Reproductive biology and early life history of the hermaphroditic feather star Dorometra sesokonis (Echinodermata: Crinoidea)

Reproduction and larval/post-larval development of the one of the smallest known comatulid Dorometra sesokonis were studied on the coral reefs of Sesoko-jima Island, Okinawa, Japan. Breeding individuals were found every month from May 2003 to April 2004 indicating continuous reproduction. Individuals possessed both mature ovaries and testes, and were therefore characterized as simultaneous hermaphrodites. This species was observed to be an external brooder in which the embryos developed on the surface of parental genital pinnules until the doliolaria larval stage, and subsequently released doliolariae settled on substrata within 4 days after hatching. Larvae then metamorphosed into the post-larval cystidean stage, which lasted for more than a month. The reproductive features of this species are unique among crinoids, and, together with juvenile morphological features observed in adults, can be interpreted as adaptations to their cryptic habitat, which is subject to frequent natural disturbances.     

Ant foraging behavior: ambient temperature influences prey selection

Summary When prey of two sizes (6 and 32 mg) were offered in a choice situation to foragers of the ant Formica schaufussi at different ambient temperatures, significantly more workers rejected the smaller prey at low temperatures, whereas at high temperatures workers accepted the less profitable smaller item. Foragers scavenge for arthropod prey over a temperature range of 15–40°C, and increasing temperature significantly increases a forager's oxygen consumption, an index of energy expenditure.     

Collaborative modelling‐based shelter planning analysis: a case study of the Nagata Elementary School Community in Kobe City,Japan

This study, based on a questionnaire survey and workshops, and with a focus on the impact of an earthquake on the Nagata Elementary School Community in Kobe City, Japan, develops a collaborative model to assess the allocation of residents to shelters. The current official allocation plan is compared with three alternative allocations developed within the framework of this model. The collaborative model identifies accessibility, amenity, capacity, connectivity, continuity, security, and stability as the basic, necessary criteria for shelter planning. The three alternative allocations are very similar to the local residents’ own choice of shelters, but they are quite different from the current official allocation plan, which is supposed to be followed but has achieved relatively low satisfaction among households. The proposed collaborative approach provides an effective tool to assess the officially determined allocation plan by taking into account the viewpoints of local residents, and the results are useful for enhancing community evacuation planning.     

Anthropogenic impacts on water quality of the lagoonal coast of Fongafale Islet, Funafuti Atoll, Tuvalu

Water pollution, evident by negative values of redox potential in waters, occurs at the lagoonal coast located near the densely populated area of Fongafale Islet on Funafuti Atoll, Tuvalu, Central Pacific. Sediment microbial quinone analysis revealed that these coastal sediments exhibit 2.7–10.4 times more microbial biomass, significantly different microbial community structure and low microbial diversity, when compared to an undisturbed natural coastal sediment. Thus, the pollution is chronic. By considering the total land use/coverage on the islet, the situation of septic tank installations, temporal changes in water redox potential and Escherichia coli numbers in the coastal waters and the spatial distribution of acid volatile sulfide in the sediments, we conclude that domestic wastewater is the primary source of pollution. This pollution is proposed to occur via the following mechanism: during ebb tides, domestic wastewater leaking from bottomless septic tanks and pit toilets run off into the lagoonal coast. Tide changes control the pollution load of domestic wastewater.     

Accumulation and excretion of chloroanilines by carp

Accumulation and excretion of chloroanilines were studied for carp ( L.). The average bioconcentration factors (BCF) in the whole body of the fish after 24 – 336 hr exposure were 2.0 and 3.7 for o-chloroaniline. 0.8 and 2.2 for m-chloroaniline and 0.8 and 1.7 for p-chloroaniline at high and low concentrations of the chemicals, respectively. The excretion rate constants (k) from the whole body of the fish were 0.19 hr⁻¹ for o-chloroaniline, 0.21 hr⁻¹ for m-chloroaniline and 0.16 hr⁻¹ for p-chloroaniline. The experimental data on the accumulation and excretion of the chloroanilines were consistent with the field data.