Structures associated with feeding in three broad-mouthed, benthic fish groups

The flatheads, toadfishes, and goosefishes discussed here hold certain features in common. All are bottom-living forms with depressed head areas and broad gapes, and all eat large food items: fishes and/or crabs. All have developed structural specializations in association with this diet. The three groups are at most distantly related, and their feeding specializations are different and have evolved from different bases. In flatheads the combination of large food items and depressed head regions seems to have led to the separation of the two halves of the pelvic girdle, a feature in which they differ from their scorpaenoid relatives. Toadfish peculiarities associated with feeding are various but most notable in those that pass crabs they eat through the gape and into the mouth. Goosefish feeding is centered around the use of a lure to attract prey to within striking distance. The three fish groups are discussed separately, but their feeding structures are compared to one another in the final section of the paper.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42639/1/10641_2004_Article_BF00005053.pd

One sixth of Amazonian tree diversity is dependent on river floodplains

Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.Naturali

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

General Ecology of Six Species of Hawaiian Cardinalfishes

Six species of cardinalfishes (Pisces: Apogonidae) are found together in shallow marine waters of Hawaii day and night. All six species remain in holes and caves during the day and emerge at night when they feed. The centers of abundance, ecological ranges, and other requirements of the six species differ during their life histories. During the day, Foa brachygramma is found in crevices or rubble on shallow, calm reef flats and unlike the other species may enter areas of low salinity and poor circulation. Young Foa are found under ledges in deeper water than are adults. Apogon menesemus is most abundant in clear, relatively deep water, especially where the substrate is almost completely covered by live coral. It lives at the back of holes or caves. Apogon erythrinus frequently inhabits small, dark holes in either dead coral heads or basalt cliff caves. Apogonichthys waikiki is most often found in pairs in large, widely spaced living coral heads. Apogon maculiferus adults are found under ledges and in caves at depths of over 20 meters. Young A. maculiferus aggregations are found in shallow water under ledges or at cave entrances. Apogon snyderi has the widest habitat distribution, although it is restricted to substrates with some sand. It lives in the middle of caves close to the floor, and under rubble, coral heads, or ledges. Each species reacts differently to increasing or decreasing light levels. Generally, a species' response to a given amount of light in the laboratory is similar in the field. In shallow water, adult Apogonichthys waikiki is not seen outside holes unless light intensity is less than 1.75 fc. Apogon erythrinus emerges or enters holes at about ±5 fc, A. menesemus at about 16 fc, and A. snyderi at about 88 fc. Adult Foa brachygramma leaves or enters cover at about 2400 fc, young Foa at about 700 fc. Adult Apogon maculiferus emerge and enter cover at about 100 fc and young A. maculiferus at about 2700 fc. Diurnal predators remove more individuals of species living in brighter light intensities; cavedwelling predators remove those living in lower light intensities. At night all species are opportunistic carnivores on zooplankton and benthic invertebrates, but there are differences in their foraging locations. Apogon snyderi and A. maculiferus forage mostly over light-colored substrates, but A. maculiferus feeds nearer dawn, higher in the water, in aggregations, and closer to large objects than does A. snyderi. Apogon erythrinus is found no more than 3 cm from hard substrates, vertical and horizontal. The other three species are found near large underwater objects. Foa brachygramma remains near the bottom when there is a current, and groups of fish rise in the water column on quiet nights when there is a half to full moon. Apogon menesemus is most often found in midwater and is often located in the shadow of large underwater objects on moonlit nights. Apogonichthys waikiki hovers near holes in the isolated coral heads where it is found diurnally. Nocturnal predators take individuals of all species except A. waikiki

Deep-sea Benthic Fish of the Hawaiian Archipelago, Cross Seamount, and Johnston Atoll

More than 250 benthic fish taxa were photographed and videotaped by Hawaii Undersea Research Laboratory submersibles at depths between 40 and 2000 m in the Hawaiian Archipelago, Johnston Atoll, and Cross Seamount. Most of the 213 identified fish species occurred close to hard substrates with holes, ledges, or caves. Twenty-two species (notably the larger sharks, lutjanids, and carangids) are cosmopolitan. Seventy-six species are restricted to various Indo-Pacific areas, 64 in the Pacific, and 51 in the Hawaiian Archipelago including Cross Seamount and Johnston Atoll. There is a rapid decrease in the number of species from 200 to 400 m depth. One hundred eight species were seen 20 m deeper than previously reported. Eleven of the deeper-dwelling animals were found 20 m shallower than previously recorded. Faunal zones were not recognized at any depth. Species newly recorded in Hawai'i include Bathypterois grallator (Goode & Bean), Bodianus cylindriatus (Tanaka), Centrophorus cf. granulosus (Bloch & Schneider), Chaunax fimbriatus Hilgendorf, Caelorinchus spilonotus Sazonov & Iwamoto, Notocanthus sp., Paratrachichthys prosthemius Jordan & Fowler, Prognathodes guezei (Mauge & Bauchot), and Sladenia remiger Smith & Radcliffe. New species collected and reported elsewhere are Centrodraco rubellus Fricke et al., Epigonus glossodontus Gon, Owstonia sp., and Pseudanthiasfucinus (Randall & Ralston). Caelorinchus sp. 2 and Callanthias sp. are probably undescribed. It appears that the Hawaiian deep-sea fish fauna has multiple origins and affinities with many regions

Ecological Aspects of the Distributions of Fishes at Fanning Island

The nearshore marine environment of Fanning Island (30 55' N, 159 23' W) was subjectively partitioned into seven habitats which are briefly described. Efforts were made to sample in each in order to obtain as complete as possible a record of the fish species present. Observations were made underwater by skin and SCUBA diving during July-August 1972, and April 1973; 214 species of fishes (96 genera in 37 families) were seen. Tables provide semiquantitative abundance estimates for each species in every habitat, and a list of characteristic species associated with various substrates within the habitats. Semiquantitative abundance estimates were used to generate diversity estimates and two measures of faunal resemblance for the habitats taken two at a time. Relationships between the faunas of the different habitats were used to generate hypotheses about ecological relationships between habitats. It is argued that strong surge and tidal currents strongly influence the distributions of Fanning Island fishes, separating outer reef fishes from lagoon fishes by a rich zone associated with the English Harbor channel. Our observations include the addition of 57 species to the Line Islands fish fauna. Their zoogeographical affinities support an earlier determination of a central Pacific character for the Line Islands fishes

First Record of the Chaetodontid Genus Prognathodes from the Hawaiian Islands

A total of 32 individuals of a chaetodontid fish resembling Prognathodes guezei (Mauge & Bauchot) were recorded on photographs and videotape taken from the Hawaii Undersea Research Laboratory's deep-sea submersibles Makali'i and Pisces-V between 1982 and 1990. These sightings represent the first record of the genus Prognathodes from the Hawaiian Islands. The fish were observed at depths of 106-187 m off Hawai'i, at Penguin Bank, and at French Frigate Shoals (Northwestern Hawaiian Islands). Most sightings were made on the western side of Hawai'i, particularly near Kealakekua Bay