Pacific Science, Volume 30, Numbers 1-4, 1976

Revision of the Genus Pandanus Stickman. Part 40 The Fijian Species of the Section Pandanus

St. John, Harold — Thu, 01 Jul 1976 00:00:00 GMT

The Diets of Sula dactylatra, Sula sula, and Fregata minor on Christmas Island, Pacific Ocean

Schreiber, Ralph W; Hensley, Dannie A — Thu, 01 Jul 1976 00:00:00 GMT

The diets of the Blue-faced Booby (Sula dactylatra), the Red-footed Booby (Sula sula), and the Great Frigatebird (Fregata minor) were studied by analyses of reg urgitation samples. Flying fish and squid composed the majority of the diets, but the Frigatebirds also consumed numerous Sooty Tern (Sterna fuscata) pulli. These data allow comparison with similar earlier studies of the smaller bird species that inhabit the atoll and indicate that resource partitioning occurs through the percentage of fish and squid taken and the size of the prey items taken, with the larger species of birds eating larger fish and squid.

Redescription of Antipathes panamensis Verrill (Coelenterata, Antipatharia)

Opresko, Dennis M — Thu, 01 Jul 1976 00:00:00 GMT

Early Life History of the Giant Clams Tridacna crocea Lamarck, Tridacna maxima (Roding), and Hippopus hippopus (Linnaeus)

Jameson, Stephen C — Thu, 01 Jul 1976 00:00:00 GMT

Giant clams may be stimulated to spawn by the addition of macerated gonads to the water. Individuals of Tridacna maxima collected at Anae Island, Guam, spawned from November to March. On Palau, Hippopus hippopus spawned in June and Tridacna crocea, in July. Tridacna crocea, T. maxima, and H. hippopus displayed a stereotyped development pattern in morphogenesis and rate of development. Fertilized eggs of T. crocea, T . maxima, and H. hippopus had mean diameters of 93.1, 104.5, and 130.0 um, respectively. The day-2 straight-hinge veligers of T. crocea, T. maxima, and H. hippopus had mean shell lengths of 155.0, 168.0, and 174.4 pm, respectively. Settlement occurred 12, 11, and 9 days after fertilization at a mean shell length of 168.0, 195.0, and 202.0 pm for T. crocea, T. maxima, and H. hippopus, respectively. Metamorphosis was basically complete about 1 day after settlement. Juveniles of T. crocea, T. maxima, and H. hippopus first acquire zooxanthellae after 19, 21, and 25 days, respectively. Growth rates increase sharply after the acquisition of zoo xanthellae. Juvenile shells show first signs of becoming opaque after 47 days for T. maxima and after 50 days for H. hippopus.

Abstracts of Papers: Albert L. Tester Memorial Symposium, 22-23 April 1976

Thu, 01 Jul 1976 00:00:00 GMT

In Memoriam: Albert Lewis Tester, 1908-1974

Thu, 01 Jul 1976 00:00:00 GMT

30:3 Table of Contents - Pacific Science

Thu, 01 Jul 1976 00:00:00 GMT

The Correlation of Soil Algae, Airborne Algae, and Fern Spores with Meteorological Conditions on the Island of Hawaii

Carson, Johnny L; Brown, R Malcolm Jr — Thu, 01 Apr 1976 00:00:00 GMT

Correlations of the generic diversity of soil and airborne algae with altitude on the island of Hawaii are noted. Distribution of the soil algae was determine d by culturing an aqueous soil extract from designated altitudes on agarized inorganic growth media. Distribution of airborne algae and fern spores was determined by investigations of viable particulate impactions on the surface of agarized inorganic growth media identical to that used in culturing the soil samples. Little correlation occurs between the generic diversity of the airborne and soil algae at corresponding altitudes, which suggests a cosmopolitan mixing of airborne propagules that have been released from different altitudes. However, striking relationships were noted in the quantitative determinations of airborne green and blue-green algae and of fern spore impactions with the varying meteorological conditions of rain, fog-mist, and clear, sunny conditions accompanying the altitude change.

Observations on the Morphology and Taxonomy of Phycopeltis hawaiiensis King (Chroolepidaceae)

Chapman, R L; Good, B H — Thu, 01 Apr 1976 00:00:00 GMT

Observations with light and scanning electron microscopes indicate the foliicolous chlorophyte Phycopeltis hawaiiensis King (Chroolepid aceae) is subcuticular and polystromatic, produces sterile hairs, and induces a distinct wounding, reaction in sub tending host tissue. In comparison, similar observations on Pbycopeltis epiphyton and other Phycopeltis species reveal that, although they are also foliicolous, they are supracuticular and monostromatic. Also, they neither produce sterile hairs nor induce a wounding response in the host leaf. Because the observed characteristics of Phycopeltis hawaiiensis are similar to those of Cepbaleuros virescens and other Cephaleuros species, it is suggested that Phycopeltis hawaiiensis is probably a Cepbaleuros species; however, the absence of reproductive structures renders the designation of a specific epithet problematic.

Reproduction of Acacia koa after Fire

Scowcroft, Paul G; Wood, Hulton B — Thu, 01 Apr 1976 00:00:00 GMT

The abundance, distribution, growth, and mortality of koa (Acacia koa Gray) seedlings after fires were monitored periodically on two burned areas on Oahu for 2.5 years. On one area, seedling density peaked at 95,300/ha 6 months after the fire; 21 months later it had declined to 18,500/ha. On the other area, peak seedling density occurred at 2 months, with 20,400/ha; 26 months later, density had dropped to 7900/ha. Seedlings were not distributed uniformly over the burned areas but were concentrated near koa seed trees. Height growth for seedlings on one area averaged 2.6 cm/mo; on the other, 1.9 cm/mo. Several pathogens were identified, but only the root-crown fungus, Calonectria crotalariae, caused serious damage. More than 50 percent of the mortality on one burn was attributed to it. The regeneration in the burned areas studied indicates that koa will continue to be a component of the forest vegetation.

Present Knowledge of the Systematics and Zoogeography of the Order Gorgonacea in Hawaii

Grigg, Richard W; Bayer, Frederick M — Thu, 01 Apr 1976 00:00:00 GMT

Past knowledge of the order Gorgonacea in Hawaii is based almost exclusively on the collections of the United States Fish Commission steamer Albatross in 1902, which contain 52 species. Recent efforts to investigate the ecology of precious coral have produced a new collection based on 183 dredge hauls and 10 dives with a submersible. This program is collectively referred to as the Sango Expedition. Of 59 species of gorgonians obtained by the Sango Expedition, 13 are considered to be new species and 28 new geographic records, bringing the total number of species considered to be present in Hawaii to 93 species. In contrast to the high diversity of gorgonians in the West Indies and the Indo-West-Pacific, the faunal list in Hawaii must still be considered depauperate. This is especially true in shallow water <75 m), where only one species is known. Although climatic deterioration during the Pleistocene could account for the scarcity of gorgonians in shallow water at the present time, this factor is unlikely to have affected deeper species. Furthermore, one would expect to find a modern complement of an ancestral faun a in shallow water if it had existed, as is true in the case of reef corals. The paucity of gorgonians in Hawaii may be due to isolation, which appears to have been a particularly effective barrier in shallow water. It is suggested that the only accessible route to Hawaii for gorgonians has been in deep water where, in the past, there were numerous stepping stones that may have aided dispersal. Moreover, chemical and physical gradients in deep water are relatively low. Why more deepwater species have not migrated into shallow water in Hawaii may be a reflection of their stenotypic character.

Thermal Tolerance in Tropical Versus Subtropical Pacific Reef Corals

Coles, Stephen L; Jokiel, Paul L; Lewis, Clark R — Thu, 01 Apr 1976 00:00:00 GMT

Upper lethal temperature tolerances of reef corals in Hawaii and at Enewetak, Marshall Islands, were determined in the field and under controlled laboratory conditions. Enewetak corals survived in situ temperatures of nearly 34° C, whereas 32° C was lethal to Hawaiian corals for similar short-term exposures. Laboratory determinations indicate that the upper thermal limits of Hawaiian corals are approximately 2° C less than congeners from the tropical Pacific. Differences in coral thermal tolerances correspond to differences in the ambient temperature patterns between geographic areas.

Observations on the Behavior and Shell Types of Cypraea moneta (Mollusca, Gastropoda) at Enewetak, Marshall Islands

Renaud, Maurice L — Thu, 01 Apr 1976 00:00:00 GMT

Aspects of the ecology and behavior of knobby and smooth Cypraea moneta at Enewetak Atoll, Marshall Islands, are presented. The habitats of C. moneta are described. A series of experiments based on aggregation, feeding, and male-female pairing indicated similarities and differences between the smooth and knobby forms. Smooth morphs follow mucous trails only of other smooth-shelled forms of C. moneta, whereas knobby morphs follow the mucous trails of both knobby and smooth forms. The most preferred alga of the smooth morphs is Jania capillacea, the most abundant species in intertidal areas; and that of the knobby morphs is Schizothrix calcicola, a common subtidal species. Male-female pairs constituted 80 percent of the intertidal samples and 81 percent of the subtidal ones. In addition, smooth and knobby morph distributions were investigated in the Line Islands and elsewhere in Micronesia as well as at Enewetak. In all cases the smooth morph was found in the intertidal zone and the knobby morph in the subtidal.

Sex Ratio, Size at Reproductive Maturity, and Reproduction of the Hawaiian Kona Crab, Ranina ranina (Linnaeus) (Brachyura, Gymnopleura, Raninidae)

Fielding, Ann; Haley, Samuel R — Thu, 01 Apr 1976 00:00:00 GMT

Sex ratio and size at reproduction of Ranina ranina (Linnaeus) in Hawaii were investigated. A sample of 1596 Kona crabs collected over 1 year in Hawaiian waters was examined to determine sex ratio and size at reproduction. Males constituted 55 percent of the overall samples and a similar proportion in all size classes. Males attain a larger maximum size than do females and have mature spermatozoa when their carapace length exceeds 60 mm. Secondary sexual characteristics in the male develop at a carapace length of about 75 mm. Females are ovigerous from May to September. Most ovarian growth occurs between February and May. In May, at the beginning of the spawning season, the number of eggs ovulated is a function of maternal body size: a 25-percent increase in carapace length is associated with a 200-percent increase in number of eggs ovulated. This is not so later in the spawning season (August-September). Larger females appear to ovulate at least twice each season, with the primary effort going into the first ovulation. The smallest 5-mm size class in which at least 50 percent of the females are ovigerous during the spawning season is 70.0-74.9 mm in carapace length. The mean minimum size of ovigerous females is 86 ± 8 mm in this dimension. The spermatheca in females is open to the outside at carapace lengths exceeding 60 mm. Eighteen crabs with carapace lengths less than 65 mm were captured. Half (31.9 mm-42.6 mm) were white in color and were all immature; the remaining half (43.6 mm-61.1 mm) were the usual orange color and all of these exhibited active gametogenesis. This correlation of color with size may be of significance for reproductive behavior.

Distribution, Morphometry, and Seasonal Biology of the Planktonic Copepods Neocalanus robustior and Neocalanus gracilis in the Pacific Ocean

Mullin, Michael M; Evans, Pamela M — Thu, 01 Apr 1976 00:00:00 GMT

A New Species of Plesionika (Crustacea, Decapoda, Pandalidae) from the Pacific Coast of Colombia

Squires, H J; Barragan, J H — Thu, 01 Apr 1976 00:00:00 GMT

Keloid in the Gray Reef Shark, Carcharhinus amblyrhynchos

Smith, Albert C; Hartley, Fount K — Thu, 01 Apr 1976 00:00:00 GMT

A gray reef shark, Carcharhinus amblyrhynchos, was captured at Enewetak Atoll, the Marshall Islands, in 1972. Near the right pectoral fin was a large fungating tumor. Microscopically, no evidence of microorganisms or definite malignant transformation was observed, and inflammation and necrosis were minimal. However, the tumor appeared to be a keloid, the first to be reported in sharks.

The Distribution of Total and Organic Mercury in Seven Tissues of the Pacific Blue Marlin, Makaira nigricans

Shultz, Cynthia D; Crear, David — Thu, 01 Apr 1976 00:00:00 GMT

Tissue samples from Pacific blue marlin (Makaira nigricans) were collected at a fishing tournament in Kona, Hawaii, in August 1973. Analyses of total and organic (methyl) mercury indicated that the marlin may be biotransforming methyl mercury to inorganic mercury such that about 90 percent of the body burden of mercury is in the inorganic form. Specific analysis of a subsample of the tissues showed that the difference between the total and organic mercury concentrations was equal to inorganic mercury by weight.

30:2 Table of Contents - Pacific Science

Thu, 01 Apr 1976 00:00:00 GMT

The Hydrogeology and Water Supply Problems in North-Central Chile

Lloyd, John W — Thu, 01 Jan 1976 00:00:00 GMT

The north-central zone of Chile is described with respect to groundwater supply problems. In this region, groundwater is almost exclusively obtained from the thin alluvium in the main transverse valleys, which descend from the Andes in those sections where the valleys cross the northerly trending "central valley." Because of the steep groundwater gradients prevailing, the groundwater resources are closely related to seasonal recharge. As the area is arid to semiarid and has been showing indications of increasing aridity over the past few years, water supply problems are proving to be a serious development constraint. Throughout the area, many examples of insufficient water supply may be encountered, and the problems of water use management and the utilization for industrial purposes of supplies such as seawater, brines, and sewage are now being considered.