79 research outputs found
Re-description of Chinese mitten crab Eriocheir sinensis H. Milne Edwards, 1853 (Crustacea: Brachyura: Grapsoidea: Varunidae) zoeal development using confocal laser scanning microscopy
No full textKamanli, Seyit A., Morritt, David, Ball, Alexander D., Goral, Tomasz, Clark, Paul F. (2018): Re-description of Chinese mitten crab Eriocheir sinensis H. Milne Edwards, 1853 (Crustacea: Brachyura: Grapsoidea: Varunidae) zoeal development using confocal laser scanning microscopy. Zootaxa 4507 (1): 1-67, DOI: https://doi.org/10.11646/zootaxa.4507.1.
FIGURE 53 in Re-description of Chinese mitten crab Eriocheir sinensis H. Milne Edwards, 1853 (Crustacea: Brachyura: Grapsoidea: Varunidae) zoeal development using confocal laser scanning microscopy
No full textFIGURE 53. An example measurement of dorsal, lateral and rostral spines using a ZI stage of Cancer magister (adapted from Shirley et al. 1987).Published as part of Kamanli, Seyit A., Morritt, David, Ball, Alexander D., Goral, Tomasz & Clark, Paul F., 2018, Re-description of Chinese mitten crab Eriocheir sinensis H. Milne Edwards, 1853 (Crustacea: Brachyura: Grapsoidea: Varunidae) zoeal development using confocal laser scanning microscopy, pp. 1-67 in Zootaxa 4507 (1) on page 65, DOI: 10.11646/zootaxa.4507.1.1, http://zenodo.org/record/371378
Data from: Year-round sexual harassment as a behavioral mediator of vertebrate population dynamics
No full textWithin-species sexual segregation is a widespread phenomenon among vertebrates but its causes remain a topic of much debate. Female avoidance of male coercive mating attempts has the potential to influence the social structure of animal populations, yet it has been largely overlooked as a driver of sexual separation. Indeed, its potential role in long-term structuring of natural populations has not been studied. Here we use a comparative approach to examine the suitability of multiple hypotheses forwarded to account for sexual segregation (i.e. activity budget; predation risk; thermal niche - fecundity; and social factors) as drivers underlying sex-specific habitat use in a monomorphic model vertebrate, the small spotted catshark, Scyliorhinus canicula. Using this hypothesis-driven approach we show that year-round sexual habitat segregation in S. canicula can be accounted for directly by female avoidance of male sexual harassment. Long-term electronic tracking reveals sperm-storing female catsharks form daytime refuging aggregations in shallow water caves (~3.2 m water depth), and undertake nocturnal foraging excursions into deeper water (~25 m) most nights. In contrast, males occupy deeper, cooler habitat (~18 m) by day, and exploit a range of depths nocturnally (1 - 23 m). Males frequent the locations of shallow water female refuges, apparently intercepting females for mating when they emerge from, and return to, refuges on foraging excursions. Females partly compensate for higher metabolic costs incurred when refuging in warmer habitat by remaining inactive; however, egg production rates decline in the warmest months, but despite this, refuging behavior is not abandoned. Thermal choice experiments confirm individual females are willing to 'pay' in energy terms to avoid aggressive males and unsolicited male mating attempts. Long-term evasion of sexual harassment influences both the social structure and fecundity of the study population with females trading-off potential injury and unsolicited matings with longer term fitness. This identifies sexual harassment as a persistent cost to females that can mediate vertebrate population dynamics.,11-2052 dataMS Excel spreadsheet containing data obtained under natural (field) and controlled (laboratory) conditions. Individual S. canicula were electronically tracked in the natural environment, whilst in the laboratory the movements of individuals were tracked using video tracking techniques. Observations made under both natural and controlled conditions are also included. See manuscript materials and methods for further details.</span
Year-round sexual harassment as a behavioral mediator of vertebrate population dynamics
No full textWithin-species sexual segregation is a widespread phenomenon among vertebrates but its causes remain a topic of much debate. Female avoidance of male coercive mating attempts has the potential to influence the social structure of animal populations, yet it has been largely overlooked as a driver of sexual separation. Indeed, its potential role in long-term structuring of natural populations has not been studied. Here we use a comparative approach to examine the suitability of multiple hypotheses forwarded to account for sexual segregation (i.e. activity budget; predation risk; thermal niche - fecundity; and social factors) as drivers underlying sex-specific habitat use in a monomorphic model vertebrate, the small spotted catshark, Scyliorhinus canicula. Using this hypothesis-driven approach we show that year-round sexual habitat segregation in S. canicula can be accounted for directly by female avoidance of male sexual harassment. Long-term electronic tracking reveals sperm-storing female catsharks form daytime refuging aggregations in shallow water caves (~3.2 m water depth), and undertake nocturnal foraging excursions into deeper water (~25 m) most nights. In contrast, males occupy deeper, cooler habitat (~18 m) by day, and exploit a range of depths nocturnally (1 - 23 m). Males frequent the locations of shallow water female refuges, apparently intercepting females for mating when they emerge from, and return to, refuges on foraging excursions. Females partly compensate for higher metabolic costs incurred when refuging in warmer habitat by remaining inactive; however, egg production rates decline in the warmest months, but despite this, refuging behavior is not abandoned. Thermal choice experiments confirm individual females are willing to 'pay' in energy terms to avoid aggressive males and unsolicited male mating attempts. Long-term evasion of sexual harassment influences both the social structure and fecundity of the study population with females trading-off potential injury and unsolicited matings with longer term fitness. This identifies sexual harassment as a persistent cost to females that can mediate vertebrate population dynamics
Synthetic and semi-synthetic fibre ingestion by mesopelagic fishes from Tristan da Cuhna and St Helena, South Atlantic
No full textAs part of the Blue Belt Programme, a marine survey of British Overseas Territories funded by the UK Government, RRS Discovery trawled at depths of between the surface and 1000m around Tristan da Cuhna and St Helena. Fishes were examined for microplastic ingestion.
This work was supported by the National Environmental Research Council [grant number NE/L002485/1] with co-sponsorship from a Fishmongers' Company Fisheries Charity Trust CASE Partnership. Specimens were collected onboard RRS Discover as part of the Blue Belt Programme, which is funded by the UK Government in collaboration with CEFAS and BAS.
Mesopelagic fishes were sampled around Tristan da Cunha and St Helena in the South Atlantic from the RRS Discovery at depths down to 1000 m. Sampling was part of the Blue Belt Programme, a marine survey of British Overseas Territories funded by the United Kingdom Government. Thirteen species of mesopelagic fishes identified from 30 specimens were compared with two species (two specimens) collected from rock pools or surface water near the shore. The digestive tracts of all fishes were examined for microplastics. Additionally, one specimen of Opostomias micripnus (Günther, 1878) was analyzed after recovery from the stomach of a commercially fished species, Hyperoglyphe antarctica (Carmichael, 1819). One specimen of Anoplogaster cornuta was found to have ingested a bearded sea devil (Linophryne sp.), a cock-eyed squid (Histioteuthis sp.), a bolitaenid octopus, Japetella diaphana, remains of unidentifiable fish, crustaceans, and possibly salps. These prey items were also examined for microfibres. Both Histioteuthis sp. and Linophryne sp. had ingested fibers and these were considered “ingested particles” for A. cornuta. Neither shallow water dwelling species had ingested microplastics, whilst 11 of the 13 studied mesopelagic species were found to be contaminated. Overall, 66.7% of mesopelagic fishes were found to contain microfibres. Anthropogenic fibers were common especially viscose, a semi-synthetic material which is associated with sanitary products as well as other items.Copyright © 2021 McGoran, Maclaine, Clark and Morritt. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.NHM Repositor
Some observations upon the Vindication of Homer, and of the ancient poets and historians, who have recorded the siege and fall of Troy, written by I.B.S. Morritt, esq. /
No full textFinal leaf blank, with errata slip attached.Signatures: A² B-N⁴ [M]1.ESTC(RLIN)Mode of access: Internet.Library copy bound with: Description of the plain of Troy : with a map of that region, delineated from an actual survey : read in French before the Royal Society of Edinburgh, Feb. 21 and 28 and March 21 1791 / by the author, M. Chevalier. Edinburgh : Printed for T. Cadell, 1791. (90-B15413
The crab carrion-scavenging amphipod, <i>Orchomene nanus</i> in Lough Hyne, Co. Cork, Ireland
No full textAmphipod traps baited with crab carrion caught significantly greater numbers of the specialist crab necrophage, Orchomene nanus in the South Basin of Lough Hyne than in the North Basin. The results can be explained with reference to the known distribution of crab species in the lough and also the hydrographical characteristics of the two basins.</jats:p
Upper thermal tolerances of the beachflea Orchestia gammarellus (Pallas) (Crustacea: Amphipoda: Talitridae) associated with hot springs in Iceland
No full textScaling laws of marine predator search behaviour
No full textMany free-ranging predators have to make foraging decisions with little, if any, knowledge of present resource distribution and availability. The optimal search strategy they should use to maximize encounter rates with prey in heterogeneous natural environments remains a largely unresolved issue in ecology. Lévy walks are specialized random walks giving rise to fractal movement trajectories that may represent an optimal solution for searching complex landscapes. However, the adaptive significance of this putative strategy in response to natural prey distributions remains untested. Here we analyse over a million movement displacements recorded from animal-attached electronic tags to show that diverse marine predators-sharks, bony fishes, sea turtles and penguins-exhibit Lévy-walk-like behaviour close to a theoretical optimum. Prey density distributions also display Lévy-like fractal patterns, suggesting response movements by predators to prey distributions. Simulations show that predators have higher encounter rates when adopting Lévy-type foraging in natural-like prey fields compared with purely random landscapes. This is consistent with the hypothesis that observed search patterns are adapted to observed statistical patterns of the landscape. This may explain why Lévy-like behaviour seems to be widespread among diverse organisms, from microbes to humans, as a 'rule' that evolved in response to patchy resource distributions.David W. Sims, Emily J. Southall, Nicolas E. Humphries, Graeme C. Hays, Corey J. A. Bradshaw, Jonathan W. Pitchford, Alex James, Mohammed Z. Ahmed, Andrew S. Brierley, Mark A. Hindell, David Morritt, Michael K. Musyl, David Righton, Emily L. C. Shepard, Victoria J. Wearmouth, Rory P. Wilson, Matthew J. Witt & Julian D. Metcalf
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