Masanori Kohda's research while affiliated with Osaka City University and other places

Publications (177)

Article
Cooperative breeding, a social system in which offspring receive care from other group members as well as their parents, occurs in insects, fish, birds and mammals. In this study, we report a new example of cooperative breeding in the cichlid fish (Neolamprologus bifasciatus). This species, endemic to Lake Tanganyika, Africa, inhabits rocky areas a...
Article
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An animal that tries to remove a mark from its body that is only visible when looking into a mirror displays the capacity for mirror self-recognition (MSR), which has been interpreted as evidence for self-awareness. Conservative interpretations of existing data conclude that convincing evidence for MSR is currently restricted to great apes. Here, w...
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Memorizing dominance relationships can help animals avoid unwinnable subsequent contests. However, when competitive ability changes over time—for example, as a function of condition—it may be adaptive to “forget” these dominance relationships and for subordinates to once again enter contests with previously dominant individuals. Here, we examined t...
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Kin selection plays a major role in the evolution of cooperative systems. However, many social species exhibit complex within-group relatedness structures, where kin selection alone cannot explain the occurrence of cooperative behaviour. Understanding such social structures is crucial to elucidate the evolution and maintenance of multi-layered coop...
Article
Siblings often compete for limited resources, such as food provided by their parents. However, although several functions of nonlethal sibling (nonsiblicidal) aggression have been proposed, there is currently little empirical evidence for these, apart from food monop-olization. Here, we investigated the functions of nonlethal sibling aggression in...
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Human society is cooperative and characterized by spontaneous prosociality. Comparative studies on endotherm vertebrates suggest that social interdependence causes the evolution of proactive prosociality. To test the generality of this hypothesis, we modify a prosocial choice task for application to the convict cichlid, Amatitlania nigrofasciata, a...
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Animals adjust their behaviors based on information from multiple sources; however, the brain can effectively process limited amounts of information. Therefore, attention is restricted to a small portion of environmental stimuli. When animals process multiple information inputs, focusing on information that is deemed important improves detection pr...
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Transitive inference (TI) is the ability to infer unknown relationships from previous information. To test TI in non-human animals, transitive responding has been examined in a TI task where non-adjacent pairs were presented after premise pair training. Some mammals, birds and paper wasps can pass TI tasks. Although previous studies showed that som...
Article
Sperm production is costly, and males are expected to strategically allocate this potentially limiting resource to maximize their fitness. Sperm allocation theory predicts that males should adjust their sperm expenditure in relation to female quality. However, the available empirical evidence is limited. In this study, we assessed whether wild male...
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Although parental care is known to occur in a wide range of teleost fishes, postnatal provisioning of nutrition has been documented rarely. Here, we describe a novel example of bi-parental care in a teleost, i.e. mucus-provisioning behaviour in the scale-eating cichlid Perissodus microlepis endemic to Lake Tanganyika. Field observations revealed th...
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“Face” is a special stimulus in humans and, nonhuman primates, and some other social mammals; that is, they perceive the face differently from the other body parts and other stimuli. In these species, the face conveys much information, so individuals examine the face at first sight rather than other body parts. Similar to mammals, the faces of fish...
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Siblings often compete for limited resources, particularly food provided by their parents. Such competition is usually nonviolent, but direct aggression has evolved in some species. However, there is little knowledge about sibling aggression in species without parental provisioning. Here, we investigated sibling aggression in the cichlid Neolamprol...
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Faces are the most important body part for differentiating among human individuals by humans. Humans read the face as a whole, rather than looking at its parts, which makes it more difficult to recognise inverted faces than upright. Some other mammals also identify each other based on the upright face and take longer to recognise inverted faces. Th...
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Editor’s note: This Short Report received both positive and negative reviews by experts. The Academic Editor has written an accompanying Primer that we are publishing alongside this article (https://doi.org/10.1371/journal.pbio.3000112). The linked Primer presents a complementary expert perspective; it discusses how the current study should be int...
Data
Supporting data. Excel spreadsheet containing behavioural observation data, including initial responses to the mirror, posturing, scraping, and control body mark data. (XLSX)
Data
Supplementary methods and results. Details of additional methods and results of control experiments. (DOCX)
Data
The frequency of scraping by a focal animal marked directly on the body. Frequency of scraping before marking (control), after transparent marking (sham), and colour marking (mark) over 3 h in the absence of a mirror. Sham and colour marks were on left flank, an area directly visible for fish (χ2 = 12.35, df = 2, n = 5, P < 0.002). (TIFF)
Data
Machine-learning tracking of wrasse interacting with a mirror. Preliminary example video of computational approaches to objectively quantify behaviour. (MOV)
Data
Upside-down swimming. The fish approaches the mirror while swimming upside-down. (MOV)
Data
Mouth fighting against the mirror reflection. The fish attacks the reflection with an open mouth in a common display of fish aggression. (MOV)
Data
Scraping of the face region. This behaviour was performed against the coral gravel substrate but was also performed against a rock. (MOV)
Data
Scraping of the throat. This behaviour was performed against the coral gravel substrate but was also performed against a rock. (MOV)
Article
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Scale-eating cichlid fishes, Perissodus spp., in Lake Tanganyika have laterally asymmetrical bodies, and each population is composed of righty and lefty morphs. Righty morphs attack the right side of prey and lefty morphs do the opposite. This anti-symmetric dimorphism has a genetic basis. Temporal changes in the frequencies of morphs in two cohabi...
Article
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...
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Background Seminal plasma proteins are associated with successful fertilization. However, their evolutionary correlation with fertilization mechanisms remains unclear. Cichlids from Lake Tanganyika show a variety-rich spawning behavior that is associated with the transfer of the sperm to the egg for fertilization. One of these behaviors, called “or...
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In cooperatively breeding animals, individuals other than breeders assist in raising young. While it is generally assumed that such helpers increase the reproductive success of breeders, positive effects can be cryptic and difficult to detect. Furthermore, measuring the effect of helpers in the wild is often difficult because multiple factors such...
Preprint
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The ability to perceive and recognise a reflected mirror image as self (mirror self-recognition, MSR) is considered a hallmark of cognition across species. Although MSR has been reported in mammals and birds, it is not known to occur in any other major taxon. A factor potentially limiting the ability to test for MSR is that the established assay fo...
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Many territorial animals reduce aggression toward their neighbors once territorial boundaries are established. This relationship is called the dear enemy phenomenon, hypothetically based on a conditional strategy like tit for tat (TFT). However, studies on territorial animals such as male songbirds do not fully support this hypothesis. We tested th...
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True individual recognition (TIR), the ability to distinguish multiple familiar members individually, is more elaborate than class-level recognition, and evidence for the ability to perform TIR is reported from primates, some other social mammals, birds and lizard in vertebrates. These animals exhibit a highly social structure, wherein TIR is essen...
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In cooperatively breeding or eusocial animals, increasing resources such as food is a major task of brood care helpers or workers. While such food acquisition has been shown in several animal taxa, evidence is absent in fishes. Here, we provide the first evidence of increased food abundance caused by helpers in a cooperatively breeding fish. Helper...
Article
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Parental investment affects the future survival and reproductive success of breeders. Therefore, breeders should optimize the amount of care they invest into the current offspring. In cooperative breeding systems, the amount of breeders' parental care is influenced by the behavior of brood-care helpers. Such workload adjustment is expected to depen...
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Since the pioneering work in chimpanzees, mirror self-recognition (MSR), the ability to recognise oneself in a mirror, has been reported in great apes, Asian elephants, dolphins, and some social birds using the mark test, in which animals that possess MSR touch an imperceptible mark on their own bodies only when a mirror is present. However, giant...
Article
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 t...
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The face is an important cue for discriminating conspecifics in some primates (including humans), other mammals and birds. Although there is considerable evidence that fish can discriminate between conspecifics based on familiarity, the actual traits used to do so remain unclear. However, recent studies showed that two cichlid species used face col...
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Animals in a population consistently differ from one another in behavioural types over time and this difference can affect intra- and interspecific relationships. However, empirical studies about roles of behavioural individual variation in interspecific interactions are scarce. Here, we provide evidence that inter-individual variation of a cichlid...
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Masquerade is a strategy whereby prey animals resemble environmental objects (e.g. twigs, bird droppings and stones) or inedible animals to avoid predatory attack. However, most studies of this strategy have been restricted to only a few animal groups. Therefore, novel examples are required to elucidate the diversity of masquerade strategies. Neola...
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The goby–shrimp symbiosis is a well-known example of mutualism among marine animals. It is generally accepted that the shrimp provides a sheltering burrow for the partner goby, and the goby warns its host about predatory risk. Other types of benefits between the participants are proposed, but most are based on anecdotal evidence. We propose the hyp...
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Delayed dispersal of offspring from the natal territory is an important process in the evolution of cooperative breeding. Ecological constraints such as habitat saturation can promote delayed dispersal. Thus far, the role of predation risk in the evolution of cooperative breeding systems has received less attention, although it is understood as an...
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A number of mammals and birds are known to be capable of visually discriminating between familiar and unfamiliar individuals, depending on facial patterns in some species. Many fish also visually recognize other conspecifics individually, and previous studies report that facial color patterns can be an initial signal for individual recognition. For...
Article
Despite competing for resources such as space, food and mates, many territorial animals are less aggressive towards neighbours who rarely go beyond their territorial boundaries. This so-called dear enemy phenomenon is advantageous in territorial defence, but it has not been well studied in fish. In this work, we tested the ‘correct–incorrect bounda...
Article
Extended phenotypes offer a unique opportunity to experimentally manipulate and identify sources of selection acting on traits under natural conditions. The social cichlid fish Neolamprologus multifasciatus builds nests by digging up aquatic snail shells, creating an extended sexual phenotype that is highly amenable to experimental manipulation thr...