Intraspecific interactions in a scleractinian coral, Galaxea fascicularis: Induced formation of sweeper tentacles

Hidaka, Michio; Yamazato, K.

doi:10.1007/bf00263757

Cited by 50 publications

(54 citation statements)

References 18 publications

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“…Similar descriptions were published by Richardson et al (1979), Chornesky (1983) and Hidaka & Yamazato (1984) for various coral species. In addition to their unique shape, sweeper tentacles differ from feeding tentacles in the composition of their nematocysts and in their nematocyst-to-spirocyst ratio.…”

Section: Introductionsupporting

confidence: 68%

“…The total number of sweeper tentacles observed on each colony was also recorded. Sweeper tentacles were defined as long tentacles possessing an enlarged tip relative to the stalk (den Hartog 1977, Hidaka & Yamazato 1984, in contrast to feeding tentacles, which were defined as short, tapered tentacles. Another feature of feeding tentacles is the batteries of nematocysts along the stalk, whereas the stalk of sweeper tentacles appears smooth (Fig.…”

Section: Methodsmentioning

confidence: 99%

“…Corals compete with each other indirectly via overtopping, whereby one colony overshadows another and thus presents sufficient light or water flow from reaching its opponent, or directly, whereby corals contact and damage the soft tissues of opponents (Connell 1973, Purkis & Riegel 2004. Stony corals have developed an array of mechanisms to injure their neighbors and clear space for further colony growth, including (1) extracoelenteric digestion, whereby the mesenterial filaments normally used for feeding serve as aggressive organs and digest the tissues of adjacent corals (Lang 1973), (2) unusually elongated polyps termed 'sweeper polyps', which are used by only a few genera of corals to damage their neighbors (Peach & Guldberg 1999), (3) secretion of a thick layer of mucus containing numerous nematocysts that cause necrosis and sloughing in neighboring corals, used mainly by fungiid corals (Chadwick 1988), and (4) sweeper tentacles, which are elongate tentacles that develop from normal feeding tentacles (Hidaka & Yamazato 1984).…”

Section: Introductionmentioning

confidence: 99%

“…Intermediate forms, in terms of tentacle shape and nematocyst composition, are recognized between feeding tentacles and sweeper tentacles. Sweeper tentacles are not invariant structures, but have the ability to revert back to feeding tentacles over several weeks if contact between opponent corals ceases (den Hartog 1977, Wellington 1980, Hidaka & Yamazato 1984.…”

Section: Introductionmentioning

confidence: 99%

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Sweeper tentacles of the brain coral Platygyra daedalea: induced development and effects on competitors

Lapid¹,

Wielgus²,

Chadwick-Furman³

2004

Mar. Ecol. Prog. Ser.

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Benthic marine organisms utilize an array of defensive and aggressive mechanisms that affect competition for space on hard marine substrata. The sweeper tentacles of stony corals are inducible aggressive organs used during competition, but they also may serve a pre-emptive defensive function. About half of the colonies of the brain coral Platygyra daedalea at Eilat, northern Red Sea, possess sweeper tentacles, many of which are not directed toward neighboring corals. These randomly oriented sweeper tentacles may be produced in order to detect the settlement or advance of corals occurring at > 5 cm distance from the colony. Of coral colonies < 5 cm distant from P. daedalea, about 43% exhibit tissue damage facing the interaction area. Adjacent corals with the most damage belong to the genera Favites and Leptastrea, while colonies of Millepora and congeneric Platygyra exhibit significantly less damage. Tissue damage of neighboring coral colonies decreases significantly with increasing distance from P. daedalea. The presence of sweeper tentacles on brain corals correlates significantly with colony diameter, but not with the number of neighboring colonies. The aggressive reach of P. daedalea in Eilat is 5.3 ± 3.0 cm, longer than previously reported for members of this genus. Under laboratory conditions, sweeper tentacles develop on P. daedalea colonies about 30 d following initial contact with colonies of the common massive coral F. complanata, and at approximately 50 d they reach a maximum length of about 6.5 cm, 10 × longer than feeding tentacles. Sweeper tentacles cause increasing tissue damage to F. complanata colonies over 2 mo. During morphogenesis, their tip-to-stalk ratio and ectoderm thickness doubles, indicating acrosphere development, but maximal width of the tentacle stalk does not change. Sweeper tentacles appear to be a common agonistic mechanism among stony corals, and may serve also as a defensive mechanism that allows the persistence of some species in crowded reef habitats.

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Section: Introductionsupporting

confidence: 68%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Sweeper tentacles of the brain coral Platygyra daedalea: induced development and effects on competitors

Lapid¹,

Wielgus²,

Chadwick-Furman³

2004

Mar. Ecol. Prog. Ser.

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“…There are indications that this may also be the case for Favia speciosa and Diploastrea heliopora. The observed changes in pigmentation are typical of those known to be related to light (Kawaguti 1944, Brown et al 1999, Dove et al 2001, and budding (associated with high light conditions) (Hidaka & Yamazato 1982, Muko et al 2000 only occurred at the shallow stations. Goh et al (1994) concluded that light was the primary factor controlling colony form in their study of depth-related coral morphology on reefs around Singapore, including the reefs examined in this paper.…”

Section: Environmental Factorsmentioning

confidence: 55%

Genotype × environment interactions in transplanted clones of the massive corals Favia speciosa and Diploastrea heliopora

Todd¹,

Ladle²,

Lewin-Koh³

et al. 2004

Mar. Ecol. Prog. Ser.

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Environment-dependent variation in the morphological, physiological, or behavioural expression of a genotype is termed phenotypic plasticity. To test for small-scale morphological plasticity in the Indo-Pacific massive corals Favia speciosa (Dana, 1846) and Diploastrea heliopora (Lamark, 1816), fragments (clone-mates) from 12 colonies of each species were reciprocally transplanted among 6 new habitats located within 2 environmental gradients: a depth cline and a nearshore-to-offshore gradient in sedimentation rates and total suspended solids (TSS). After 7 mo, all fragments were collected, cleared of tissue, and 10 morphometric characters extracted from randomly chosen corallites. Reaction norms, analysis of variance, and canonical discriminant analysis describe environmentinduced changes in corallite architecture. These changes are more pronounced in the depth cline than along the sediment gradient. Similarity of response is suggested by exploratory factor analysis where, for both species, size attributes dominate the first factor, antisymmetry the second, and corallite exsertion the third. Highly significant genotype × environment interactions for F. speciosa indicate that, for this species, genotypes vary in the level of plasticity expressed. Light and TSS emerge as the primary correlates influencing morphological change, although other parameters might act additively, synergystically or antagonistically with them. In shallow waters, increased corallite exsertion may enhance light capture or, alternatively, protect the central (oral disc) area of each polyp from harmful UV radiation. Morphological variability, combined with environment-induced changes in pigmentation, could impede accurate identification of these taxa.

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Incorporation of strontium (⁹⁰Sr²⁺) into the skeleton of the hermatypic coral Galaxea fascicularis

Krishnaveni

1991

J. Exp. Zool.

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The rate of 90Sr2t deposition in Galaxea fascicularis was linear with respect to Sr2+ concentration (0.01-20 mM) and refractory to DCMU (1 pM), a n inhibitor of photosynthesis. The deposition rate of "Sr2+ in polyps incubated under a light intensity of 200 pE.m-2.s-2 was not significantly different from that in polyps incubated in total darkness. The deposition rate of 45Ca2+ (1-20 mM), on the other hand, exhibited saturation kinetics. In addition, i t was DCMU sensitive and enhanced by light. Our results therefore support observations reported elsewhere that K, : is inversely correlated with growth rate in reef corals. However, Sr2+ and Ca2+ deposition in G. fascicularis does not appear to involve similar biochemical mechanisms.

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Intraspecific interactions in a scleractinian coral, Galaxea fascicularis: Induced formation of sweeper tentacles

Cited by 50 publications

References 18 publications

Sweeper tentacles of the brain coral Platygyra daedalea: induced development and effects on competitors

Sweeper tentacles of the brain coral Platygyra daedalea: induced development and effects on competitors

Genotype × environment interactions in transplanted clones of the massive corals Favia speciosa and Diploastrea heliopora

Incorporation of strontium (⁹⁰Sr²⁺) into the skeleton of the hermatypic coral Galaxea fascicularis

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Intraspecific interactions in a scleractinian coral, Galaxea fascicularis: Induced formation of sweeper tentacles

Cited by 50 publications

References 18 publications

Sweeper tentacles of the brain coral Platygyra daedalea: induced development and effects on competitors

Sweeper tentacles of the brain coral Platygyra daedalea: induced development and effects on competitors

Genotype × environment interactions in transplanted clones of the massive corals Favia speciosa and Diploastrea heliopora

Incorporation of strontium (90Sr2+) into the skeleton of the hermatypic coral Galaxea fascicularis

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Resources

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Incorporation of strontium (⁹⁰Sr²⁺) into the skeleton of the hermatypic coral Galaxea fascicularis