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  • 1
    Electronic Resource
    Electronic Resource
    Behavioral aspects of sperm competition in cuttlefish, Sepia officinalis (Sepioidea: Cephalopoda) (1999)
    Springer
    Marine biology 134 (1999), S. 719-728 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Sexual selection studies in cephalopods indicate that sperm competition is a central feature of their mating systems, yet this has not been studied experimentally in any detail. In 1998 we staged 20 matings of the cuttlefish, Sepia officinalis L., in the laboratory. Males rapidly initiated mating in the “head-to-head” position, with no apparent courtship. Mating lasted an average of 10 min (range 7 to 14 min). For the first 6 min (on average 63% of the mating duration), the male flushed strong jets of water directly at the female's buccal membrane, which sometimes resulted in the expulsion of parts of spermatangia placed there in recent matings. Then, in a single discrete movement that lasted an average of only 14 s, the male's modified fourth left arm – the hectocotylus – wrapped around a single large bundle of spermatophores (ca. 150 to 300) and transferred them to the female's buccal membrane. For the remainder of the mating (average 3 min, range 1.5 to 5.0 min), the hectocotylus repeatedly broke the spermatophores open, and manipulated them, so that sperm were released and many spermatangia were attached along the ventral buccal membrane, near the paired seminal receptacles. Approximately 140 spermatangia were attached in rows 3 to 5 deep around the ventral buccal membrane in a single mating; the rest were usually discarded during mating. Histology revealed that each of the seminal receptacles consists of a series of sperm storage bulbs connected by a central duct, which leads to a single pore at the surface of the buccal membrane. Baseline data on sperm motility were obtained, but the mechanism by which sperm enter the seminal receptacle remains unknown. Females seemed to initiate termination of mating, then males guarded their mates temporarily. These results, combined with other recent laboratory experiments, provide evidence that sperm competition may be a major feature of the mating system of S. officinalis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050588
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  • 2
    Electronic Resource
    Electronic Resource
    Octopus bimaculoides (Pickford & McConnaughey, 1949): a marine invertebrate host for ectoparasitic protozoans (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish diseases 14 (1991), S. 0 
    Details
    ISSN: 1365-2761
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Abstract. During the laboratory culture of the California mud-fiat oetopus. Octopus bimaculoides(Pickford & McConnaughey, 1949), concurrent infestations of ectoparasitic flagellate and ciliate protozoans were discovered when examining sick and dying animals. The flagellates, similar to the bodonid parasite, Ichthyobodo necator (Henneguy, 1883), were small (3–9 μm total length) and infested any surface epithelia exposed to sea water. The larger ciliates (l5–30 μm total length), believed to be ancistrocomids, were found only on the gills. This is the first documented report of ciliate or flagellate ecto-parasites infesting cephalopod molluscs. Flagellate infestations were first manifest on the dorsal arms and mantle surfaces of O. bimaculoides as white spots visible when the octopuses were in dark colouration. Lesions formed at the centres of the spots and the interspersed lesions eventually connected. Once the parasites damaged the epidermis, secondary bacterial infections caused lesioning. Both parasites heavily infested the gills. Clinical signs first appeared at 2 months post-hatching (0-5 g). Octopuses seemed to become refractory to the disease beyond a size of 25 g. No effective treatment was found for these infestations. It was possible to eliminate parasite spread in the laboratory by prefiltering water to l μm. The source of the parasites was the wild octopus population of the southern California coast.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2761.1991.tb00595.x
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  • 3
    Electronic Resource
    Electronic Resource
    Scale and Corrosion Control in Potable Water Suplies at Army Posts. (1945)
    s.l. : American Chemical Society
    Industrial & engineering chemistry 37 (1945), S. 724-735 
    Details
    ISSN: 1520-5045
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ie50428a018
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  • 4
    Electronic Resource
    Electronic Resource
    Growth of the Eastern Atlantic squid, Loligo forbesi Steenstrup (Mollusca: Cephalopoda) (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 20 (1989), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. Loligo forbesi Steenstrup is a commercially and biomedically important species raneing from Scotland to North Africa and from the Azores Islands in the central Atlantic east through the Mediterranean Sea and Red Sea. Eggs were collected from Plymouth. England and from the Azores and the hatchlings were reared to adult size in recirculating seawater systems. Growth data were obtained primarily from mortalities during the course of three culture experiments which lasted 360, 240 and 480 days. Loligo forbesi hatched at a size of 5–9mg (3.0–4.6mm mantle length, ML) and grew to a maximum size of 124g (155 mm ML) in 413 days. In all experiments, growth was exponential in form for at least the first 3 months at rales of 5.8, 5.1 and 3.6% body weight per day (BW/d) at mean temperatures of 14.1, 14.0 and 13.1°C respectively. In one short-term experiment, month-old squids grew at 8.0% BW/d at 17.4°C. Growth beyond 3 months was slower and either logarithmic (as described by the power function) or exponential in form. Growth rates gradually declined to 1–2% BW/d, Analyses of mantle length growth confirmed the wet weight results. There was no evidence of sexual dimorphism in the laboratory populations, which were of small size, and the length-weight (L-W) relationships were found to be similar to those of field populations. Growth rates during the exponential growth phase appeared very sensitive to temperature, with a 1°C difference changing growth rate by 2% BW/d and producing a three-fold difference in weight at 90 days post-hatching. These dramatic effects of temperature on adult size and lifespan in nature are discussed. It is hypothesized that the small size of mature laboratory-reared squids was due to low culture temperatures during the first 3 months.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.1989.tb00437.x
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  • 5
    Electronic Resource
    Electronic Resource
    Laboratory culture and estimated life span of the Eastern Atlantic squid, Loligo forbesi Steenstrup, 1856 (Mollusca: Cephalopoda) (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 20 (1989), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. First culture results are presented from four major experiments (lasting up to 478 days) on the commercially important squid species, Loligo forbesi Steenstrup, Details are provided on eggs, hatching, feeding, growth, survival, behaviour and sexual maturation. Best survival during the critical first 75 days was 15%. The hatchlings (up to 4.9mm mantle length, ML) are the largest among the genus Loligo, and the largest squid grown was a male 155mm ML and 124g. First schooling was observed only 40–50 days post-hatching. Spawning was not achieved although males reached maturity, females had maturing ova and mating was observed. The largest giant axon measured was 425μm in diameter (from a female 130mm ML), a size suitable for most biomedical applications. Laboratory data suggest a 2-year life cycle compared to fishery data which suggest a 1-year cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.1989.tb00438.x
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of temperature on laboratory growth, reproduction and life span of Octopus bimaculoides (1988)
    Springer
    Marine biology 98 (1988), S. 369-379 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Laboratory culture of 40 Octopus bimaculoides from April 1982 to August 1983 through the full life cycle at 18°C vs 23°C provided information on the growth, reproductive biology and life span of this California littoral octopus. At 18°C, the cephalopods grew from a hatchling size of 0.07 g to a mean of 619 g in 404 d; the largest individual was 872 g. Octopuses cultured at 23°C reached their highest mean weight of 597 g in 370 d; the largest individual grown at this temperature was 848 g after 404 d. Growth data revealed a two-phase growth pattern: a 5 mo exponential phase followed by a slower logarithmic (power function) phase until spawning. At 5 mo octopuses grown at 23°C were over three times larger than their 18°C siblings. However, beyond 6.5 mo, growth rates were no higher at 23°C than at 18°C. At 13.5 mo, the mean weight of the 18°C group surpassed that of the 23°C group. The slope of the length/weight (L/W) relationship was significantly different for the two temperature regimes, with the 23°C octopuses weighing 18% less than their 18°C siblings at a mantle length of 100 mm. Females weighed more than males at any given mantle length. Males grew slightly larger and matured before females. The L/W relationship indicated isometric body growth throughout the life cycle. Higher temperature accelerated all aspects of reproductive biology and shortened life span by as much as 20% (from approximately 16 to 13 mo). O. bimaculoides has one of the longest life cycles among species with large eggs and benthic hatchlings. Extrapolations to field growth are made, and the possible effects of temperature anomalies such as El Niño are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00391113
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  • 7
    Electronic Resource
    Electronic Resource
    The effects of collembola grazing on microbial activity in decomposing leaf litter (1979)
    Springer
    Oecologia 38 (1979), S. 93-99 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ground leaf litter was inoculated with the fungus Coriolus versicolor and incubated in respirometers for 6 days (“fresh” cultures) or 33 days (“senescent” cultures) before different number of Folsomia candida were added. Grazing by 5 animals stimulated O2 consumption in both series of cultures but 10, 15 or 20 animals inhibited microbial respiration. The stimulatory effect was less marked in the senescent cultures. Bacterial and fungal standing crops increased in “fresh” cultures during the course of the experiment but grazing by collembola increased bacterial and reduced fungal standing, crops in proportion to the grazing intensity. Microbial standing crops were not determined for senescent cultures. Microarthropod feeding activities can therefore exert a strong differential effect on fungal and bacterial populations which has not been previously recognised.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00347827
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  • 8
    Electronic Resource
    Electronic Resource
    The breakdown and decomposition of allochthonous and autochthonous plant litter in an oligotrophic lake (Llyn Frongoch) (1982)
    Springer
    Hydrobiologia 88 (1982), S. 281-288 
    Details
    ISSN: 1573-5117
    Keywords: decomposition ; plant litter ; oligotrophic lake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The breakdown and decomposition of two species of deciduous leaf litter, Fagus sylvatica L. and Salix viminalis L. and two species of aquatic macrophyte Isoetes lacustris L. and Potamogeton perfoliatus L. were examined in an oligotrophic lake. In all cases plant litter in coarse mesh litter bags lost significantly more material than the fine mesh after 1 years submergence in the lake. This however was considered to be the result of physical environmental factors and microbial activity rather than animal processing. The litter was ranked in order of fastest to slowest rates of decay as follows — Isoetes, Potamogeton, Salix and Fagus. Decomposition processes proceeded at a relatively slow rate as a result of low temperatures and low phosphate and mineral ion concentration. The results suggested that there was an accumulation of organic material in the lake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00008508
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  • 9
    Electronic Resource
    Electronic Resource
    Allochthonous plant litter as a source of organic material in an oligotrophic lake (Llyn Frongoch) (1981)
    Springer
    Hydrobiologia 80 (1981), S. 257-261 
    Details
    ISSN: 1573-5117
    Keywords: plant litter ; organic material ; production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The importance of airborne plant litterfall as a source of organic material was evaluated for a small oligotrophic lake. The airborne plant litter input was estimated to be 100 kg yr−1 (45 kg C. yr−1), which represents approximately 5% of the phytoplankton productivity. The quantity of plant litter entering the lake followed an exponential decline with distance from the shore.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00018365
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  • 10
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    Hyperspectral imaging of cuttlefish camouflage indicates good color match in the eyes of fish predators (2011)
    National Academy of Sciences
    Details
    Publication Date: 2011-05-16
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
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