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1.
Effects of anemonefish on giant sea anemones: expansion behavior,growth, and survival 总被引:6,自引:0,他引:6
The symbiosis between giant sea anemones and anemonefish on coral reefs is well known, but little information exists on impacts
of this interaction on the sea anemone host. On a coral reef at Eilat, northern Red Sea, individuals of the sea anemone Entacmaea quadricolor that possessed endemic anemonefish Amphiprion bicinctus expanded their tentacles significantly more frequently than did those lacking anemonefish. When anemonefish were experimentally
removed, sea anemone hosts contracted partially. Within 1–4 h in most cases, individuals of the butterflyfish Chaetodon fasciatus arrived and attacked the sea anemones, causing them to contract completely into reef holes. Upon the experimental return
of anemonefish, the anemone hosts re-expanded. The long-term growth rate and survival of the sea anemones depended on the
size and number of their anemonefish. Over several years, sea anemones possessing small or no fish exhibited negative growth
(shrinkage) and eventually disappeared, while those with at least one large fish survived and grew. We conclude that host
sea anemones sense the presence of symbiotic anemonefish via chemical and/or mechanical cues, and react by altering their
expansion behavior. Host sea anemones that lack anemonefish large enough to defend them against predation may remain contracted
in reef holes, unable to feed or expose their tentacles for photosynthesis, resulting in their shrinkage and eventual death. 相似文献
2.
The ecological performance of the sea anemone Heteractis magnifica was examined during a 36-month experiment with respect to season and the presence and numbers of a mutualist (orange-fin anemonefish Amphiprion chrysopterus). Anemones primarily grew during the autumn, with most asexual reproduction occurring in winter; mortality was not strongly seasonal. Individual growth rates did not differ between anemones harboring one or two anemonefish, but these rates were three times faster than for anemones lacking Amphiprion. Anemones with two anemonefish had the highest fission rate, whereas those without anemonefish had the lowest. By contrast, anemones that were not defended by anemonefish suffered higher-than-expected mortality. As a consequence, anemones with two Amphiprion had the greatest net increase in surface area, and those lacking anemonefish had a negligible gain that was statistically indistinguishable from zero after three years. Anemonefish not only enhanced anemone survivorship as previously believed, they also fostered faster growth and more frequent asexual reproduction. 相似文献
3.
Coral bleaching and related reef degradation have caused significant declines in the abundance of reef-associated fishes.
Most attention on the effects of bleaching has focused on corals, but bleaching is also prevalent in other cnidarians, including
sea anemones. The consequences of anemone bleaching are unknown, and the demographic effects of bleaching on associated fish
recruitment, survival, and reproduction are poorly understood. We examined the effect of habitat degradation including host
anemone bleaching on fish abundance, egg production, and recruitment of the panda anemonefish (Amphiprion polymnus) near Port Moresby, Papua New Guinea. Following a high-temperature anomaly in shallow waters of the region, most shallow
anemones to a depth of 6 m (approximately 35% of all the anemones in this area) were severely bleached. Anemone mortality
was low but bleached anemones underwent a ~34% reduction in body size. Total numbers of A. polymnus were not affected by bleaching and reduction in shelter area. While egg production of females living in bleached anemones
was reduced by ~38% in 2009 compared to 2008, egg production of females on unbleached anemones did not differ significantly
between years. Total recruitment in 2009 was much lower than in 2008. However, we found no evidence of recruiting larvae avoiding
bleached anemones at settlement suggesting that other factors or different chemical cues were more important in determining
recruitment than habitat quality. These results provide the first field evidence of detrimental effects of climate-induced
bleaching and habitat degradation on reproduction and recruitment of anemonefish. 相似文献
4.
Jeremy S. Mitchell 《Environmental Biology of Fishes》2003,66(1):85-90
For reef fishes that do not move between habitat patches following settlement, habitat selection is expected during settlement. Although false clown anemonefish, Amphiprion ocellaris, are sedentary following settlement, they are not especially discriminating during settlement, and are commonly found occupying anemones at which no apparent nest site exists. In this study I report on mobility of Stichodactyla gigantea sea anemones, including anemones with resident false clowns. I argue that anemone mobility can help explain why settling false clowns are not more discriminating: although the per annum probability of an anemone moving is low, the probability of that anemone moving over the course of a resident's life is considerably higher. Therefore, an anemone's current microhabitat may not be a good predictor of its microhabitat and suitability as a host in the future. 相似文献
5.
Modi Roopin Daniel J. Thornhill Scott R. Santos Nanette E. Chadwick 《Symbiosis (Philadelphia, Pa.)》2011,53(2):63-74
Despite the ecological importance of anemonefish symbioses, little is known about how nutritional contributions from anemonefish
interact with sea anemone physiology and Symbiodinium (endosymbiotic dinoflagellate) genetic identity under field conditions. On Red Sea coral reefs, we measured variation in
ammonia concentrations near anemones, excretion rates of anemonefish, physiological parameters of anemones and Symbiodinium, and genetic identity of Symbiodinium within anemones. Ammonia concentrations among anemone tentacles were up to 49% above background levels, and anemonefish excreted
ammonia significantly more rapidly after diurnal feeding than they did after nocturnal rest, similar to their excretion patterns
under laboratory conditions. Levels of 4 physiological parameters (anemone protein content, and Symbiodinium abundance, chlorophyll a concentration, and division rate) were similar to those known for laboratory-cultured anemones, and in the field did not
depend on the number of anemonefish per anemone or depth below sea surface. Symbiodinium abundance varied significantly with irradiance in the shaded reef microhabitats occupied by anemones. Most anemones at all
depths harbored a novel Symbiodinium 18S rDNA variant within internal transcribed spacer region 2 (ITS2) type C1, while the rest hosted known ITS2 type C1. Association
with Symbiodinium Clade C is consistent with the symbiotic pattern of these anemones on other Indo-Pacific reefs, but the C1 variant of Symbiodinium identified here has not been described previously. We conclude that in the field, anemonefish excrete ammonia at rapid rates
that correlate with elevated concentrations among host anemone tentacles. Limited natural variation in anemonefish abundance
may contribute to consistently high levels of physiological parameters in both anemones and Symbiodinium, in contrast to laboratory manipulations where removal of fish causes anemones to shrink and Symbiodinium to become less abundant. 相似文献
6.
Configuration of small patch reefs and population abundance of a resident reef fish in a complex coral reef landscape 总被引:1,自引:0,他引:1
Habitat use by the resident coral reef anemonefish, Amphiprion frenatus, was examined in the complex coral reef landscape of Shiraho Reef, Ishigaki Island, Okinawa, Japan, using an enlarged color
aerial photograph processed using image analysis software as an accurate field map. The anemonefish inhabit assemblages of
the host sea anemone, Entacmaea quadricolor (clonal type), which inhabit various patch reefs in the back reef moat. We located all patch reefs inhabited by the host
in the map based on snorkel observations: 297 anemonefish were found in 93 host assemblages in the study site of 2.9 ha. These
patch reefs could be recognized by the reef colors, including the shadows (blackish color) in the photograph. Using image
analysis software, the colors of the patch reefs were chosen and pixels with the same color values were regarded as potential
habitat patches for the fish (PHPs). PHPs were 3D patch reefs (>0.5 m in height). Total areas (TA) and total perimeters (TP)
of PHPs were measured in nine quadrats in the digitized aerial photograph. Host abundance and anemonefish abundance in a quadrat
showed stronger correlations with the product of TA and TP of PHPs than TA alone. A site with numerous large 3D patch reefs
(≥0.75 m2 in situ) can be a better habitat for the fish than other sites consisting of several huge 3D patch reefs of the same total
area. The methodology applied here may be useful for assessing the quality of habitats for small resident animals in shallow
subtidal reefs. 相似文献
7.
Modi Roopin Nanette E. Chadwick 《Journal of experimental marine biology and ecology》2009,370(1-2):27-34
Large ectosymbionts (especially fishes and crustaceans) may have major impacts on the physiology of host cnidarians (sea anemones and corals), but these effects have not been well quantified. Here we describe impacts on giant sea anemone hosts (Entacmaea quadricolor) and their endosymbiotic zooxanthellae (Symbiodinium spp.) from the excretion products of anemonefish guests (Amphiprion bicinctus) under laboratory conditions. Starved host anemones were maintained with anemonefish, ammonia supplements (= NH3 gas and NH4+ ion), or neither for 2 mo. In the presence of external ammonia supplements or resident anemonefish, the zooxanthellae within host anemones increased in abundance (173% and 139% respectively), and provided the hosts with energy that minimized host body size loss. In contrast, anemones cultured with neither ammonia nor anemonefish harbored significantly lower abundances of zooxanthellae (84% of initial abundance) and decreased > 60% in body size. Although they maintained higher zooxanthella abundances, anemones cultured with either ammonia supplements or resident anemonefish exhibited significantly lower ammonia uptake rates (0.065 ± 0.005 µmol g- 1 h- 1, and 0.052 ± 0.018 µmol g- 1 h- 1 respectively) than did control anemones (0.119 ± 0.009 µmol g- 1 h- 1), indicating that their zooxanthellae were more nitrogen sufficient. We conclude that, in this multi-level mutualism, ammonia supplements provide essentially the same level of physiological contribution to host anemones and zooxanthellae as do live resident fish. This nutrient supplement reduces the dependence of the zooxanthellae on host feeding, and allows them to provide abundant photosynthetically-produced energy to the host. 相似文献
8.
The protandrous anemonefish Amphiprion frenatus often forms a group consisting of a large female, a small male, and a smaller nonbreeder at an isolated single host anemone,
where home ranges of subordinates were covered with the female's home range. Within the group, the dominant individuals suppress
the growth of subordinates, resulting in large size differences. The spacing pattern and body size composition of A. frenatus on colonial hosts were investigated in Ishigaki Island, Okinawa, Japan. Six breeding pairs and 14 nonbreeders inhabited a
colony of 157 anemones. Each pair maintained a territory in which pair members used different hosts. Nonbreeders had unstable
home ranges on the outskirts of or in the pairs' territories. Body size differences between males and females in pairs and
between males and nonbreeders were small. The small size differences in the colony of hosts are caused by reduced suppression
of growth of subordinates by the dominant individuals. The total area of host anemones largely affects spacing pattern and
social suppression of the anemonefish. 相似文献
9.
Habitat loss due to land reclamation often occurs in sandy coral reef shore zones. The giant sea anemone Stichodactyla gigantea, which harbors the false clown anemonefish Amphiprion ocellaris, both of which are potentially flagship species, inhabit these places. To assess habitat quality for S. gigantea, we examined correlative associations between the number and the body size of S. gigantea and the amount of habitat types in fine-scale seascape composition quantified from an enlarged section of a high-resolution
(1/2,500) color aerial photograph of the shallow shore zone of Shiraho Reef, Ishigaki Island, Japan. This study confirmed
that anemones were most abundant at the edges of dense seagrass beds characterized by shallow sandy bottoms, rock beds, and
sparse seagrass beds, while they were less abundant in coral patch reefs. However, anemones inhabiting coral patch reefs were
significantly larger and their rate of disappearance over 3 years was lower than those inhabiting other habitats. This suggests
that coral patch reefs may be more suitable habitats supporting larger animals and greater persistence of S. gigantea. The visual census techniques applied here, combined with aerial photography and image-analysis software, may be useful as
a simple analytical tool for local assessment of suitable habitats for relatively small-bodied marine fauna in shallow-water
seascapes. 相似文献
10.
Robert M. Ross 《Ethology : formerly Zeitschrift fur Tierpsychologie》1978,46(1):71-83
Field observations and experiments on the Indo-Pacific anemonefish Amphiprion melanopus at Guam show that it colonizes the aggregating sea anemone Physobrachia douglasi extensively and nearly exclusively. There are an average of four fish per colony. The total standard length of anemonefish at each aggregation is highly correlated with the total area covered by resident anemones, suggesting both a carrying capacity and some form of social control of growth of anemonefish2). Inter-colony migration of juveniles, as well as larval recruitment, may contribute to maintenance of the optimum colony size. Adults do not migrate. Both juveniles and adults defend territory. Juvenile territories are mutually exclusive areas within the confines of the anemone aggregation, while adult territories are considerably larger than the area covered by the anemone aggregation. Though territories of mated ♀♀ and ♂♂ overlap completely, female emphasis is peripheral relative to the ♂. Adult conspecific intruders are attacked more heavily and at greater distances than are juveniles. Intraspecific territoriality in juveniles probably reflects the limited availability of critical habitat. In adults it may function to protect the pair bond. Interspecific aggression is less intense and appears to protect both the spawn and host anemones from various predators. 相似文献
11.
Ashley J. Frisch Justin R. Rizzari Katherine P. Munkres Jean-Paul A. Hobbs 《Coral reefs (Online)》2016,35(2):375-386
Intimate knowledge of both partners in a mutualism is necessary to understand the ecology and evolution of each partner, and to manage human impacts that asymmetrically affect one of the partners. Although anemonefishes and their host anemones are iconic mutualists and widely sought by ornamental fisheries, the degree to which anemones depend on anemonefishes, and thus the colony-level effects of collecting anemonefishes, is not well understood. We tracked the size and abundance of anemone Entacmaea quadricolor and anemonefish Amphiprion melanopus colonies for 3 yr after none, some, or all of the resident anemonefish were experimentally removed. Total and partial removal of anemonefish had rapid and sustained negative effects on growth, reproduction and survival of anemones, as well as cascading effects on recruitment and productivity of anemonefish in the remaining colony. As predicted, total removal of anemonefish caused acute declines in size and abundance of anemones, although most anemone colonies (76 %) slowly resumed growth and reproduction after the arrival of anemonefish recruits, which subsequently grew and defended the hosts. Partial removal of anemonefish had similar but typically less severe effects on anemones. Remarkably, the colony-level effects on anemones and anemonefish were proportional to the size and number of anemonefish that were experimentally removed. In particular, anemone survival and anemonefish productivity were highest when one or more adult anemonefish remained in the colony, suggesting that adult fish not only enhanced the protection of anemones, but also increased the recruitment and/or survival of conspecifics. We conclude that the relationship between E. quadricolor and A. melanopus is not only obligate, but also demographically rigid and easily perturbed by anemonefish fisheries. Clearly, these two species must be managed together as a unit and with utmost precaution. To this end, we propose several tangible management actions that will help to minimize fishing effects. 相似文献
12.
D. L. Dixson 《Coral reefs (Online)》2012,31(1):255-261
Predation rates of marine species are often highest during the transition from the pelagic to the benthic life stage. Consequently,
the ability to assess predation risk when selecting a settlement site can be critical to survival. In this study, pairwise
choice trials were used to determine whether larvae of three species of anemonefish (Amphiprion melanopus, A. percula and Premnas biaculeatus) are able to (1) assess the predation risk of potential anemone settlement sites through olfactory cues alone and (2) alter
their settlement choices depending on the options available (host or non-host anemone). When predation risk was assessed with
host and non-host anemone species independently, all species of anemonefish significantly chose the odor associated with the
low-risk settlement option over the high-risk site. Most importantly, all species of anemonefish selected water with olfactory
cues from their host anemone regardless of predation risk when paired against non-host anemone odor. These results demonstrate
that larval reef fishes can use olfactory cues for complex risk assessment during settlement-site selection; however, locating
the correct habitat is the most important factor when selecting a settlement site. 相似文献
13.
Masaaki Sato Kentaro Honda Klenthon O. Bolisay Yohei Nakamura Miguel D. Fortes Masahiro Nakaoka 《Hydrobiologia》2014,733(1):63-69
Many marine organisms disperse or migrate among habitats, which affects their abundance patterns at individual local habitats. To clarify the factors affecting the distribution patterns of two anemonefishes (Amphiprion frenatus and A. perideraion), we measured the habitat patch size (anemone size), patch isolation (mean distance from other anemones), presence/absence of other anemonefish species, depth, and abundance of the two anemonefishes at each anemone around a semi-closed bay (up to 3.7 km) in Puerto Galera, the Philippines. We assumed that local abundance increases with habitat size and decreases with patch isolation because of greater resource availability and reduced rates of recruitment from other patches. Local abundance of A. frenatus was related to habitat size and the presence of other anemonefish species, whereas that of A. perideraion was affected by the presence of other anemonefish species and water depth. Interspecific competition and/or niche differentiation of habitat can explain the negative relationship between the local abundance of the target species and other anemonefish. Patch isolation was not significant for both species probably because the dispersal rate was not directly proportional to the geographic distance between patches at our study site. 相似文献
14.
Behaviours of Clark's anemonefish Amphiprion clarkii and the dusky anemonefish Amphiprion melanopus were studied in Vanuatu. Six anemones and their resident fish were observed for typical behaviours (hiding, watching, roaming, inter-, and intraspecific behaviour) with and without the presence of a snorkelling observer. Observer presence had significant but contrasting effects on hiding behaviour in A. clarkii and A. melanopus. Bolder anemonefish species may be able to outcompete other species in areas with high human presence. 相似文献
15.
Akihisa Hattori 《Austral ecology》2000,25(2):187-192
The effect of a larger anemonefish Amphiprion clarkii (Bennett) on the social and mating system of a smaller congener Amphiprion perideraion (Bleeker) was investigated on a coral reef at Okinawa, Japan, where both species use the same host sea anemone Heteractis crispa (Ehrenberg). The population of A. perideraion consisted of adult, subadult and juvenile groups. Adult groups, which consisted of one or two adults and a varying number of subadults and juveniles, usually did not share the host with A. clarkii. In contrast, subadult and juvenile groups, which included no adults, always cohabited with A. clarkii. In the heterospecific groups, subadult A. perideraion were able to mature histologically, and changed to female when they were the largest among conspecific members, although their reproduction was suppressed by A. clarkii. After all members of A. clarkii emigrated or disappeared from a heterospecific group, adult A. perideraion could begin breeding. I suggest that A. perideraion in both heterospecific and conspecific groups adopt a mating strategy that involves waiting for vacated breeding posts because of their low mobility and a low host density. 相似文献
16.
Daphne Gail Fautin 《Environmental Biology of Fishes》1986,15(3):171-180
Synopsis The 25 species ofAmphiprion and one ofPremnas (family Pomacentridae) are obligate symbionts of 10 species of facultatively symbiotic sea anemones. Throughout the tropical
Indo-West Pacific range of the relationship, a fish species inhabits only certain of the hosts potentially available to it.
This specificity is due to the fishes. Five fishes occupy six sea anemone species at Lizard Island, Great Barrier Reef, Australia.Entacmaea quadricolor harborsP. biaculeatus, A. melanopus andA. akindynos. Adults ofPremnas occur deeper than about 3 m in large, primarily solitary actinians; juveniles may occupy peripheral members ofEntacmaea clones in shallow water. Specimens ofA. melanopus live exclusively in clonal anemones, which are found no deeper than 3 m. Most individuals ofA. akindynos inEntacmaea are juveniles, occurring shallow and deep, in solitary anemones or at the margins of clones. Interspecific as well as intraspecific
social control of growth may be responsible for keeping fish small at clone fringes. Conspicuous specimens ofE. quadricolor depend upon their anemonefish to survive. Actinians cleared of symbionts disappeared within 24 h, probably having been eaten
by reef fishes.Entacmaea, the most abundant and widespread host actinian at Lizard Island and throughout the range of the association, is also arguably
the most attractive to anemonefishes. I believe its vulnerability to predation was a factor in its evolving whatever makes
it desirable to fishes. Experimental transfers pitted fish of one species against those of another, controlling for ecophenotype
of host, and sex, size and number of fish. Competitive superiority was in the same order as abundance and over-all host specificity:P. biaculeatus, A. melanopus, A. akindynos. At least three factors are necessary to explain patterns of species specificity - innate or learned host preference, competition,
and stochastic processes. 相似文献
17.
Twenty-six species of anemonefish of the genera Amphiprion and monospecific Premnas, use only 10 species of anemones as hosts in the wild (Families: Actiniidae, Stichodactylidae and Thalassianthidae). Of these 10 anemone species some are used by multiple species of anemonefish while others have only a single anemonefish symbiont. Past studies have explored the different patterns of usage between anemonefish species and anemone species; however the evolution of this relationship remains unknown and has been little studied over the past decade. Here we reopen the case, comparing the toxicity of crude venoms obtained from anemones that host anemonefish as a way to investigate why some anemone species are used as a host more than others. Specifically, for each anemone species we investigated acute toxicity using Artemia francisca (LC50), haemolytic toxicity using ovine erythrocytes (EC50) and neurotoxicity using shore crabs (Ozius truncatus). We found that haemolytic and neurotoxic activity varied among host anemone species. Generally anemone species that displayed greater haemolytic activity also displayed high neurotoxic activity and tend to be more toxic on average as indicated by acute lethality analysis. An overall venom toxicity ranking for each anemone species was compared with the number of anemonefish species that are known to associate with each anemone species in the wild. Interestingly, anemones with intermediate toxicity had the highest number of anemonefish associates, whereas anemones with either very low or very high toxicity had the fewest anemonefish associates. These data demonstrate that variation in toxicity among host anemone species may be important in the establishment and maintenance of anemonefish anemone symbiosis. 相似文献
18.
Akihisa Hattori 《Environmental Biology of Fishes》1995,42(4):345-353
Synopsis Social structure and interactions between the anemonefishes, Amphiprion clarkii and A. perideraion, which utilize the same host sea anemone Radianthus kuekenthali, were investigated on a coral reef of Okinawa Islands, Japan. In an 87 × 373 m2 study area, 98 sea anemones were inhabited by both species (32.5%), by only A. clarkii (48.9%), or by only A. perideraion (18.6%). A group of A. clarkii often occupied two or more individual hosts, and group members often interchanged. However, a group of A. perideraion usually used only one host and migration between groups was rare. The larger A. clarkii suppressed reproduction of A. perideraion in cohabiting groups, while A. perideraion suppressed settlement of Juvenile A. clarkii to its own hosts. Juvenile A. clarkii settled on small hosts as well as on large hosts, whereas juvenile A. perideraion settled only on large hosts. Coexistence appears to be possible in part by differences in settlement patterns between juveniles of the two anemonefishes. 相似文献
19.
Eric K. Bollinger Paul V. Switzer Jesse Pfammatter Jason Allen 《Ichthyological Research》2008,55(4):394-398
We studied group formation and anemone use in captively reared anemonefish Amphiprion frenatus. Four small fish (23–32 mm total length) were simultaneously released into a central area of the aquaria (ca. 160 l) that
was divided in half with an anemone placed on each half, with the opportunity to settle on either side. Four-day trials were
conducted for analyzing settlement patterns. Because of the monogamous mating system, we predicted that small fish should
settle in pairs. However, all four small fish settled on the same side in 7 of 14 replicates, which was a higher than expected
value under random settlement. 相似文献
20.
Akihisa Hattori 《Ichthyological Research》2005,52(1):57-63
Protandry in anemonefishes has been attributed to random pair formation, which results from their limited mobility after random recruitment to isolated host anemones. The recruitment and movement of the anemonefish Amphiprion frenatus were investigated in relation to its group structure and the spatial distribution of its host anemone on a coral reef, where it inhabits isolated single hosts and interhost movement is rare. A juvenile tended to be recruited to a host from which a former resident(s) had disappeared, indicating that larval recruitment is not random. After mass bleaching of corals during which many hosts died, a quarter of adults moved between hosts on average 42m in 3 weeks, indicating that their mobility is potentially high. The few migrations under normal conditions were probably due to the low benefit of movements. Even after the movements, a female was much larger than her mate in a host, and a large female tended to pair with a large male. Although body size of females was positively correlated with their host size, that of males was not. It is suggested that the size of a single host does not allow the coexistence of two or more large fish, and the size composition of each pair is affected by the host size. Protandry in the monogamous fish may be attributed to the nonrandom pair formation in the limited space of a host. 相似文献