals in which physical proximity has not been observed.


Assuntos
Ciclídeos/fisiologia , Repetições de Microssatélites , Ligação do Par , Reprodução , Animais , Ciclídeos/genética , Feminino , Marcadores Genéticos , Masculino , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Zâmbia
12.
Naturwissenschaften ; 99(1): 23-31, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22089034

RESUMO

To determine whether the appearance of a reproductively parasitic tactic varies, and how this variation affects territorial males of the Lake Tanganyika cichlid fish Telmatochromis vittatus, we examined the reproductive ecology of territorial males in Mtondwe and compared it with that of a neighboring Wonzye population, where nest density differs from that at Mtondwe. In Wonzye, with high nest density, male tactics change with their body size from a territorial to a non-territorial parasitic tactic called piracy in which they conquer several nests defended by territorial males and take over the nests while females are spawning. These "pirate" males could decrease the costs incurred by travelling among nests by exclusively targeting aggregations of nests in close proximity while avoiding separate nests. Territorial males in Wonzye sacrifice the potential higher attractiveness offered by large nests and instead compete for nests farther from neighbors on which pirates less frequently intrude. In contrast, the Mtondwe population had lower nest density and piracy was absent. Given that the success of piracy depends on the close proximity of nests, nest density is likely responsible for the observed variation in the occurrence of piracy between the two populations. Furthermore, in Mtondwe, territorial males competed for larger nests and were smaller than the territorial males in Wonzye. Thus, this lower nest density may free territorial males from the selection pressures for increased size caused by both defense against nest piracy and the need to develop into pirates as they grow.


Assuntos
Ciclídeos/fisiologia , Comportamento de Nidação/fisiologia , Reprodução/fisiologia , Animais , Feminino , Masculino , Densidade Demográfica , Razão de Masculinidade
13.
Zoolog Sci ; 29(5): 286-92, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22559961

RESUMO

Behavioral laterality is widely found among vertebrates, but has been little studied in aquatic invertebrates. We examined behavioral laterality in attacks on prey shrimp by the cuttlefish, Sepia lycidas, and correlated this to their morphological asymmetry. Behavioral tests in the laboratory revealed significant individual bias for turning either clockwise or counterclockwise toward prey, suggesting behavioral dimorphism in foraging behavior. Morphological bias was examined by measuring the curvature of the cuttlebone; in some the cuttlebone was convex to the right (righty), while in others, the cuttlebone was convex to the left (lefty). The frequency distributions of an index of cuttlebone asymmetry were bimodal, indicating that populations were composed of two types of individuals: "righty" and "lefty." Moreover, an individual's laterality in foraging behavior corresponded with the asymmetry of its cuttlebone, with righty individuals tending to turn counterclockwise and lefty ones in the opposite direction. These results indicate that cuttlefish exhibit behavioral dimorphism and morphological antisymmetry in natural populations. The presence of two types of lateral morph in cuttlefish provides new information on the relationship between antisymmetric morphologies and the evolution of individual laterality in behavioral responses in cephalopods. The implications of these findings for the interpretation of ecological meaning and maintenance mechanisms of laterality in cuttlefish are also discussed.


Assuntos
Comportamento Animal/fisiologia , Lateralidade Funcional/fisiologia , Sepia/anatomia & histologia , Sepia/fisiologia , Animais
14.
Zoolog Sci ; 29(1): 49-53, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22233496

RESUMO

The asymmetry of mouth morphology, in which the mouth opens either leftward or rightward, is a unique example of antisymmetry that is widely found in fishes, such as Tanganyikan scale-eating cichlids, herbivorous cichlids, and the Japanese freshwater goby. This dimorphism is thought to be heritable in a Mendelian manner similar to that of the dominance of the lefty allele over righty, with homozygotes of lefty alleles being absent. This study aims to reveal whether this trait is inherited in the same Mendelian manner in fishes other than those examined to date, and whether the absence of the dominant homozygote is due to a lethal effect. We conducted F(1) and F(2) breeding experiments using the Tanganyikan cichlid Julidochromis transcriptus and Japanese medaka Oryzias latipes. For both J. transcriptus and O. latipes, the F(1) generations produced by incrossing lefty parents showed a lefty:righty ratio of 2:1, whereas incrosses of righties produced only righty offspring. Test crosses between lefty and righty produced a 1:1 ratio of lefty and righty offspring. These results are consistent with the inheritance model in which righty is homozygous for a recessive righty allele and lefty is heterozygous for dominant lefty and recessive righty alleles, in agreement with previous observations. The F(2) test cross also confirmed this pattern. Furthermore, no lethal effects on hatchability of O. latipes were detected, refuting the suggestion that the dominant homozygote is embryonic lethal. We conclude that mouth laterality is inherited in the same Mendelian manner in these two species, similar to that other fish species studied previously. However, the reason for absence of the dominant homozygote remains unclear.


Assuntos
Padronização Corporal/genética , Ciclídeos/genética , Ciclídeos/fisiologia , Oryzias/genética , Oryzias/fisiologia , Alelos , Animais , Padronização Corporal/fisiologia , Fertilização , Endogamia , Boca/anatomia & histologia , Óvulo/fisiologia
15.
Laterality ; 17(6): 741-54, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23098202

RESUMO

The inheritance patterns of asymmetry in mouth opening in zebrafish were investigated using crossing experiments. Zebrafish exhibit asymmetric laterality in mouth opening, with each individual having either a leftward (righty) or rightward (lefty) bias. All righty incrosses produced only righty F(1), whereas all lefty incrosses resulted in an F(1) L:R ratio of 2:1. All test crosses between lefty and righty individuals resulted in an F(1) L:R=1:1. These results were consistent with the hereditary pattern for Japanese medaka, three Tanganyikan cichlids, and a Japanese riverine goby. The pattern suggests a one-locus two-allele Mendelian model of inheritance, with the lefty allele being dominant over righty and the dominant homozygote being lethal. To determine the reason for the absence of lefty homozygotes, the survival rates of the offspring were examined according to developmental stage. Survival did not differ among combinations of parent laterality. Thus the mechanism underlying the lethality of the dominant homozygote remains unclear. This study showed that the mouth-opening laterality of zebrafish is genetically determined and that the direction follows a Mendelian inheritance pattern that is shared among cypriniform zebrafish, beloniform medaka, perciform cichlids, and a goby, suggesting a common genetic background in mouth-opening laterality among these species.


Assuntos
Lateralidade Funcional/genética , Lateralidade Funcional/fisiologia , Boca/anatomia & histologia , Boca/fisiologia , Peixe-Zebra/fisiologia , Alelos , Análise de Variância , Anestesia , Animais , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Cognição/fisiologia , Cruzamentos Genéticos , Feminino , Masculino , Sobrevida/fisiologia , Visão Binocular
16.
Naturwissenschaften ; 98(10): 837-43, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21850467

RESUMO

Alternative reproductive tactics are widespread in males and may cause intraspecific differences in testes investment. Parker's sneak-guard model predicts that sneaker males, who mate under sperm competition risk, invest in testes relatively more than bourgeois conspecifics that have lower risk. Given that sneakers are much smaller than bourgeois males, sneakers may increase testes investment to overcome their limited sperm productivity because of their small body sizes. In this study, we examined the mechanism that mediates differential testes investment across tactics in the Lake Tanganyika cichlid fish Lamprologus callipterus. In the Rumonge population of Burundi, bourgeois males are small compared with those in other populations and have a body size close to sneaky dwarf males. Therefore, if differences in relative testis investment depend on sperm competition, the rank order of relative testis investment should be dwarf males > bourgeois males in Rumonge = bourgeois males in the other populations. If differences in relative testis investment depend on body size, the rank order of relative testes investment should be dwarf males > bourgeois males in Rumonge > bourgeois males in the other populations. Comparisons of relative testis investment among the three male groups supported the role of sperm competition, as predicted by the sneak-guard model. Nevertheless, the effects of absolute body size on testes investment should be considered to understand the mechanisms underlying intraspecific variation in testes investment caused by alternative reproductive tactics.


Assuntos
Tamanho Corporal , Ciclídeos/anatomia & histologia , Ciclídeos/fisiologia , Modelos Biológicos , Comportamento Sexual Animal/fisiologia , Testículo/anatomia & histologia , Animais , Feminino , Masculino , Reprodução/fisiologia
17.
Zoolog Sci ; 28(12): 869-74, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22132783

RESUMO

The predator-prey relationship between largemouth bass, Micropterus salmoides, and freshwater goby, Rhinogobius spp., in Lake Biwa, Japan, was examined with respect to their morphological antisymmetry (laterality). Largemouth bass and Rhinogobius gobies exhibited lateral dimorphism in the height of the mandible and the length of the dentary, respectively. Populations of both species were composed of both left-developed and right-developed individuals. Each predation event was categorized as either cross-predation (a predator caught prey of the opposite morph) or parallel-predation (a predator caught prey of the same morph). Stomach contents analysis revealed that cross-predation events predominated over parallel-predation. Annual sampling for eight years demonstrated that in both largemouth bass and Rhinogobius gobies, the ratio of right-developed individuals in the population fluctuated temporally around 0.5. As the predominance of cross-predation was found in the relationship between the exotic largemouth bass and an endemic goby, the predominance may be caused by a kinematical interplay at each predation event.


Assuntos
Perciformes/fisiologia , Comportamento Predatório/fisiologia , Animais , Ecossistema , Água Doce , Japão , Fatores de Tempo
18.
Zootaxa ; 4790(2): zootaxa.4790.2.4, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-33055841

RESUMO

Pogonostoma (Pogonostoma) natsuae sp. nov. from southwestern Madagascar is described as new to science. The new species is compared to similar Pogonostoma (Pogonostoma) meridionale Fleutiaux, 1899, which occurs in the southernmost areas of Madagascar and whose elaborated redescription is presented. Both species are illustrated in colour photographs of their habitus and diagnostic characters of the type and other specimens.


Assuntos
Besouros , Distribuição Animal , Animais , Cor , Madagáscar
19.
Proc Biol Sci ; 276(1676): 4207-14, 2009 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-19726479

RESUMO

Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result.


Assuntos
Ciclídeos/fisiologia , Comportamento Competitivo/fisiologia , Comportamento de Nidação/fisiologia , Comportamento Sexual Animal/fisiologia , Comportamento Espacial/fisiologia , Análise de Variância , Animais , Tamanho Corporal , Feminino , Masculino
20.
Zootaxa ; 4661(2): zootaxa.4661.2.3, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31716709

RESUMO

All members of Sophiodela Nakane 1955, hitherto a subgenus of Cicindela Linnaeus, 1758, are reviewed based on the structure of the everted internal sac of the male genitalia. In addition, many species of other genera and subgenera such as the genera Cosmodela Rivalier, 1961, Calochroa Hope, 1838, and Cicindela and its subgenus Pancallia Rivalier, 1961, are also reviewed regarding their reproductive structures. Their relationships are discussed using a comparison between morphological and molecular analyses. Through this study, the taxonomic rank of Sophiodela is raised from a subgenus to a genus as it is demonstrated to be a distinct monophyletic group by both the morphological and molecular analyses. Amongst the species of Sophiodela, S. cyanea Fabricius, 1787 is changed to the subgenus Pancallia. We conclude that the everted internal sac is a useful tool for grouping the genera and subgenera and can be used as a taxonomic character.


Assuntos
Besouros , Animais , Genitália Masculina , Masculino , Filogenia
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