Hawaiian Coral Reef Research Articles

Juvenile Groups in a Coral‐Reef Damselfish: Density‐Dependent Effects on Individual Fitness and Population Demography

Costs and benefits to group living in animals may affect the fitness of individual group members and also demography of the population. The effects of grouping on the growth, survival, and attainment of maturity of juveniles of an Hawaiian coral—reef damselfish (Dascyllus albisella) were evaluated from 1987 through 1989. In this species, pelagic larvae settle (at °14 mm total length) on coral heads, joining temporary groups of up to 15 juveniles. Groups members establish a dominance hierarchy based on size, and fish leave these groups upon reaching mature size (70 mm total length) to enter the nearby adult population. Previously, I had demonstrated that larvae preferentially join larger groups and I expected to find clear advantages to group membership. Survival, especially of smaller fish, was enhanced in large groups, but growth, especially by individuals of low social status, was reduced. Consequently, the time to reach maturity increased with group size in both years of the study, suggesting a more rapid entry into the adult population of fish in smaller groups or living alone. However, the probability of reaching mature size (a function of size—specific growth and survival) increased with group size in 1988 but not in 1987, thus indicating a benefit to group living during only one of the two years of the study. Although this study demonstrated density—dependent juvenile growth and survival, with consequent fitness effects of group living, it has also highlighted considerable inter— and intra—annual variability in these relationships. Such variability will have major consequences for predictions of the effects of juvenile ecology on the demography of organisms.

GENOTYPIC VARIATION AND CLONAL STRUCTURE IN CORAL POPULATIONS WITH DIFFERENT DISTURBANCE HISTORIES.

Genotypic diversity in six populations of the endemic Hawaiian reef coral, Porites compressa, was directly related to habitat-disturbance history. The highest diversity (lowest amount of clonal proliferation) was found in populations that had been intensely or recently disturbed. In these populations, space was not limited and mean colony size was small (< 500 cm2 ), suggesting early stages of recolonization. In an undisturbed, protected habitat, lower genotypic diversity was a result of a significant degree of clonal replication of established genotypes. Unoccupied substratum was rare in this habitat, and average colony size was large (> 2500 cm2 ). Populations in intermediately disturbed habitats showed intermediate levels of diversity and clonal structure as a result of the combined contributions of sexual and asexual reproduction. Individual clones were distributed over small areas (< 4 m2 ) or distances (< 1 m) in young populations, and more broadly (> 256 m2 ) and over longer distances (> 90 m) in the older, undisturbed population. Interpretations of life-history parameters and estimates of total genetic variability in species that have the potential to reproduce asexually are dependent upon an assessment of the overall clonal structure of populations. The power of genotypic assays to reliably detect clonal versus unique colonies, as well as the spatial scales over which clonal populations are sampled, are critical to such assessments.

Colonization of Hawaiian reef corals on new and denuded substrata in the vicinity of a Hawaiian power station

The colonization and growth of reef corals settling on new substrata (concrete and basalt) and on a denuded coral reef were studied over a seven-year period. The study area is in the vicinity of an outfall discharging thermal effluent from a Hawaiian power station, and both numbers and coverage of settled corals were found to increase exponentially with proximity to the outfall's discharge. Recruitment rates adjacent to the outfall were at least ten times greater than values previously reported for open ocean areas in Hawaii, and the estimated time for recovery of the coral community near the outfall was comparable to the most rapid that has been reported worldwide. By contrast, coral recruitment and recovery more distant from the outfall compared well with slower rates reported for other areas in Hawaii. Entrainment of coral planulae in water discharged into the area by the outfall is proposed to be the principal mechanism promoting the high coral colonization.

Wave stress and coral community structure in Hawaii

The most significant factor determining the structure of Hawaiian reef coral communities is physical disturbance from waves. Sequential analysis of community structure off the west coast of the island of Hawaii shows that variation of wave energy and storm frequency clearly affects organization in time and space. Normal conditions of low wave stress maintain four well-defined reef zones; diversity is highest at intermediate depths and decreases in physically rigorous shallow areas and stable deep reef slopes. Intermediate level storm wave events cause variable effects within the reef zones, but the zonation pattern, as a whole, is maintained. Diversity increases in zones that are dominated by a single species largely through nonlethal fragmentation and transport, but decreases in the zone of most equitable species distribution. Conversely, severe infrequent storm disturbances that cause massive mortality to all coral species wipe out the pattern of community structure and return the entire community to a low diversity early successional stage.

Estimating the daily contribution of carbon from zooxanthellae to coral animal respiration1

An equation is derived which rigorously defines the photosynthesis: respiration ratio (P:R) for any alga: invertebrate symbiotic association arid permits the computation of the fractional contribution of translocated algal carbon to the daily respiratory carbon requirement of the host animal. The equation is applied to two species of symbiotic reef corals, using O2 flux data from 24‐h continuous measurements in situ. Given certain assumptions, the algae in the shallow‐water Hawaiian reef corals Pocillopora damicornis and Fungia scutaria can supply of the order of 63 and 69% of the daily respiratory carbon demand of their respective animal hosts.

Effects of water motion on reef corals

The Hawaiian reef coral Pocillopora meandrina Dana is restricted to turbulent environments. P. damicornis (L.) is most abundant on semi-protected reefs, while Montipora verrucosa (Lamarck) is characteristic of very calm environments. These species were grown in the laboratory under various conditions of water motion. Water motion influenced the growth, mortality, and reproductive rate, of each species differently. The differences may be attributed to morphological adaptations of the corals to their normal hydrodynamic environment. Water motion appears to influence corals by controlling the rate of exchange of material across the interface between the sea water and the coral tissue.

Effects of temperature on the mortality and growth of Hawaiian reef corals

Three common species of Hawaiian reef corals, Pocillopora damicornis (L.), Montipora verrucosa (Lamarck) and Fungia scutaria Lamarck, were grown in a temperature-regulated, continuous-flow sea water system. The skeletal growth optimum occurred near 26°C, coinciding with the natural summer ambient temperature in Hawaii, and was lowest at 21° to 22°C, representing Hawaiian winter ambient. Levels of approximately 32°C produced mortality within days. Prolonged exposure to temperatures of approximately 30°C eventually caused loss of photosynthetic pigment, increased mortality, and reduced calcification. Corals lived only 1 to 2 weeks at 18°C. The corals showed greater initial resistance at the lower lethal limit, but ultimately low temperature was more deleterious than high temperature. Results suggest that a decrease in the natural water temperature of Hawaiian reefs would be more harmful to corals than a temperature increase of the same magnitude.

A Numerical Taxonomic Study of Caribbean and Hawaiian Reef Corals

Powers, Dennis A. and F. James Rohlf (Division of Biological and Medical Research, Argonne National Laboratory, Argonne, Ill. 60439, and Division of Biol., State Univ. of New York, Stony Brook, N. Y. 10960) 1972. A numerical taxonomic study of Caribbean and Hawaiian reef corals. Syst. Zool., 21:53-64.-Sixty characters were measured and used in multivariate statistical programs to study the systematics of 54 species of Caribbean and Hawaiian reef corals. Correlation and distance phenograms and a computer-generated, threedimensional model were used to develop phenetic rankings of species groups at levels corresponding to the taxonomic categories of genus, family and suborders. The data generally supports the classification of Vaughan and Wells (1943) as opposed to the classical systematics (e.g., Hyman, 1940; Bourradaile, et al., 1963) of the order. [Numerical taxonomy; reef corals; Caribbean; Hawaii.]

A Numerical Taxonomic Study of Caribbean and Hawaiian Reef Coral

A Numerical Taxonomic Study of Caribbean and Hawaiian Reef Coral

Food Specialization in Conus in Hawaii and California

The 6—11 vermivorous species of the marine gastropod genus Conus co—occurring on Hawaiian coral reefs and intertidal benches have specialized diets, as measured by prey species redundancy; each feed primarily on a different species, or group of species. In contrast, C. californicus has no co—occurring as potential competitors for food and its diet, comprising members of six classes in four animal phyla, is the most diverse known for any species of Conus. Prey species redundancy of the one common molluscivorous species in Hawaii is intermediate between values for the Hawaiian vermivores and C. californicus.

Primary productivity of an Hawaiian coral reef: A critique of flow respirometry in turbulent waters : Gordon M. S. and H. M. Kelly, 1962. Ecology, 43 (3): 473–480.

Primary productivity of an Hawaiian coral reef: A critique of flow respirometry in turbulent waters : Gordon M. S. and H. M. Kelly, 1962. Ecology, 43 (3): 473–480.

Skeletal organization in the coral, Pocillopora damicornis

ABSTRACT The skeleton of this Hawaiian reef coral was found to contain at least 99’9% by weight of the mineral aragonite, present as submicroscopic crystals in spheritic arrangements. The organic component of the skeleton comprises 0·01 to 0·1 % of the total weight and has 3 microscopic constituents: (1) filaments of lime-boring algae, (2) a dispersed network of fibres 1 μ in diameter, and (3) a transparent, milky, regionally biréfringent matrix of chitin. The chitin was observed to be a spongework of fibrils of average diameter 20 mμ. The chitin fibrils were inferred to be randomly oriented in the plane of the skeletogenic epithelium perpendicular to the direction of growth of the long axes of the aragonite crystals. The development of the skeleton is traced from the initial mineral deposit by the larva after its attachment, through the formation of the larval skeleton and growth into the fully formed, branching colony. The process of formation of chitin fibrils according to the contour of the skeletogenic epithelium and the later deposition of aragonite crystals as described accounts for the formation of all skeletal elements of Pocillopora. Evidence is presented for the hypotheses that (1) the amide group of the chitin molecule is responsible for the ability of certain organic substrates to be calcified (thus protein is not a necessary component of such substrates); (2) zooxanthellae in Pocillopora contribute a product of photosynthesis to the coral as the monomer of the chitin matrix; and (3) chitin synthesis thus depends on the activity of zooxanthellae and the rate of chitin synthesis controls the rate of skeletogenesis in Pocillopora.

Primary Productivity of an Hawaiian Coral Reef: A Critique of Flow Respirometry in Turbulent Waters

Among the variotus problems posed to marine biologists by the existenice of coral reefs, one of the most interesting has been that of how to estimate the overall metabolic rate of such large and lush communities. Direct approaches to this problem have been made only within the past 15 years, the basic technique being the use of the water flowing across the reef as a respirometer. The general conclusion to date is that coral reefs are among the most productive of marine comnmunities anid that they are, barring a single possible exceptioin, self-supporting (autotrophic) communities (Kohn and Helfrich 1957, Odum et al. 1959, Odum and Odum 1955, Sargent and Austin 1949, 1954). Each successive study of this problem has produced data of increased reliability. The principal theoretical development producing this increase in reliability has been greater awareness of the extent and importance of oxygen exchanges across the air-sea interface between observation stations. Onlv Kohn and H-elfrich (1957) and Odum et al. (1959) explicitly take these exchanges into account. Even these authors, however, base their estimiiates of the magnitude of these exchanges on the simplified formulation of the problem presented by Odum (1956) and Odum and Hoskin (1958). These simplified calculations omit the important effects on air-sea gas exchanges of the slhort-term temporal variations in surface turbuilenlce which usuially occur in the water flowing over the reef. The present paper describes the results of a new study of coral reef productivity as estimated by chatnges in oxygencontent in the water flowing over an Hawaiian coral reef. Figures for total reef community photosynthesis and respiration are calculated using both the simplified technique

A Survey of the Hawaiian Coral Reefs

A Survey of the Hawaiian Coral Reefs

Studies Upon the Biological Significance of Animal Coloration. II. A Revised Working Hypothesis of Mimicry

Next article FreeStudies Upon the Biological Significance of Animal Coloration. II. A Revised Working Hypothesis of MimicryW. H. LongleyW. H. Longley Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 51, Number 605May, 1917 Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/279604 Views: 189Total views on this site Citations: 5Citations are reported from Crossref PDF download Crossref reports the following articles citing this article:Adam M. M. Stuckert, Mathieu Chouteau, Melanie McClure, Troy M. LaPolice, Tyler Linderoth, Rasmus Nielsen, Kyle Summers, Matthew D. MacManes The genomics of mimicry: Gene expression throughout development provides insights into convergent and divergent phenotypes in a Müllerian mimicry system, Molecular Ecology 30, no.1616 (Jul 2021): 4039–4061.https://doi.org/10.1111/mec.16024T. Bonacci, A. Mazzei, A. Naccarato, R. Elliani, A. Tagarelli, P. Brandmayr Beetles “in red”: are the endangered flat bark beetles Cucujus cinnaberinus and C. haematodes chemically protected? (Coleoptera: Cucujidae), The European Zoological Journal 85, no.11 (Mar 2018): 128–136.https://doi.org/10.1080/24750263.2018.1449906Tim Caro, Karrie Beeman, Theodore Stankowich, Hal Whitehead The functional significance of colouration in cetaceans, Evolutionary Ecology 25, no.66 (Apr 2011): 1231–1245.https://doi.org/10.1007/s10682-011-9479-5Justin Marshall, Sönke Johnsen Camouflage in marine fish, (Jul 2011): 186–211.https://doi.org/10.1017/CBO9780511852053.011N. J. Marshall, K. Jennings, W. N. McFarland, E. R. Loew, G. S. Losey, W. L. Montgomery Visual Biology of Hawaiian Coral Reef Fishes. II. Colors of Hawaiian Coral Reef Fish, Copeia 2003, no.33 (Sep 2003): 455–466.https://doi.org/10.1643/01-055

Pleistocene glaciation and the coral reef problem

This paper briefly mentions Pleistocene glaciation on Mauna Kea. Daly hypothesizes that the present Hawaiian coral reefs began their growth in post-glacial time.