Hiroki Hata - Profile on Academia.edu (original) (raw)

Papers by Hiroki Hata

Molecular phylogeny of obligate fish parasites of the family Cymothoidae (Isopoda, Crustacea): evolution of the attachment mode to host fish and the habitat shift from saline water to freshwater

Marine Biology

Species-diverse coral communities on an artificial substrate at a tuna farm in Amami, Japan

Marine Environmental Research, Apr 30, 2013

Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the ... more Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the natural environment. In Japan, tuna-farming is conducted on coral reefs that have been damaged by mass-bleaching events and crown-of-thorns starfish (COTS) outbreaks. This study focused on the coral community on an artificial substrate of tuna-farm to reveal the possible effects of tuna-farming on the natural environment. Corals flourished on ropes suspended in the farm in the Amami Islands, southern Japan. These were moored 3 m below the sea-surface in 50-m-deep water. The coral community on the rope was analyzed and compared with those on natural substrata on two adjacent COTS-damaged reefs and with that in a protected reef. Corals were monitored throughout a year. Sixty coral species grew on the ropes, that corresponds to 27.3% of the 220 species known from Amami. The coral community was unique, dominated by massive faviid corals. On the ropes, the water temperature rarely exceeded 30.0 °C and no corals on the rope were severely bleached or covered by sedimentation during the observations. The tuna-farm infrastructure provided corals with a suitable habitat, and species-rich coral communities were established. These coral communities are an important node connecting tuna-farms and the natural environment.

Journal of Experimental Marine Biology and Ecology, Nov 1, 2002

We compared the community structure of benthic algae inside and outside pomacentrid damselfish (S... more We compared the community structure of benthic algae inside and outside pomacentrid damselfish (Stegastes nigricans) territories in a moat at Sesoko Island, Okinawa, Japan. S. nigricans maintained ''algae farms'' that were dominated by the filamentous rhodophyte, Womersleyella setacea. Species richness and biomass were higher inside damselfish territories than outside, while species diversity and evenness were higher outside. Detrended correspondence analysis (DCA) based on species composition showed that the dominance of W. setacea was maintained throughout the year in all samples collected from inside damselfish territories. The observed strong dominance of filamentous rhodophytes was consistent with the findings of most studies on damselfish territories worldwide. However, the dominance of a single species of alga and low species diversity inside the territories was in contrast to the findings of previous studies, in which the reduction of grazing pressure caused intermediate disturbance and enhanced algal species diversity. This discrepancy in algal species diversity inside the damselfish territories seems to have been caused by unique characteristics of the alga and the fish. W. setacea traps sediment, which reduces the availability of firm substrata for attachment and inhibits the recruitment of some algae. Moreover, S. nigricans ''weeds'' indigestible calcareous and thicker algae. The algal assemblage outside damselfish territories varied among samples, and included mat-forming cyanophytes (Calothrix aeruginosa and Calothrix codicola), a prostrate laminar phaeophyte (Padina sp.), thin and small-scaled algae (Cladophora sp. and Feldmannia indica), finely branched filamentous rhodophytes (Taenioma perpusillum and Herposiphonia obscura), and a coarsely branched rhodophyte (Gelidiopsis variabilis).

BMC biology, Jan 29, 2014

BackgroundLake Tanganyika, an ancient lake in the Great Rift Valley, is famous for the adaptive r... more BackgroundLake 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.ResultsBased 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 composi...

Species-diverse coral communities on an artificial substrate at a tuna farm in Amami, Japan

Marine Environmental Research, 2013

Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the ... more Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the natural environment. In Japan, tuna-farming is conducted on coral reefs that have been damaged by mass-bleaching events and crown-of-thorns starfish (COTS) outbreaks. This study focused on the coral community on an artificial substrate of tuna-farm to reveal the possible effects of tuna-farming on the natural environment. Corals flourished on ropes suspended in the farm in the Amami Islands, southern Japan. These were moored 3 m below the sea-surface in 50-m-deep water. The coral community on the rope was analyzed and compared with those on natural substrata on two adjacent COTS-damaged reefs and with that in a protected reef. Corals were monitored throughout a year. Sixty coral species grew on the ropes, that corresponds to 27.3% of the 220 species known from Amami. The coral community was unique, dominated by massive faviid corals. On the ropes, the water temperature rarely exceeded 30.0 °C and no corals on the rope were severely bleached or covered by sedimentation during the observations. The tuna-farm infrastructure provided corals with a suitable habitat, and species-rich coral communities were established. These coral communities are an important node connecting tuna-farms and the natural environment.

Advantage of harmlessness in gaining preferential access to a heterospecific territory

Journal of Fish Biology, 2007

ABSTRACT Underwater observations conducted in the shallow waters of the southern part of Lake Tan... more ABSTRACT Underwater observations conducted in the shallow waters of the southern part of Lake Tanganyika showed that a zoobenthos-eating cichlid Neolamprologus mustax preferentially foraged in the permanent territory of an algivorous cichlid Neolamprologus moorii, even though other zoobenthos-eaters were chased out. Benthic invertebrates were much richer within the territory of N. moorii than outside, suggesting that the territory was an attractive feeding ground for zoobenthos-eaters. Stomach contents analysis showed that N. mustax rarely ate fish broods, although other zoobenthos-eaters often did so. It is concluded that the differential tolerance of N. moorii towards zoobenthos-eaters based on their harmfulness to broods benefits harmless N. mustax by allowing its use of the prey-rich territory.

Journal of Experimental Marine Biology and Ecology, 2002

We compared the community structure of benthic algae inside and outside pomacentrid damselfish (S... more We compared the community structure of benthic algae inside and outside pomacentrid damselfish (Stegastes nigricans) territories in a moat at Sesoko Island, Okinawa, Japan. S. nigricans maintained ''algae farms'' that were dominated by the filamentous rhodophyte, Womersleyella setacea. Species richness and biomass were higher inside damselfish territories than outside, while species diversity and evenness were higher outside. Detrended correspondence analysis (DCA) based on species composition showed that the dominance of W. setacea was maintained throughout the year in all samples collected from inside damselfish territories. The observed strong dominance of filamentous rhodophytes was consistent with the findings of most studies on damselfish territories worldwide. However, the dominance of a single species of alga and low species diversity inside the territories was in contrast to the findings of previous studies, in which the reduction of grazing pressure caused intermediate disturbance and enhanced algal species diversity. This discrepancy in algal species diversity inside the damselfish territories seems to have been caused by unique characteristics of the alga and the fish. W. setacea traps sediment, which reduces the availability of firm substrata for attachment and inhibits the recruitment of some algae. Moreover, S. nigricans ''weeds'' indigestible calcareous and thicker algae. The algal assemblage outside damselfish territories varied among samples, and included mat-forming cyanophytes (Calothrix aeruginosa and Calothrix codicola), a prostrate laminar phaeophyte (Padina sp.), thin and small-scaled algae (Cladophora sp. and Feldmannia indica), finely branched filamentous rhodophytes (Taenioma perpusillum and Herposiphonia obscura), and a coarsely branched rhodophyte (Gelidiopsis variabilis).

Ecological Research, 2011

The territorial damselfish, Stegastes nigricans, maintains algal farms by excluding invading herb... more The territorial damselfish, Stegastes nigricans, maintains algal farms by excluding invading herbivores and weeding unpalatable algae from its territories. In Okinawa, Japan, S. nigricans farms are exclusively dominated by Polysiphonia sp., a highly digestible filamentous rhodophyte. This study was aimed at determining the diet of S. nigricans in Okinawa and its dependency on these almost-monoculture algal farms based on stomach contents and chemical analyses. Stomach content analyses revealed that all available food items in the algal farms (i.e., algae, benthic animal inhabitants, trapped detritus) were contained in fish stomachs, but amorphous organic matter accounted for 68% of the contents. Therefore, carbon and nitrogen stable isotope ratios and fatty acid (FA) compositions were analyzed to trace items actually assimilated in their bodies. Stable isotope analyses showed that benthic animals were an important food source even for this farmer fish. Two essential FAs (EFA), 20:4n6 and 20:5n3, which are produced only by rhodophytes among available food items, were rich in the muscle tissue of S. nigricans as well as in algal mats and detritus, suggesting that algal mats contribute EFAs to S. nigricans directly and indirectly through the food web. In conclusion, S. nigricans ingested algal mats, detritus and benthic animals maintained within its farm. Algae and detritus were original sources of EFAs, and benthic animals, which were much more abundant in the farms than in outside territories, provided a nitrogen-rich dietary source for the fish.

Biology Letters, 2006

In cultivation mutualisms, farming animals prepare fields for cultivars, enhance their growth and... more In cultivation mutualisms, farming animals prepare fields for cultivars, enhance their growth and harvest them. For example, in terrestrial ecosystems, plant–herbivore cultivation mutualisms arose between humans and their crops only relatively recently. We discovered an obligate cultivation mutualism between a damselfish and an alga in a coral reef ecosystem. The damselfish, Stegastes nigricans , manages algal farms through territorial defence against the invading grazers and through weeding of unpalatable algae. As a result, the algal farms of S. nigricans are dominated by one species, Polysiphonia sp. We performed an exhaustive survey of algal assemblages inside and outside the territories of five damselfish species around the Ryukyu Islands, Japan, using molecular and morphological characteristics. Polysiphonia sp. 1 grew exclusively inside the farms of S. nigricans , and never elsewhere. Since only Polysiphonia sp. 1 is harvested and consumed by the damselfish as a staple food, ...

by Ian Donohue, Franziska Schädelin, Kevin Schneider, Jacco van Rijssel, Romulus Abila, Diogo Antunes, Taylor Banda, Auguste Chocha Manda, Peter Akoll, Karoline Fritzsche, Hugo F. Gante, M Genner, Hiroki Hata, Joachim Frommen, Arne Jungwirth, Luc Janssens de Bisthoven, Prince Kaleme, Stephan Koblmüller, Anton Lamboj, Pascal Masilya, Loïc Kéver, Ad Konings, Gaspard Ntakimazi, W. Okello, Lobomir Pialek, Pierre Denis Plisnier, Jelena Rajkov, Joost A M Raeymaekers, Isa Schoen, Pooja Singh, George Turner, Alexandra Tyers, Alexandra A - T Weber, Holger Zimmermann, Ola Svensson, and Maarten Vanhove

Inheritance patterns of morphological laterality in mouth opening of zebrafish, Danio rerio

Laterality, 2012

Inheritance Patterns of Lateral Dimorphism Examined through Breeding Experiments in Tanganyikan Cichlid (Julidochromis transcriptus) and Japanese Medaka ( …

Zoological science, 2012

Demise of monocultural algal farms by exclusion of territorial damselfish

Marine Ecology-progress Series, 2003

BMC Evolutionary Biology, 2010

Background: On coral reefs, damselfish defend their territories from invading herbivores and main... more Background: On coral reefs, damselfish defend their territories from invading herbivores and maintain algal turfs, from which they harvest filamentous algae. In southern Japan, intensive weeding of indigestible algae by Stegastes nigricans results in overgrowth by one filamentous alga, Polysiphonia sp. 1. Because this alga is highly susceptible to grazing and is competitively inferior to other algae, it survives only within the protective territories of this fish species, suggesting an obligate mutualism between damselfish and their cultivated alga. The wide distribution of damselfish species through the Indo-Central Pacific raises the question of whether this species-specific mutualism is maintained throughout the geographic range of the fish. To address this question, from all 18 damselfish species we conducted comprehensive surveys of algal flora within their territories throughout the Indo-West Pacific, and identified species of Polysiphonia using morphological examination and gene sequencing data.

Monoculture and mixed-species algal farms on a coral reef are maintained through intensive and extensive management by damselfishes

Journal of experimental marine biology and ecology, 2004

Marine Ecology-progress Series, 2002

Resident herbivorous damselfishes (Pisces: Pomacentridae) exclude other herbivores from their ter... more Resident herbivorous damselfishes (Pisces: Pomacentridae) exclude other herbivores from their territories and reduce the grazing pressure within these territories. Among the damselfish, Stegastes nigricans is unique in that it manages a virtual monoculture dominated by the erect filamentous rhodophyte Womersleyella setacea, whereas many other herbivorous damselfishes maintain species-rich farms. We observed the behavior of S. nigricans in a lagoon in Okinawa, Japan, and discovered that this species intensively weeded out specific algae. To analyze weeding selectivity, we compared the algae picked up and discarded by S. nigricans to the algal assemblage found inside the territory. To examine the digestibility of each algal species, 10 damselfish were collected, and algae removed from their stomachs were compared with those found in the intestine and faeces. Inside their territories, S. nigricans selectively weeded out indigestible algae. These algae were latecolonizing species, and the intensive weeding suppressed algal growth beyond early successional stages. Consequently, selective weeding enabled the fish to maintain virtual monocultural farms of a digestible early colonizer, W. setacea, inside their territories.

Molecular phylogeny of obligate fish parasites of the family Cymothoidae (Isopoda, Crustacea): evolution of the attachment mode to host fish and the habitat shift from saline water to freshwater

Marine Biology

Species-diverse coral communities on an artificial substrate at a tuna farm in Amami, Japan

Marine Environmental Research, Apr 30, 2013

Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the ... more Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the natural environment. In Japan, tuna-farming is conducted on coral reefs that have been damaged by mass-bleaching events and crown-of-thorns starfish (COTS) outbreaks. This study focused on the coral community on an artificial substrate of tuna-farm to reveal the possible effects of tuna-farming on the natural environment. Corals flourished on ropes suspended in the farm in the Amami Islands, southern Japan. These were moored 3 m below the sea-surface in 50-m-deep water. The coral community on the rope was analyzed and compared with those on natural substrata on two adjacent COTS-damaged reefs and with that in a protected reef. Corals were monitored throughout a year. Sixty coral species grew on the ropes, that corresponds to 27.3% of the 220 species known from Amami. The coral community was unique, dominated by massive faviid corals. On the ropes, the water temperature rarely exceeded 30.0 °C and no corals on the rope were severely bleached or covered by sedimentation during the observations. The tuna-farm infrastructure provided corals with a suitable habitat, and species-rich coral communities were established. These coral communities are an important node connecting tuna-farms and the natural environment.

Journal of Experimental Marine Biology and Ecology, Nov 1, 2002

We compared the community structure of benthic algae inside and outside pomacentrid damselfish (S... more We compared the community structure of benthic algae inside and outside pomacentrid damselfish (Stegastes nigricans) territories in a moat at Sesoko Island, Okinawa, Japan. S. nigricans maintained ''algae farms'' that were dominated by the filamentous rhodophyte, Womersleyella setacea. Species richness and biomass were higher inside damselfish territories than outside, while species diversity and evenness were higher outside. Detrended correspondence analysis (DCA) based on species composition showed that the dominance of W. setacea was maintained throughout the year in all samples collected from inside damselfish territories. The observed strong dominance of filamentous rhodophytes was consistent with the findings of most studies on damselfish territories worldwide. However, the dominance of a single species of alga and low species diversity inside the territories was in contrast to the findings of previous studies, in which the reduction of grazing pressure caused intermediate disturbance and enhanced algal species diversity. This discrepancy in algal species diversity inside the damselfish territories seems to have been caused by unique characteristics of the alga and the fish. W. setacea traps sediment, which reduces the availability of firm substrata for attachment and inhibits the recruitment of some algae. Moreover, S. nigricans ''weeds'' indigestible calcareous and thicker algae. The algal assemblage outside damselfish territories varied among samples, and included mat-forming cyanophytes (Calothrix aeruginosa and Calothrix codicola), a prostrate laminar phaeophyte (Padina sp.), thin and small-scaled algae (Cladophora sp. and Feldmannia indica), finely branched filamentous rhodophytes (Taenioma perpusillum and Herposiphonia obscura), and a coarsely branched rhodophyte (Gelidiopsis variabilis).

BMC biology, Jan 29, 2014

BackgroundLake Tanganyika, an ancient lake in the Great Rift Valley, is famous for the adaptive r... more BackgroundLake 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.ResultsBased 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 composi...

Species-diverse coral communities on an artificial substrate at a tuna farm in Amami, Japan

Marine Environmental Research, 2013

Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the ... more Tuna-farming is expanding worldwide, necessitating the monitoring/managing of its effects on the natural environment. In Japan, tuna-farming is conducted on coral reefs that have been damaged by mass-bleaching events and crown-of-thorns starfish (COTS) outbreaks. This study focused on the coral community on an artificial substrate of tuna-farm to reveal the possible effects of tuna-farming on the natural environment. Corals flourished on ropes suspended in the farm in the Amami Islands, southern Japan. These were moored 3 m below the sea-surface in 50-m-deep water. The coral community on the rope was analyzed and compared with those on natural substrata on two adjacent COTS-damaged reefs and with that in a protected reef. Corals were monitored throughout a year. Sixty coral species grew on the ropes, that corresponds to 27.3% of the 220 species known from Amami. The coral community was unique, dominated by massive faviid corals. On the ropes, the water temperature rarely exceeded 30.0 °C and no corals on the rope were severely bleached or covered by sedimentation during the observations. The tuna-farm infrastructure provided corals with a suitable habitat, and species-rich coral communities were established. These coral communities are an important node connecting tuna-farms and the natural environment.

Advantage of harmlessness in gaining preferential access to a heterospecific territory

Journal of Fish Biology, 2007

ABSTRACT Underwater observations conducted in the shallow waters of the southern part of Lake Tan... more ABSTRACT Underwater observations conducted in the shallow waters of the southern part of Lake Tanganyika showed that a zoobenthos-eating cichlid Neolamprologus mustax preferentially foraged in the permanent territory of an algivorous cichlid Neolamprologus moorii, even though other zoobenthos-eaters were chased out. Benthic invertebrates were much richer within the territory of N. moorii than outside, suggesting that the territory was an attractive feeding ground for zoobenthos-eaters. Stomach contents analysis showed that N. mustax rarely ate fish broods, although other zoobenthos-eaters often did so. It is concluded that the differential tolerance of N. moorii towards zoobenthos-eaters based on their harmfulness to broods benefits harmless N. mustax by allowing its use of the prey-rich territory.

Journal of Experimental Marine Biology and Ecology, 2002

We compared the community structure of benthic algae inside and outside pomacentrid damselfish (S... more We compared the community structure of benthic algae inside and outside pomacentrid damselfish (Stegastes nigricans) territories in a moat at Sesoko Island, Okinawa, Japan. S. nigricans maintained ''algae farms'' that were dominated by the filamentous rhodophyte, Womersleyella setacea. Species richness and biomass were higher inside damselfish territories than outside, while species diversity and evenness were higher outside. Detrended correspondence analysis (DCA) based on species composition showed that the dominance of W. setacea was maintained throughout the year in all samples collected from inside damselfish territories. The observed strong dominance of filamentous rhodophytes was consistent with the findings of most studies on damselfish territories worldwide. However, the dominance of a single species of alga and low species diversity inside the territories was in contrast to the findings of previous studies, in which the reduction of grazing pressure caused intermediate disturbance and enhanced algal species diversity. This discrepancy in algal species diversity inside the damselfish territories seems to have been caused by unique characteristics of the alga and the fish. W. setacea traps sediment, which reduces the availability of firm substrata for attachment and inhibits the recruitment of some algae. Moreover, S. nigricans ''weeds'' indigestible calcareous and thicker algae. The algal assemblage outside damselfish territories varied among samples, and included mat-forming cyanophytes (Calothrix aeruginosa and Calothrix codicola), a prostrate laminar phaeophyte (Padina sp.), thin and small-scaled algae (Cladophora sp. and Feldmannia indica), finely branched filamentous rhodophytes (Taenioma perpusillum and Herposiphonia obscura), and a coarsely branched rhodophyte (Gelidiopsis variabilis).

Ecological Research, 2011

The territorial damselfish, Stegastes nigricans, maintains algal farms by excluding invading herb... more The territorial damselfish, Stegastes nigricans, maintains algal farms by excluding invading herbivores and weeding unpalatable algae from its territories. In Okinawa, Japan, S. nigricans farms are exclusively dominated by Polysiphonia sp., a highly digestible filamentous rhodophyte. This study was aimed at determining the diet of S. nigricans in Okinawa and its dependency on these almost-monoculture algal farms based on stomach contents and chemical analyses. Stomach content analyses revealed that all available food items in the algal farms (i.e., algae, benthic animal inhabitants, trapped detritus) were contained in fish stomachs, but amorphous organic matter accounted for 68% of the contents. Therefore, carbon and nitrogen stable isotope ratios and fatty acid (FA) compositions were analyzed to trace items actually assimilated in their bodies. Stable isotope analyses showed that benthic animals were an important food source even for this farmer fish. Two essential FAs (EFA), 20:4n6 and 20:5n3, which are produced only by rhodophytes among available food items, were rich in the muscle tissue of S. nigricans as well as in algal mats and detritus, suggesting that algal mats contribute EFAs to S. nigricans directly and indirectly through the food web. In conclusion, S. nigricans ingested algal mats, detritus and benthic animals maintained within its farm. Algae and detritus were original sources of EFAs, and benthic animals, which were much more abundant in the farms than in outside territories, provided a nitrogen-rich dietary source for the fish.

Biology Letters, 2006

In cultivation mutualisms, farming animals prepare fields for cultivars, enhance their growth and... more In cultivation mutualisms, farming animals prepare fields for cultivars, enhance their growth and harvest them. For example, in terrestrial ecosystems, plant–herbivore cultivation mutualisms arose between humans and their crops only relatively recently. We discovered an obligate cultivation mutualism between a damselfish and an alga in a coral reef ecosystem. The damselfish, Stegastes nigricans , manages algal farms through territorial defence against the invading grazers and through weeding of unpalatable algae. As a result, the algal farms of S. nigricans are dominated by one species, Polysiphonia sp. We performed an exhaustive survey of algal assemblages inside and outside the territories of five damselfish species around the Ryukyu Islands, Japan, using molecular and morphological characteristics. Polysiphonia sp. 1 grew exclusively inside the farms of S. nigricans , and never elsewhere. Since only Polysiphonia sp. 1 is harvested and consumed by the damselfish as a staple food, ...

by Ian Donohue, Franziska Schädelin, Kevin Schneider, Jacco van Rijssel, Romulus Abila, Diogo Antunes, Taylor Banda, Auguste Chocha Manda, Peter Akoll, Karoline Fritzsche, Hugo F. Gante, M Genner, Hiroki Hata, Joachim Frommen, Arne Jungwirth, Luc Janssens de Bisthoven, Prince Kaleme, Stephan Koblmüller, Anton Lamboj, Pascal Masilya, Loïc Kéver, Ad Konings, Gaspard Ntakimazi, W. Okello, Lobomir Pialek, Pierre Denis Plisnier, Jelena Rajkov, Joost A M Raeymaekers, Isa Schoen, Pooja Singh, George Turner, Alexandra Tyers, Alexandra A - T Weber, Holger Zimmermann, Ola Svensson, and Maarten Vanhove

Inheritance patterns of morphological laterality in mouth opening of zebrafish, Danio rerio

Laterality, 2012

Inheritance Patterns of Lateral Dimorphism Examined through Breeding Experiments in Tanganyikan Cichlid (Julidochromis transcriptus) and Japanese Medaka ( …

Zoological science, 2012

Demise of monocultural algal farms by exclusion of territorial damselfish

Marine Ecology-progress Series, 2003

BMC Evolutionary Biology, 2010

Background: On coral reefs, damselfish defend their territories from invading herbivores and main... more Background: On coral reefs, damselfish defend their territories from invading herbivores and maintain algal turfs, from which they harvest filamentous algae. In southern Japan, intensive weeding of indigestible algae by Stegastes nigricans results in overgrowth by one filamentous alga, Polysiphonia sp. 1. Because this alga is highly susceptible to grazing and is competitively inferior to other algae, it survives only within the protective territories of this fish species, suggesting an obligate mutualism between damselfish and their cultivated alga. The wide distribution of damselfish species through the Indo-Central Pacific raises the question of whether this species-specific mutualism is maintained throughout the geographic range of the fish. To address this question, from all 18 damselfish species we conducted comprehensive surveys of algal flora within their territories throughout the Indo-West Pacific, and identified species of Polysiphonia using morphological examination and gene sequencing data.

Monoculture and mixed-species algal farms on a coral reef are maintained through intensive and extensive management by damselfishes

Journal of experimental marine biology and ecology, 2004

Marine Ecology-progress Series, 2002

Resident herbivorous damselfishes (Pisces: Pomacentridae) exclude other herbivores from their ter... more Resident herbivorous damselfishes (Pisces: Pomacentridae) exclude other herbivores from their territories and reduce the grazing pressure within these territories. Among the damselfish, Stegastes nigricans is unique in that it manages a virtual monoculture dominated by the erect filamentous rhodophyte Womersleyella setacea, whereas many other herbivorous damselfishes maintain species-rich farms. We observed the behavior of S. nigricans in a lagoon in Okinawa, Japan, and discovered that this species intensively weeded out specific algae. To analyze weeding selectivity, we compared the algae picked up and discarded by S. nigricans to the algal assemblage found inside the territory. To examine the digestibility of each algal species, 10 damselfish were collected, and algae removed from their stomachs were compared with those found in the intestine and faeces. Inside their territories, S. nigricans selectively weeded out indigestible algae. These algae were latecolonizing species, and the intensive weeding suppressed algal growth beyond early successional stages. Consequently, selective weeding enabled the fish to maintain virtual monocultural farms of a digestible early colonizer, W. setacea, inside their territories.