Effect of Activity on Energy Allocation in the Northern Abalone, Haliotis Kamtschatkana (Jonas)

The effect of activity, in the form of increased respiratory energy expenditure and secretion of mucus, on the summer and winter energy budgets of Haliotis kamtschatkana was assessed. Abalone exhibited seasonal variations in field activity with 20% of all individuals observed crawling during June to October, compared with -1 quiescent 12.0 h day-1 alert. O.7 h day-1 feeding, and 1.5 h day-1 crawling during the summer, and 15.8 h day-1 quiescent, 5.5 h day-1 alert, 2.3 h day-1 feeding, and o.4 h day-1 crawling during the winter. Videotapes of abalone made over 24-h periods revealed that abalone usually crawl at a rate of one shell length min-1. Locomotion is not continuous; rather, abalone stop and then start again, on average twice per meter. Components of the energy budget, C = F + U + Pg + Pr + R + M were measured during summer and winter months. None of the slopes of regression of log10energy (J day-1) on log10mass (g) was significantly different between summer and winter for any of the energy budget components, except those of somatic growth on mass. Summer y-intercepts were all significantly higher than winter y-intercepts, indicating that energy consumption and expenditure were higher during the summer. Respiratory energy expenditure was the largest component of both summer and winter budgets. Activity accounted for 23% of total consumed energy during the summer and 13% during the winter

Seasonality in Digestive-Gland Size and Metabolism in Relation to Reproduction in Haliotis kamtschatkana

A novel method of isolating digestive gland cells in abalone was used to provide information on the metabolic activity of this gland in Haliotis kamtschatkana. Activity, expressed as percent ·change in Vo2 of isolated cells before and after the addi­tion of glucose and amino acid substrates, was studied in relation to sex and to seasonal changes in gonad and digestive gland indices. At 3- to 4-mo intervals between May 1995 and July 1996, five collections of 10 adult abalone (equal sexes) were made from the West Coast of Vancouver Island, British Columbia. Each animal\u27s live mass (without shell) was recorded, and its gonad was aspirated from the digestive gland into a known volume (and mass) of seawater. The digestive gland was sliced free of its attachment, weighed, and related to shell-less body mass as percent digestive gland index (DGI). The gonad live mass was determined from the mass of aspirated mix of gonad and seawater, and related to shell-less body mass to give a percent gonad index (GI). Digestive gland cells were prepared and maintained in a special buffer, and their Vo2 \u27s measured in microrespirometers. There was no sex effect on seasonal DGI, but significant seasonal differences in DGls correlated perfectly with metabolic activity of digestive-gland cells with glucose substrate. Thus, when digestive glands were largest relative to body size, metabolic activity of their cells was greatest. Gls were significantly higher for males than females. There was a significant seasonal effect on Gls, with values being high in springtime be­ fore spawning (April to May, 10-11%) and low in winter (December, 6%), but with statistical overlap between these and sum­mer values (July to August, 7-8%). Metabolic response of the digestive gland cells was highest with glucose substrate (75% increase over presubstrate resting levels as compared with 4% for amino acid substrate), reflecting the carbohydrate-based metabolism of abalone

Functional Significance of Varicies in the Muricid Gastropod Ceratostoma foliatum

Functional significance of varices in the mur­icid gastropod Ceratostoma foliatum was investigated from the standpoints of (1) frequency of landing in the two upside-down orientations after short vertical falls of less than five body lengths through seawater and energy costs of righting from these upside-down positions, and (2) scaling relationships of varix areas with other body dimensions. Field manipulations showed that C.foliatum occupied habitats that mostly permit short falls of less than five body lengths upon dislodgment, as might occur during predation by fish. After short vertical falls in the laboratory, animals landed 48% of the time on their ap­erture sides (upright), 15% on their right sides (on right and middle varices), and 37% on their left sides (on left and middle varices). These frequencies differed signifi­cantly from the expected frequencies calculated on the basis of the percentage circumference delineated by each varix pair (50%, 31%, and 19%, respectively). Righting from the right-side orientation was slower and four times more energetically costly than from the left-side orientation, underscoring the advantage conferred by animals, ifnot landing in the upright position after short falls, pref­erentially landing on their left sides. Removal of individual varices showed that the large, right varix is most influential in producing this destabilization. Landings are biased to the side from which rightings are easiest due to a com­bination of the location of center of mass within the left side of the main body whorl and the broad right varix possibly acting as an upward-trailing vane. Morphometric relationships of shell length, live weight, varix areas, aperture dimensions, and labial spine (tooth) length were investigated over a wide range of body sizes in an attempt to infer varix function. Aperture area scaled allometrically with length. Right-, middle-, and left-varix areas also grew relatively larger as the animals increased in length. In contrast, combined varix areas around the aperture increased in direct proportion with aperture area, forming a broad shelf surrounding the aperture. We infer from this that, in addition to their effects on landing orientation from both long and short vertical falls, the varices of C. foliatum may function to protect the aperture, and thus protect the soft body parts that protrude from it dur­ing feeding and locomotion

Investigating the Uncanny Valley for prosthetic hands

Background: In 1970, Mori hypothesised the existence of an ‘uncanny valley’, whereby stimuli falling short of being fully human are found to be creepy or eerie. Objectives: To investigate how eerie people find different prosthetic hands and whether perceptions of eeriness can be accounted for by categorical ambiguity. Study Design: Students participated in computerised experiments during which photographic images of hands were presented. Methods: We compared photographs of prosthetic hands pre-selected as more (H+) or less human-like (H-), as well as mechanical and real hands. Participants rated the hands for eeriness and human-likeness, as well as performing a speeded classification (human/non-human) and location judgment (control) task. Results: The H- prosthetic hands were rated as more eerie than the H+ prosthetic, mechanical and real hands, and this was unaffected by hand orientation. Participants were significantly slower to categorise the H+ prosthetic hands compared to the H- prosthetic and real hands, which was not due to generally slower responses to the H+ prosthetic hands (control task). Conclusions: People find prosthetic hands to be eerie, most consistently for less human-like prosthetic hands. This effect is not driven by ambiguity about whether to categorise the prosthetic hand as human or artificial

Isolation and Chemical Composition of Dinoflagellate Nuclei *

Nuclei were isolated from Peridinium cinctum. Peridinium trochoideum, Gyrodinium cohnii ( Cryptothecodinium cohnii ) and Gymnodinium nelsoni. The nuclei of G. cohnii, P. trochoideum and G. nelsoni were found to contain ∼ 6.9, 34 and 143 picograms of DNA respectively. The ratios to DNA of RNA, acid-soluble and acid-insoluble protein for G. cohnii were 0.32, 0.13 and 0.99, respectively. The corresponding values for P. trochoideum were 0.22, 0.08 and 1.22, while those for G. nelsoni were 0.21, 0.10 and 1.09. The chemical composition of dinoflagellate nuclei is compared and contrasted with that of typical eukaryotic nuclei. The culture of these difficult organisms also is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72006/1/j.1550-7408.1973.tb03595.x.pd

Sea-land transitions in isopods: pattern of symbiont distribution in two species of intertidal isopods Ligia pallasii and Ligia occidentalis in the Eastern Pacific

Studies of microbial associations of intertidal isopods in the primitive genus Ligia (Oniscidea, Isopoda) can help our understanding of the formation of symbioses during sea-land transitions, as terrestrial Oniscidean isopods have previously been found to house symbionts in their hepatopancreas. Ligia pallasii and Ligia occidentalis co-occur in the high intertidal zone along the Eastern Pacific with a large zone of range overlap and both species showing patchy distributions. In 16S rRNA clone libraries mycoplasma-like bacteria (Firmicutes), related to symbionts described from terrestrial isopods, were the most common bacteria present in both host species. There was greater overall microbial diversity in Ligia pallasii compared with L. occidentalis. Populations of both Ligia species along an extensive area of the eastern Pacific coastline were screened for the presence of mycoplasma-like symbionts with symbiont-specific primers. Symbionts were present in all host populations from both species but not in all individuals. Phylogenetically, symbionts of intertidal isopods cluster together. Host habitat, in addition to host phylogeny appears to influence the phylogenetic relation of symbionts

Anti-photoaging and Photoprotective Compounds Derived from Marine Organisms

Marine organisms form a prominent component of the oceanic population, which significantly contribute in the production of cosmeceutical and pharmaceutical molecules with biologically efficient moieties. In addition to the molecules of various biological activities like anti-bacterial, anti-cancerous, anti-inflammatory and anti-oxidative etc., these organisms also produce potential photoprotective or anti-photoaging agents, which are attracting present day researchers. Continuous exposure to UV irradiation (both UV-A and UV-B) leads to the skin cancer and other photoaging complications, which are typically mediated by the reactive oxygen species (ROS), generated in the oxidative pathways. Many of the anti-oxidative and anti-photoaging compounds have been identified previously, which work efficiently against photodamage of the skin. Recently, marine originated photoprotective or anti-photoaging behavior was observed in the methanol extracts of Corallina pilulifera (CPM). These extracts were found to exert potent antioxidant activity and protective effect on UV-A-induced oxidative stress in human dermal fibroblast (HDF) cells by protecting DNA and also by inhibiting matrix metalloproteinases (MMPs), a key component in photoaging of the skin due to exposure to UV-A. The present review depicts various other photoprotective compounds from algae and other marine sources for further elaborative research and their probable use in cosmeceutical and pharmaceutical industries

Aspects of the breeding biology of Janaira gracilis Moreira & Pires (Crustacea, Isopoda, Asellota)

The biological aspects of incubating females of Janaira gracilis Mbreira & Pires, are described. The marsupium is formed by 4 pairs of oostegites arising from pereopods I-IV. The oostegites appear for the first time at the post-marsupial stage 7 (preparatory stage 1), growing successively at each moult until stage 9 (brooding stage 1), when they reach fully development. The sizes of the eggs increase with the body size of the females. The number of eggs, per female, is a linear function of the body volume, i.e., the fecundity increases with the female's body size. The number of eggs, embryos and juveniles decrease during the marsupial development. This decrease in brood number is higher between the last two marsupial stages, i.e., from stage C to D, than between the preceding marsupial stages. The average and overall brood mortality rate is of 38.95%.São descritos, no presente trabalho, vários aspectos relacionados à biologia de fêmeas grávidas de Janaira gracilis Moreira & Pires. O marsúpio é formado por 4 pares de oostégitos, que partem dos pereópodos I-IV. Os oostégitos, que surgem pela primeira vez no estádio 7 do desenvolvimento pós-marsupial (estágio preparatório 1), crescem nas sucessivas mudas, atingindo no estágio 9 (estágio reprodutor 1) seu pleno desenvolvimento. O tamanho dos ovos é proporcional ao tamanho das fêmeas. O número de ovos, por fêmeas, e proporcional ao volume das fêmeas, isto é, a fecundidade é mais elevada nos exemplares de maior comprimento. O número de ovos, embriões e jovens decresce com o desenvolvimento marsupial, sendo este decréscimo maior entre os dois últimos estágios marsupials (i.é., entre os estágios C e D) do que entre os estágios precedentes. A taxa média de mortalidade marsupial é de 38.95%

Phylogeography of Supralittoral Rocky Intertidal Ligia Isopods in the Pacific Region from Central California to Central Mexico

Ligia isopods are widely distributed in the Pacific rocky intertidal shores from central California to central Mexico, including the Gulf of California. Yet, their biological characteristics restrict them to complete their life cycles in a very narrow range of the rocky intertidal supralittoral. Herein, we examine phylogeographic patterns of Ligia isopods from 122 localities between central California and central Mexico. We expect to find high levels of allopatric diversity. In addition, we expect the phylogeographic patterns to show signatures of past vicariant events that occurred in this geologically dynamic region.We sequenced two mitochondrial genes (Cytochrome Oxidase I and 16S ribosomal DNA). We conducted Maximum Likelihood and Bayesian phylogenetic analyses. We found many divergent clades that, in general, group according to geography. Some of the most striking features of the Ligia phylogeographic pattern include: (1) deep mid-peninsular phylogeographic breaks on the Pacific and Gulf sides of Baja peninsula; (2) within the Gulf lineages, the northern peninsula is most closely related to the northern mainland, while the southern peninsula is most closely related to the central-southern mainland; and, (3) the southernmost portion of the peninsula (Cape Region) is most closely related to the southernmost portion of mainland.Our results shed light on the phylogenetic relationships of Ligia populations in the study area. This study probably represents the finest-scale phylogeographic examination for any organism to date in this region. Presence of highly divergent lineages suggests multiple Ligia species exist in this region. The phylogeographic patterns of Ligia in the Gulf of California and Baja peninsula are incongruent with a widely accepted vicariant scenario among phylogeographers, but consistent with aspects of alternative geological hypotheses and phylo- and biogeographic patterns of several other taxa. Our findings contribute to the ongoing debate regarding the geological origin of this important biogeographic region