Skip to main content
eScholarship
Open Access Publications from the University of California

UCB Moorea Class: Biology and Geomorphology of Tropical Islands is an intensive field course (13 units), taught every Fall semester by UC Berkeley. A highly selective group of 20-22 undergraduate students spend a month on campus in Berkeley for lectures and labs five days a week, then go to the Richard Gump Biological Station on the island of Moorea in French Polynesia for nine weeks to carry out an intensive research project and to do some general educational field trips and labs, supervised by a number of professors and graduate student instructors. They learn all the stages of scientific research from conception of a project to giving talks and and writing. These papers are the result of their research.

Cover page of Distribution, Ecology, and Systematics of the Filmy Ferns (Hymenophyllaceae) of Moorea, French Polynesia

Distribution, Ecology, and Systematics of the Filmy Ferns (Hymenophyllaceae) of Moorea, French Polynesia

(2006)

Ferns present an interesting case in island biogeography because of their unusually high dispersal ability. A general survey of the filmy ferns (Hymenophyllaceae) of Moorea, French Polynesia was undertaken by observing distribution in the field, conducting tests of desiccation tolerance, and inferring a phylogeny based on morphological characters. A total of 12 filmy fern species (including three species previously unreported in the literature for Moorea) were found to occur in moist, wellcovered habitats throughout the island, with distinct sets of high elevation and low elevation species. Five species were included in an experiment to determine relative degree of desiccation tolerance; results indicate that terrestrial species have lower desiccation tolerance than epiphytic or epipetric species. In order to place the Moorea filmy ferns in the larger archipelago context, eight additional Society Island species were included in the phylogeny for a total of 20 taxa based on 21 morphological characters; interspecies relationships reflect the taxonomy of Hymenophyllaceae sensu lato. Filmy fern species are widely dispersed throughout the Society Islands, and there is no indication of an adaptive radiation on Moorea.

Cover page of Feeding Preference of the Cushion Star, Culcita Novaeguineae in Mo’orea

Feeding Preference of the Cushion Star, Culcita Novaeguineae in Mo’orea

(2006)

Previous studies of the feeding biology of Culcita novaeguineae Muller & Troschel in Hawai’i have shown that the cushion star prefers to prey on coral species of the genus Pocillopora over the genus Porites. Distribution and feeding biology studies of C. novaeguineae in Cook’s Bay on the island of Mo’orea, French Polynesia have shown that it habitats near Porites spp. coral in areas where Porites spp. coral is sparse, and prefers to prey on Acropora spp. coral. The purpose of this study was to further examine coral prey preference of C. novaeguineae in Mo’orea, using specimens from four areas on the island for better representation of its feeding ecology on Mo’orea, French Polynesia. My studies showed that C. novaeguineae in Mo’orea prefers Acropora spp. and Pocillopora spp., over Porites spp. (p=0.0046), and showed no preference for Acropora spp., over Pocillopora spp.. The study further determined that C. novaeguineae primarily feeds nocturnally, and moves persistently in search for food. As a coral predator, C. novaeguineae can affect abundance of certain coral species, and change the overall reef ecology in Mo’orea.

Cover page of Distribution and Dispersal of the South Pacifc Tree, Fagraea Berteriana (Loganiaceae)

Distribution and Dispersal of the South Pacifc Tree, Fagraea Berteriana (Loganiaceae)

(2006)

Tahitian legend states Fagraea berteriana is a gift of repentance from the god, Tane. The scientific community knows little more about this tree than its inter-island distribution in the South Pacific. I surveyed the island of Moorea to map an intra-island distribution of F. berteriana and quantify environmental characteristics surrounding the tree’s growth. I tested dispersal hypotheses by collecting bird observations and conducting seed germination experiments that included a numer of seed scarification treatments. The tree occurred in densities ranging from 44 to 244 trees/hectare and at elevations spanning from approximately 300 to 900 m. Density differed with significance between two sites, Tohiea and the Cross Island Trail. Tree density increased with greater elevations and more southerly aspects. Ninety-five percent of the trees sampled grew on slopes greater than 80%. There was no correlation between tree density and slope or between density and tree height. Tree density did not significantly differ between three substrate types: rock, rocky soil, and soil. I observed Silvereyes and Red-vented bulbuls consuming F. berteriana fruits and germination from seeds, although at a less than 1% rate. The germination success and bird observations served as a preliminary investigation of the dispersal of F. berteriana and fostered ideas concerning worthwhile future directions of study.

Cover page of Ontogeny of Defense : Does Life History Affect Predator Response Behavior in the Pygmy Octopus, Octopus Bocki?

Ontogeny of Defense : Does Life History Affect Predator Response Behavior in the Pygmy Octopus, Octopus Bocki?

(2006)

Organisms experience physiological and ecological changes during ontogenesis, and studies have shown that such changes have an impact on behavior over the life cycle. However, little is known about how octopus behavior changes during ontogeny. The pygmy octopus, Octopus bocki (Adam 1941), expresses differences in chromatophore development and mantle length between developmental stages. These changes may be important in predator defense, therefore I hypothesized that predator response behavior also changes over the life cycle. Timed interactions between an octopus and a fish predator were used to compare the behaviors and color displays exhibited by three different size categories of O. bocki; juvenile, sub-adult, and adult. Color display diversity was analyzed using the Shannon-Weiner diversity index. The analysis revealed a negative correlation between color display diversity and size during predator interactions, supporting the hypothesis that behavior changes over the life cycle. Counter-intuitively color display diversity decreases while chromatophore development increases. To broaden the context in which behavior was examined, interactions between adult O. bocki were used to investigate how adults use color displays. The number of color/texture combinations was graphed to compare displays expressed during predator interactions with those expressed during intraspecific interactions. A Wilcoxon test revealed that adult O. bocki used significantly more color and texture displays during intraspecific interactions than during predator interactions. I concluded that adult octopuses use color displays for communication rather than predator defense and that these displays change during ontogenesis.

  • 1 supplemental PDF
Cover page of Insect Biodiversity and Assessment of Herbivory in Native and Non-Native Plants in Mo’orea, French Polynesia

Insect Biodiversity and Assessment of Herbivory in Native and Non-Native Plants in Mo’orea, French Polynesia

(2006)

The objective of this study was to determine if the distribution of insect species and presence of herbivory differed between native and non-native plants in the coastal region of Mo'orea, French Polynesia. Therefore, four native plant species (Barringtonia asiatica, Hibiscus tiliaceus, Terminalia catappa, Thespesia populnea) and four non-native plant species (Carica papaya, Mangifera spp., Morinda citrifolia, Musa spp.) were sampled. Each collected insect was tested for herbivory, and placed in a cup with a 2X1in. piece of undamaged leaf from the tree it was found and frequently checked for damage. Significantly greater insect species abundance was found on native plants compared to non-native plants (p=0.0431). No significant difference was found in richness (p=0.6409) or diversity (p=0.8451) between native and non-native plants. Significantly more herbivory damage was observed on the whole tree in native plants (p=0.0001). The herbivory trials found more cases of herbivory damage in non-native plants compared to native plants, 14 cases and 10 cases respectively, but more total area damaged in native plants compared to non-native plants, with 5.015% and 4.18% damage respectively. No significant differences were found between abundance and height of sampling, richness and height of sampling, or diversity and height of sampling (p=0.1108, 0.0933, and 0.07695). No significant differences were found between abundance and tree height, richness and tree height, or diversity and tree height (p=0.5305, 0.6156, 0.7805). The results show that there is more insect abundance and more herbivory damage in native plants, suggesting that generalist herbivores are feeding on non-native plants while specialist and generalist herbivores are feeding on native plants.

Cover page of Does the River Continuum Concept Work in Small Island Streams? Functional Feeding Group Variation Along a Longitudinal Gradient

Does the River Continuum Concept Work in Small Island Streams? Functional Feeding Group Variation Along a Longitudinal Gradient

(2006)

The River Continuum Concept (RCC) predicts that as the form of particulate organic matter available in streams and rivers varies longitudinally, so will the functional feeding groups (FFGs) of benthic macroinvertebrates. The RCC was developed based on data from continental streams; therefore, its applicability to the unique ecology of island streams is virtually untested. The purpose of this study was to discover if the RCC works in the small streams of Moorea, French Polynesia. Three sites along an elevational gradient were sampled for benthic macroinvertebrates in five streams of similar catchment size. Each sample was sorted and all taxa were assigned to a FFG. Species richness and FFG variation along a longitudinal gradient were compared to RCC predictions. Patterns in the longitudinal variation of crustacean/mollusc species richness and shredder, grazer, and predator percent composition were found to match RCC predictions. However, total species richness, insect species richness, and the percent composition of collecting organisms did not. Therefore, an alternative theoretical framework is needed to accurately describe FFG variation in tropical streams.

Cover page of Christmas Colors : Colormorph Distribution of Spirobranchus Giganteus Pallas 1766 on Moorea, French Polynesia

Christmas Colors : Colormorph Distribution of Spirobranchus Giganteus Pallas 1766 on Moorea, French Polynesia

(2006)

Spirobranchus giganteus Pallas 1766 is an obligate associate of coral. This study focused on the distribution of five branchial crown colormorphs (Blue, Brown, Marigold, Purple, and White) on eight coral species (Acropora I, Acropora II, Porites I, Porites II, Porites III, Porites IV, Porites V, Porites VI) by quadrat sampling method. White was the most abundant colormorph, representing 24.0% of the total. Blue was the least abundant colormorph at 9.5% of the total. There were no significant differences in Shannon-Weiner Diversity Index (H’) of colormorphs between coral species. Also, relative colormorph abundance did not differ significantly between coral species or between the Front and Back positions. Only Blue and Marigold differed significantly in relative abundance between Top, Midde, and Bottom positions. Findings support a colormorph distribution of colormorphs. There are two possible explanations: 1) mortality and selection effects on distribution and 2) phenotypic plasticity, a combination of genetic and environmental factors contributing to the occurrence of certain phenotypes.

Cover page of Is the Tamanu Losing Turf? DIstribution and Propogation of the Economically Important Calophyllum Inophyllum of Moorea

Is the Tamanu Losing Turf? DIstribution and Propogation of the Economically Important Calophyllum Inophyllum of Moorea

(2006)

French Polynesia’s indigenous tamanu Tree (Calophyllum inophyllum) is an important natural resource harvested for lumber, resin, and oil. Being a marine-seed dispersed species it self-propagates and can be found growing along the coastline of Moorea. Development and harvest patterns on Moorea may be slowing the natural reproductive rate of the species. Fifty years ago it was recommended as a species to include in management programs as it had been noted to be in decline due to its slow growth and high use rates. Interviews with elders, carvers and healers indicated that the range has indeed diminished. A total island survey was performed and the resulting map of C. Inophyllum’s distribution indicates that the range is healthy- but it will continue to compete with human development for the diminishing resource of coastal terrain.

Cover page of Function, Design, Scaling, and Sexual Differences of Dimorphic Chelae in the Land Crab, Cardisoma Carnifex

Function, Design, Scaling, and Sexual Differences of Dimorphic Chelae in the Land Crab, Cardisoma Carnifex

(2006)

Crab chelae are a model system for studying the relationship between the biomechanics of an organism’s structure and its ecolgical role. This study investigated how chelae dimorphism may correlate with specialization in function in the land crab Cardisoma carnifx (Herbst 1791). This was achieved by comparing field observations of preferential claw usage during diurnal activities to a mechanical model drived from anatomical claw measurements, claw closing effort of captured specimens, and calculations of expected closing force. Behavior, mechanical scaling, and effort were also compared between males and females. Foraging, eating, and lead claw entering burrow showed significant differences in claw use frequency. It was also found that the major and minor claws scaled differently with respect to carapace length, with the major claw displaying positively allometric scaling and the minor claw displaying near-isometric scaling. Measurement of claw closing effort with respect to claw length showed high correlation in male minor and female major claws. In males, expected force measurements showed a greater rate of growth in the minor claw than in the major claw with respect to claw lengh, but in females, expected force in the major claw exhibited a greater rate of growth. A possible explanation for the differences in design between sexes may be that there are functional differences between male nd female chelae, such as the primary use of male minor claw and female major claw in gripping objects when stressed.

Cover page of Predator Defense Mechanisms in Shallow Water Sea Cucumbers (Holothuroidea)

Predator Defense Mechanisms in Shallow Water Sea Cucumbers (Holothuroidea)

(2006)

The various predator defense mechanisms possessed by shallow water sea cucumbers were surveyed in twelve different species and morphs. While many defense mechanisms such as the presence of Cuverian tubules, toxic secretions, and unpalatability have been identified in holothurians, I hypothesized that the possession of these traits as well as the degree to which they are utilized varies from species to species. The observed defense mechanisms were compared against a previously-derived phylogeny of the sea cucumbers of Moorea. Furthermore, I hypothesized that while the presence of such structures is most likely a result of the species’ placement on a phylogenetic tree, the degree to which they utilize such structures and their physical behavior are influenced by their individual ecologies. The presence of a red liquid secretion was restricted to individuals of the genus Holothuria (Linnaeus 1767) however not all members of the genus exhibited this trait. With the exception of H. leucospilota, which possessed both Cuverian tubules and a red secretion, Cuverian tubules were observed in members of the genus Bohadschia (Ostergren 1896). In accordance with the hypothesis, both the phylogenetics and individual ecology appear to influence predator defense mechanisms. However, even closely related species of similar ecology may differ considerably.