1
|
Takeuchi Y. Developmental Process of a Pronounced Laterality in the Scale-eating Cichlid Fish Perissodus microlepis in Lake Tanganyika. Zoolog Sci 2023; 40:160-167. [PMID: 37042695 DOI: 10.2108/zs220078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/19/2023] [Indexed: 04/09/2023]
Abstract
Lateral preference in behaviors has been widely documented in many vertebrates and invertebrates. Such preferences are strange, puzzling, and on the surface, not adaptive. However, behavioral laterality may increase an individual's fitness as well as foraging accuracy and speed. There is little experimental evidence regarding the developmental process of laterality, and unsolved questions have perplexed researchers for several decades. Related to these issues, here, I review that the scale-eating cichlid Perissodus microlepis found in Lake Tanganyika is a valuable model to address the developmental mechanism of animal laterality. The scale-eating cichlid has pronounced behavioral laterality and uses its asymmetric mouth during feeding events. Recent studies have shown that behavioral laterality in this fish depends on both genetic factors and past experience. The attack-side preference of scale eaters is an acquired trait in an early developmental stage. Juvenile fish empirically learn which side of the prey is more effective for tearing scales and gradually select the dominant side for attacking. However, the superior kinetics of body flexion during the dominant side attack has innate characteristics. Additionally, left-right differences in scale-eater mandibles also develop during ontogeny. Further progress toward understanding the comprehensive mechanisms of laterality should address the following persistent barriers: (1) the effects of phylogenetic constraints and ecological factors on the level of laterality; and (2) the neuronal and molecular mechanisms that produce left-right behavioral differences.
Collapse
Affiliation(s)
- Yuichi Takeuchi
- Department of Anatomy and Neuroscience, Faculty of Medicine, University of Toyama, Sugitani, Toyama 434-7207, Japan
| |
Collapse
|
2
|
Indermaur A, Theis A, Egger B, Salzburger W. Mouth dimorphism in scale‐eating cichlid fish from Lake Tanganyika advances individual fitness. Evolution 2018; 72:1962-1969. [DOI: 10.1111/evo.13552] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 07/04/2018] [Indexed: 01/25/2023]
Affiliation(s)
- Adrian Indermaur
- Zoological Institute University of Basel Vesalgasse 1 4051 Basel Switzerland
| | - Anya Theis
- Zoological Institute University of Basel Vesalgasse 1 4051 Basel Switzerland
| | - Bernd Egger
- Zoological Institute University of Basel Vesalgasse 1 4051 Basel Switzerland
| | - Walter Salzburger
- Zoological Institute University of Basel Vesalgasse 1 4051 Basel Switzerland
| |
Collapse
|
3
|
Raffini F, Fruciano C, Meyer A. Gene(s) and individual feeding behavior: Exploring eco-evolutionary dynamics underlying left-right asymmetry in the scale-eating cichlid fish Perissodus microlepis. Ecol Evol 2018; 8:5495-5507. [PMID: 29938068 PMCID: PMC6010907 DOI: 10.1002/ece3.4070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 03/22/2018] [Accepted: 03/26/2018] [Indexed: 01/09/2023] Open
Abstract
The scale‐eating cichlid fish Perissodus microlepis is a textbook example of bilateral asymmetry due to its left or right‐bending heads and of negative frequency‐dependent selection, which is proposed to maintain this stable polymorphism. The mechanisms that underlie this asymmetry remain elusive. Several studies had initially postulated a simple genetic basis for this trait, but this explanation has been questioned, particularly by reports observing a unimodal distribution of mouth shapes. We hypothesize that this unimodal distribution might be due to a combination of genetic and phenotypically plastic components. Here, we expanded on previous work by investigating a formerly identified candidate SNP associated to mouth laterality, documenting inter‐individual variation in feeding preference using stable isotope analyses, and testing their association with mouth asymmetry. Our results suggest that this polymorphism is influenced by both a polygenic basis and inter‐individual non‐genetic variation, possibly due to feeding experience, individual specialization, and intraspecific competition. We introduce a hypothesis potentially explaining the simultaneous maintenance of left, right, asymmetric and symmetric mouth phenotypes due to the interaction between diverse eco‐evolutionary dynamics including niche construction and balancing selection. Future studies will have to further tease apart the relative contribution of genetic and environmental factors and their interactions in an integrated fashion.
Collapse
Affiliation(s)
- Francesca Raffini
- Lehrstuhl für Zoologie und Evolutionsbiologie Department of Biology University of Konstanz Konstanz Germany.,International Max Planck Research School (IMPRS) for Organismal Biology University of Konstanz Konstanz Germany
| | - Carmelo Fruciano
- Lehrstuhl für Zoologie und Evolutionsbiologie Department of Biology University of Konstanz Konstanz Germany.,School of Earth, Environmental & Biological Sciences Queensland University of Technology Brisbane QLD Australia.,Institut de biologie de l'Ecole normale supérieure (IBENS) Ecole normale supérieure, CNRS, INSERM PSL Université, Paris France
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie Department of Biology University of Konstanz Konstanz Germany.,International Max Planck Research School (IMPRS) for Organismal Biology University of Konstanz Konstanz Germany.,Radcliffe Institute for Advanced Study Harvard University Cambridge Massachusetts
| |
Collapse
|
4
|
Raffini F, Fruciano C, Meyer A. Morphological and genetic correlates in the left–right asymmetric scale-eating cichlid fish of Lake Tanganyika. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Francesca Raffini
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse, Konstanz, Germany
- International Max Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, Konstanz, Germany
| | - Carmelo Fruciano
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse, Konstanz, Germany
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstrasse, Konstanz, Germany
- International Max Planck Research School (IMPRS) for Organismal Biology, University of Konstanz, Konstanz, Germany
- Radcliffe Institute for Advance Study, Harvard University, Cambridge, MA, USA
| |
Collapse
|
5
|
Lee HJ, Schneider RF, Manousaki T, Kang JH, Lein E, Franchini P, Meyer A. Lateralized Feeding Behavior is Associated with Asymmetrical Neuroanatomy and Lateralized Gene Expressions in the Brain in Scale-Eating Cichlid Fish. Genome Biol Evol 2017; 9:3122-3136. [PMID: 29069363 PMCID: PMC5737854 DOI: 10.1093/gbe/evx218] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2017] [Indexed: 12/20/2022] Open
Abstract
Lateralized behavior ("handedness") is unusual, but consistently found across diverse animal lineages, including humans. It is thought to reflect brain anatomical and/or functional asymmetries, but its neuro-molecular mechanisms remain largely unknown. Lake Tanganyika scale-eating cichlid fish, Perissodus microlepis show pronounced asymmetry in their jaw morphology as well as handedness in feeding behavior-biting scales preferentially only from one or the other side of their victims. This makes them an ideal model in which to investigate potential laterality in neuroanatomy and transcription in the brain in relation to behavioral handedness. After determining behavioral handedness in P. microlepis (preferred attack side), we estimated the volume of the hemispheres of brain regions and captured their gene expression profiles. Our analyses revealed that the degree of behavioral handedness is mirrored at the level of neuroanatomical asymmetry, particularly in the tectum opticum. Transcriptome analyses showed that different brain regions (tectum opticum, telencephalon, hypothalamus, and cerebellum) display distinct expression patterns, potentially reflecting their developmental interrelationships. For numerous genes in each brain region, their extent of expression differences between hemispheres was found to be correlated with the degree of behavioral lateralization. Interestingly, the tectum opticum and telencephalon showed divergent biases on the direction of up- or down-regulation of the laterality candidate genes (e.g., grm2) in the hemispheres, highlighting the connection of handedness with gene expression profiles and the different roles of these brain regions. Hence, handedness in predation behavior may be caused by asymmetric size of brain hemispheres and also by lateralized gene expressions in the brain.
Collapse
Affiliation(s)
- Hyuk Je Lee
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
- Present address: Molecular Ecology and Evolution Laboratory, Department of Biological Science, Sangji University, Wonju, Korea
| | - Ralf F Schneider
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
| | - Tereza Manousaki
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
- Present address: Hellenic Centre for Marine Research (HCMR), Institute of Marine Biology, Biotechnology, and Aquaculture (IMBBC), Heraklion, Greece
| | - Ji Hyoun Kang
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
- Present address: Korean Entomological Institute, Korea University, Seoul, Korea
| | - Etienne Lein
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
- Present address: Department of Collective Behaviour, Max Planck Institute for Ornithology and University of Konstanz, Konstanz, Germany
| | - Paolo Franchini
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
| | - Axel Meyer
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
| |
Collapse
|
6
|
Raffini F, Fruciano C, Franchini P, Meyer A. Towards understanding the genetic basis of mouth asymmetry in the scale-eating cichlidPerissodus microlepis. Mol Ecol 2016; 26:77-91. [DOI: 10.1111/mec.13699] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/29/2016] [Accepted: 05/09/2016] [Indexed: 12/16/2022]
Affiliation(s)
- Francesca Raffini
- Lehrstuhl für Zoologie und Evolutionsbiologie; Department of Biology; University of Konstanz; Universitätsstrasse 10 78464 Konstanz Germany
- International Max Planck Research School (IMPRS) for Organismal Biology; Max-Planck-Institut für Ornithologie; Am Obstberg 1 78315 Radolfzell Germany
| | - Carmelo Fruciano
- Lehrstuhl für Zoologie und Evolutionsbiologie; Department of Biology; University of Konstanz; Universitätsstrasse 10 78464 Konstanz Germany
| | - Paolo Franchini
- Lehrstuhl für Zoologie und Evolutionsbiologie; Department of Biology; University of Konstanz; Universitätsstrasse 10 78464 Konstanz Germany
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie; Department of Biology; University of Konstanz; Universitätsstrasse 10 78464 Konstanz Germany
- International Max Planck Research School (IMPRS) for Organismal Biology; Max-Planck-Institut für Ornithologie; Am Obstberg 1 78315 Radolfzell Germany
| |
Collapse
|
7
|
Hedrick PW, Smith DW, Stahler DR. Negative-assortative mating for color in wolves. Evolution 2016; 70:757-66. [PMID: 26988852 DOI: 10.1111/evo.12906] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/13/2016] [Accepted: 03/01/2016] [Indexed: 12/01/2022]
Abstract
There is strong negative-assortative mating for gray and black pelage color in the iconic wolves in Yellowstone National Park. This is the first documented case of significant negative-assortative mating in mammals and one of only a very few cases in vertebrates. Of 261 matings documented from 1995 to 2015, 63.6% were between gray and black wolves and the correlation between mates for color was -0.266. There was a similar excess of matings of both gray males × black females and black males × gray females. Using the observed frequency of negative-assortative mating in a model with both random and negative-assortative mating, the estimated proportion of negative-assortative mating was 0.430. The estimated frequency of black wolves in the population from 1996 to 2014 was 0.452 and these frequencies appear stable over this 19-year period. Using the estimated level of negative-assortative mating, the predicted equilibrium frequency of the dominant allele was 0.278, very close to the mean value of 0.253 observed. In addition, the patterns of genotype frequencies, that is, the observed proportion of black homozygotes and the observed excess of black heterozygotes, are consistent with negative-assortative mating. Importantly these results demonstrate that negative-assortative mating could be entirely responsible for the maintenance of this well-known color polymorphism.
Collapse
Affiliation(s)
- Philip W Hedrick
- School of Life Sciences, Arizona State University, Tempe, Arizona, 85287.
| | - Douglas W Smith
- Yellowstone Wolf Project, Yellowstone Center for Resources, Yellowstone National Park, Wyoming, 82190
| | - Daniel R Stahler
- Yellowstone Wolf Project, Yellowstone Center for Resources, Yellowstone National Park, Wyoming, 82190
| |
Collapse
|
8
|
Lee HJ, Heim V, Meyer A. Genetic evidence for prevalence of alloparental care in a socially monogamous biparental cichlid fish, Perissodus microlepis, from Lake Tanganyika supports the "selfish shepherd effect" hypothesis. Ecol Evol 2016; 6:2843-53. [PMID: 27217943 PMCID: PMC4863010 DOI: 10.1002/ece3.2089] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 02/02/2016] [Accepted: 03/03/2016] [Indexed: 01/09/2023] Open
Abstract
Alloparental care – care for unrelated young – is rare in animals, and its ecological or evolutionary advantages or, alternative maladaptive nature, remain unclear. We investigate alloparental care in the socially monogamous cichlid fish Perissodus microlepis from Lake Tanganyika that exhibits bi‐parental care. In a genetic parentage analysis, we discovered a surprisingly high percentage of alloparental care represented by brood mixing, extra‐pair paternity and extra‐pair maternity in all broods that we investigated. The percentage of nondescendant juveniles of other parents, i.e., brood mixing, ranged from 5% to 57% (mean = 28%). The distribution of genetic parentage also suggests that this socially monogamous species has, in fact, polygamous mating system. The prevalence of genetically mixed broods can be best explained by two, not mutually exclusive hypotheses on farming‐out and fostering behaviors. In the majority of broods, the sizes of the parents’ own (descendant) offspring were significantly larger than those of the adopted (nondescendant) juveniles, supporting the ‘selfish shepherd effect’ hypothesis, i.e., that foster parents preferentially accept unrelated “smaller or not larger” young since this would tend to lower the predation risks for their own larger offspring. There was also a tendency for larger parents particularly mothers, more so than smaller parents, to care predominantly for their own offspring. Larger parents might be better at defending against cuckoldry and having foreign young dumped into their broods through farming‐out behavior. This result might argue for maladaptive effects of allopatric care for the foster parents that only larger and possibly more experienced pairs can guard against. It needs to be determined why, apparently, the ability to recognize one's own young has not evolved in this species.
Collapse
Affiliation(s)
- Hyuk Je Lee
- Chair in Zoology and Evolutionary Biology Department of Biology University of Konstanz 78457 Konstanz Germany; Department of Biological Science College of Science and Engineering Sangji University Wonju 220-702 Korea
| | - Valentin Heim
- Chair in Zoology and Evolutionary Biology Department of Biology University of Konstanz 78457 Konstanz Germany
| | - Axel Meyer
- Chair in Zoology and Evolutionary Biology Department of Biology University of Konstanz 78457 Konstanz Germany
| |
Collapse
|
9
|
Takeuchi Y, Hori M, Tada S, Oda Y. Acquisition of Lateralized Predation Behavior Associated with Development of Mouth Asymmetry in a Lake Tanganyika Scale-Eating Cichlid Fish. PLoS One 2016; 11:e0147476. [PMID: 26808293 PMCID: PMC4726545 DOI: 10.1371/journal.pone.0147476] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/05/2016] [Indexed: 01/08/2023] Open
Abstract
The scale-eating cichlid Perissodus microlepis with asymmetric mouth is an attractive model of behavioral laterality: each adult tears off scales from prey fishes' left or right flanks according to the direction in which its mouth is skewed. To investigate the development of behavioral laterality and mouth asymmetry, we analyzed stomach contents and lower jaw-bone asymmetry of various-sized P. microlepis (22 ≤ SL<115 mm) sampled in Lake Tanganyika. The shapes of the pored scales found in each specimen's stomach indicated its attack side preference. Early-juvenile specimens (SL<45 mm) feeding mainly on zooplankton exhibited slight but significant mouth asymmetry. As the fish acquired scale-eating (45 mm ≤ SL), attack side preference was gradually strengthened, as was mouth asymmetry. Among size-matched individuals, those with more skewed mouths ate more scales. These findings show that behavioral laterality in scale-eating P. microlepis is established in association with development of mouth asymmetry which precedes the behavioral acquisition, and that this synergistic interaction between physical and behavioral literalities may contribute to efficient scale-eating.
Collapse
Affiliation(s)
- Yuichi Takeuchi
- Department of Anatomy, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Graduate School of Science, Nagoya University, Aichi, Japan
- * E-mail:
| | - Michio Hori
- Department of Biological Science, Kyoto University, Kyoto, Japan
| | - Shinya Tada
- Graduate School of Science and Engineering, Ehime University, Ehime, Japan
| | - Yoichi Oda
- Graduate School of Science, Nagoya University, Aichi, Japan
| |
Collapse
|
10
|
Lee HJ, Heim V, Meyer A. Genetic and environmental effects on the morphological asymmetry in the scale-eating cichlid fish, Perissodus microlepis. Ecol Evol 2015; 5:4277-86. [PMID: 26664678 PMCID: PMC4667837 DOI: 10.1002/ece3.1691] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 08/12/2015] [Indexed: 11/09/2022] Open
Abstract
The scale-eating cichlid fish, Perissodus microlepis, from Lake Tanganyika are a well-known example of an asymmetry dimorphism because the mouth/head is either left-bending or right-bending. However, how strongly its pronounced morphological laterality is affected by genetic and environmental factors remains unclear. Using quantitative assessments of mouth asymmetry, we investigated its origin by estimating narrow-sense heritability (h (2) ) using midparent-offspring regression. The heritability estimates [field estimate: h (2) = 0.22 ± 0.06, P = 0.013; laboratory estimate: h (2) = 0.18 ± 0.05, P = 0.004] suggest that although variation in laterality has some additive genetic component, it is strongly environmentally influenced. Family-level association analyses of a putative microsatellite marker that was claimed to be linked to gene(s) for laterality revealed no association of this locus with laterality. Moreover, the observed phenotype frequencies in offspring from parents of different phenotype combinations were not consistent with a previously suggested single-locus two-allele model, but they neither were able to reject with confidence a random asymmetry model. These results reconcile the disputed mechanisms for this textbook case of mouth asymmetry where both genetic and environmental factors contribute to this remarkable case of morphological asymmetry.
Collapse
Affiliation(s)
- Hyuk Je Lee
- Lehrstuhl für Zoologie und Evolutionsbiologie Department of Biology University of Konstanz 78457 Konstanz Germany ; Department of Biological Science College of Science and Engineering Sangji University Wonju 220-702 Korea
| | - Valentin Heim
- Lehrstuhl für Zoologie und Evolutionsbiologie Department of Biology University of Konstanz 78457 Konstanz Germany
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie Department of Biology University of Konstanz 78457 Konstanz Germany
| |
Collapse
|
11
|
Hulsey CD, García-De León FJ, Meyer A. Sexual dimorphism in a trophically polymorphic cichlid fish? J Morphol 2015; 276:1448-54. [DOI: 10.1002/jmor.20433] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/30/2015] [Accepted: 08/03/2015] [Indexed: 11/10/2022]
Affiliation(s)
| | - Francisco J. García-De León
- Laboratorio De Genética Para La Conservación; Centro De Investigaciones Biológicas Del Noroeste, Instituto Politécnico Nacional 195; La Paz, B.C.S. 23096 Mexico
| | - Axel Meyer
- Department of Biology; University of Konstanz; Konstanz 78457 Germany
| |
Collapse
|
12
|
Hata H, Hori M. Inheritance patterns of morphological laterality in mouth opening of zebrafish,Danio rerio. Laterality 2012; 17:741-54. [DOI: 10.1080/1357650x.2011.626563] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
13
|
Kusche H, Lee HJ, Meyer A. Mouth asymmetry in the textbook example of scale-eating cichlid fish is not a discrete dimorphism after all. Proc Biol Sci 2012; 279:4715-23. [PMID: 23055070 DOI: 10.1098/rspb.2012.2082] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Individuals of the scale-eating cichlid fish, Perissodus microlepis, from Lake Tanganyika tend to have remarkably asymmetric heads that are either left-bending or right-bending. The 'left' morph opens its mouth markedly towards the left and preferentially feeds on the scales from the right-hand side of its victim fish, and the 'right' morph bites scales from the victims' left-hand side. This striking dimorphism made these fish a textbook example of their astonishing degree of ecological specialization and as one of the few known incidences of negative frequency-dependent selection acting on an asymmetric morphological trait, where left and right forms are equally frequent within a species. We investigated the degree and the shape of the frequency distribution of head asymmetry in P. microlepis to test whether the variation conforms to a discrete dimorphism, as generally assumed. In both adult and juvenile fish, mouth asymmetry appeared to be continuously and unimodally distributed with no clear evidence for a discrete dimorphism. Mixture analyses did not reveal evidence of a discrete or even strong dimorphism. These results raise doubts about previous claims, as reported in textbooks, that head variation in P. microlepis represents a discrete dimorphism of left- and right-bending forms. Based on extensive field sampling that excluded ambiguous (i.e. symmetric or weakly asymmetric) individual adults, we found that left and right morphs occur in equal abundance in five populations. Moreover, mate pairing for 51 wild-caught pairs was random with regard to head laterality, calling into question reports that this laterality is maintained through disassortative mating.
Collapse
Affiliation(s)
- Henrik Kusche
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | | | | |
Collapse
|
14
|
Lee HJ, Kusche H, Meyer A. Handed foraging behavior in scale-eating cichlid fish: its potential role in shaping morphological asymmetry. PLoS One 2012; 7:e44670. [PMID: 22970282 PMCID: PMC3435272 DOI: 10.1371/journal.pone.0044670] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 08/10/2012] [Indexed: 12/02/2022] Open
Abstract
Scale-eating cichlid fish, Perissodus microlepis, from Lake Tanganyika display handed (lateralized) foraging behavior, where an asymmetric ‘left’ mouth morph preferentially feeds on the scales of the right side of its victim fish and a ‘right’ morph bites the scales of the left side. This species has therefore become a textbook example of the astonishing degree of ecological specialization and negative frequency-dependent selection. We investigated the strength of handedness of foraging behavior as well as its interaction with morphological mouth laterality in P. microlepis. In wild-caught adult fish we found that mouth laterality is, as expected, a strong predictor of their preferred attack orientation. Also laboratory-reared juvenile fish exhibited a strong laterality in behavioral preference to feed on scales, even at an early age, although the initial level of mouth asymmetry appeared to be small. This suggests that pronounced mouth asymmetry is not a prerequisite for handed foraging behavior in juvenile scale-eating cichlid fish and might suggest that behavioral preference to attack a particular side of the prey plays a role in facilitating morphological asymmetry of this species.
Collapse
Affiliation(s)
- Hyuk Je Lee
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Konstanz, Germany
- Zukunftskolleg, University of Konstanz, Konstanz, Germany
| | - Henrik Kusche
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Konstanz, Germany
- International Max Planck Research School for Organismal Biology, University of Konstanz, Konstanz, Germany
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Konstanz, Germany
- International Max Planck Research School for Organismal Biology, University of Konstanz, Konstanz, Germany
- Graduate School in Chemical Biology, University of Konstanz, Konstanz, Germany
- * E-mail:
| |
Collapse
|
15
|
Martin RA, Pfennig DW. Widespread disruptive selection in the wild is associated with intense resource competition. BMC Evol Biol 2012; 12:136. [PMID: 22857143 PMCID: PMC3432600 DOI: 10.1186/1471-2148-12-136] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 07/19/2012] [Indexed: 02/07/2023] Open
Abstract
Background Disruptive selection has been documented in a growing number of natural populations. Yet, its prevalence within individual systems remains unclear. Furthermore, few studies have sought to identify the ecological factors that promote disruptive selection in the wild. To address these issues, we surveyed 15 populations of Mexican spadefoot toad tadpoles, Spea multiplicata, and measured the prevalence of disruptive selection acting on resource-use phenotypes. We also evaluated the relationship between the strength of disruptive selection and the intensity of intraspecific competition—an ecological agent hypothesized to be an important driver of disruptive selection. Results Disruptive selection was the predominant mode of quadratic selection across all populations. However, a directional component of selection favoring an extreme ecomorph—a distinctive carnivore morph—was also common. Disruptive selection was strongest in populations experiencing the most intense intraspecific competition, whereas stabilizing selection was only found in populations experiencing relatively weak intraspecific competition. Conclusions Disruptive selection can be common in natural populations. Intraspecific competition for resources may be a key driver of such selection.
Collapse
Affiliation(s)
- Ryan A Martin
- Department of Biology, CB#3280, University of North Carolina, Chapel Hill, NC 27599, USA.
| | | |
Collapse
|
16
|
Lateralized kinematics of predation behavior in a Lake Tanganyika scale-eating cichlid fish. PLoS One 2012; 7:e29272. [PMID: 22238598 PMCID: PMC3253053 DOI: 10.1371/journal.pone.0029272] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/23/2011] [Indexed: 12/03/2022] Open
Abstract
Behavioral lateralization has been documented in many vertebrates. The scale-eating cichlid fish Perissodus microlepis is well known for exhibiting lateral dimorphism in its mouth morphology and lateralized behavior in robbing scales from prey fish. A previous field study indicated that this mouth asymmetry closely correlates with the side on which prey is attacked, but details of this species' predation behavior have not been previously analyzed because of the rapidity of the movements. Here, we studied scale-eating behavior in cichlids in a tank through high-speed video monitoring and quantitative assessment of behavioral laterality and kinematics. The fish observed showed a clear bias toward striking on one side, which closely correlated with their asymmetric mouth morphologies. Furthermore, the maximum angular velocity and amplitude of body flexion were significantly larger during attacks on the preferred side compared to those on the nonpreferred side, permitting increased predation success. In contrast, no such lateral difference in movement elements was observed in acoustically evoked flexion during the escape response, which is similar to flexion during scale eating and suggests that they share a common motor control pathway. Thus the neuronal circuits controlling body flexion during scale eating may be functionally lateralized upstream of this common motor pathway.
Collapse
|
17
|
Hata H, Yasugi M, Hori M. Jaw laterality and related handedness in the hunting behavior of a scale-eating characin, Exodon paradoxus. PLoS One 2011; 6:e29349. [PMID: 22216256 PMCID: PMC3247259 DOI: 10.1371/journal.pone.0029349] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2011] [Accepted: 11/27/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Asymmetry in animal bodies and behavior has evolved several times, but our knowledge of their linkage is limited. Tanganyikan scale-eating cichlids have well-known antisymmetry in their bodies and behavior; individuals open their mouths leftward (righty) or rightward (lefty), and righties always attack the right flank of the prey, whereas lefties attack the left. This study analyzed the morphological asymmetry in a scale-eating characiform, Exodon paradoxus, and its behavioral handedness. METHODOLOGY/PRINCIPAL FINDINGS Each eight E. paradoxus was observed for 1-h with a prey goldfish in an aquarium to detect the behavioral handedness. Following the experiment, the lateral differences in the mandibles and head-inclination of these eight and ten additional specimens were analyzed. Both measurements on the morphology showed a bimodal distribution, and the laterality identified by these two methods was always consistent within a given individual, indicating that the characin has morphological antisymmetry. Furthermore, this laterality significantly corresponded to behavioral handedness; that is, lefties more often rasped scales from the right flank of the prey and vice versa. However, the correlation between laterality and handedness is the opposite of that in the cichlids. This is due to differences in the feeding apparatus and technique. The characin has cuspids pointing forward on the external side of the premaxilla, and it thrusts its dominant body side outward from its body axis on the flank of the prey to tear off scales. By contrast, the cichlids draw their dominant body side inward toward the axis or rotate it to scrape or wrench off scales with the teeth lined in the opened mouth. CONCLUSIONS/SIGNIFICANCE This study demonstrated that the antisymmetry in external morphology and the corresponding behavioral handedness have evolved in two lineages of scale-eating fishes independently, and these fishes adopt different utilization of their body asymmetry to tear off scales.
Collapse
Affiliation(s)
- Hiroki Hata
- Graduate School of Science and Technology, Ehime University, Matsuyama, Ehime, Japan.
| | | | | |
Collapse
|
18
|
Abstract
Two recent studies in BMC Biology and Evolution raise important questions about a textbook case of frequency-dependent selection in scale-eating cichlid fishes. They also suggest a fascinating new line of research testing the effects of handed behavior on morphological asymmetry. See research article http://www.biomedcentral.com/1741-7007/8/8.
Collapse
|