scholarly journals Growth of the ass's ear abalone (Haliotis asinina Linné) on Heron Reef, tropical eastern Australia

1995 ◽  
Vol 46 (3) ◽  
pp. 571 ◽  
Author(s):  
DC McNamara ◽  
CR Johnson
Keyword(s):  
Growth Rate ◽  
Shell Length ◽  
Frequency Distributions ◽  
Haliotis Asinina ◽  
Length Relationship ◽  
Abalone Species ◽  
Eastern Australia ◽  
Field Peak ◽  
One Year

Growth of ass's ear abalone (Haliotis asinina) was measured in situ (mark-recapture of adults) and in aquaria (juveniles) on Heron Reef, Queensland. A growth curve (y = 4.27L2.03 e-u, where y is the growth rate, L is the shell length, and u = 0.27L0.88) fitted to these data indicated a sigmoidal age-length relationship. It is estimated that H. asinina may grow from 2 mm to 35.6 mm in shell length in six months and 55.0 mm in one year. These growth estimates are consistent with temporal shifts in the size-frequency distributions of juveniles in the field. Peak growth rates, estimated at over 120 mm year-1 in young abalone (approximately 3-4 months of age), are the highest recorded for any abalone species.

Small Scale Laboratory Culture of the Ormer, Haliotis Tuberculata

1982 ◽  
Vol 62 (4) ◽  
pp. 835-844 ◽  
Author(s):  
Ikuo Hayashi
Keyword(s):  
Growth Rate ◽  
Shell Length ◽  
Sea Water ◽  
Laboratory Culture ◽  
Small Scale ◽  
Haliotis Tuberculata ◽  
In The Wild ◽  
Gamete Production ◽  
One Year ◽  
Open Mesh

A simple aquarium system was used to keep large ormers collected from the wild and to rear juveniles from fertilization up to age one year. Spawning was induced by exposure to u.v. irradiated sea water and counts made of gamete production. Repeated spawning was observed in males and from egg counts it was inferred that females also undergo repeat spawning in the wild.Juvenile ormers were reared on simple collectors up to 4 mm shell length and later in open mesh cages. There was large variation in growth rate between individuals among the juvenile ormers. After one year shell lengths varied in the range 6·2–21·o mm.Twenty-three adult ormers (shell length 40·4–93·6 mm) were reared for eight months in a tank with a concrete shelter. The smaller ormers remained under the shelter much more than the larger ones, some of which adopted a permanent position outside the shelter. In the study period growth was greater in the smaller specimens (less than 70 mm shell length) than in the larger ones.

Small Scale Laboratory Culture of the Ormer, Haliotis Tuberculata

1982 ◽  
Vol 62 (4) ◽  
pp. 835-844
Author(s):  
Ikuo Hayashi
Keyword(s):  
Growth Rate ◽  
Shell Length ◽  
Sea Water ◽  
Laboratory Culture ◽  
Small Scale ◽  
Haliotis Tuberculata ◽  
In The Wild ◽  
Gamete Production ◽  
One Year ◽  
Open Mesh

A simple aquarium system was used to keep large ormers collected from the wild and to rear juveniles from fertilization up to age one year. Spawning was induced by exposure to u.v. irradiated sea water and counts made of gamete production. Repeated spawning was observed in males and from egg counts it was inferred that females also undergo repeat spawning in the wild.Juvenile ormers were reared on simple collectors up to 4 mm shell length and later in open mesh cages. There was large variation in growth rate between individuals among the juvenile ormers. After one year shell lengths varied in the range 6·2–21·o mm.Twenty-three adult ormers (shell length 40·4–93·6 mm) were reared for eight months in a tank with a concrete shelter. The smaller ormers remained under the shelter much more than the larger ones, some of which adopted a permanent position outside the shelter. In the study period growth was greater in the smaller specimens (less than 70 mm shell length) than in the larger ones.

Early development of eel-tailed catfish, Tandanus tandanus (Mitchell) (Teleostei : Plotosidae), with validation of daily otolith increment formation

2017 ◽  
Vol 65 (1) ◽  
pp. 12 ◽  
Author(s):  
K. R. Burndred ◽  
B. J. Cockayne ◽  
D. C. Lou
Keyword(s):  
Life History ◽  
Early Life ◽  
Early Life History ◽  
Population Declines ◽  
Length Relationship ◽  
Eastern Australia ◽  
Otolith Increment ◽  
Increment Formation ◽  
Nest Depth

Eel-tailed catfish, Tandanus tandanus, have recently experienced widespread population declines in eastern Australia; with some southern populations facing the risk of extinction, the management and conservation of Queensland populations should be considered a priority. There is a lack of sound, scientific knowledge surrounding the species’ reproductive patterns and early life-history requirements. To assist in clarifying the influence of changes to the natural environment on the reproductive ecology of T. tandanus, we investigated their early life history using naturally fertilised eggs and larvae from a wild population. Nest depth ranged from 0.20 m to 1.35 m, with in situ temperatures between 15.1°C and 29.9°C, and in situ velocities from 0.00 to 0.52 ms–1. Eggs ranged in diameter from 2.6 to 4.0 mm throughout development, and preservation of eggs in ethanol caused significant shrinkage (mean 18.9%). Hatching took 4–7 days (mean 5.29 days; 15.7–28.0°C). Larvae collected from nests ranged in length from 5.1 mm to 15.3 mm SL, and in age from one day old to 16 days old. Larvae are likely to actively disperse from their nest at ~16 days old, as they approach juvenile metamorphosis. Daily otolith increment formation was validated up to 28 days after hatching; and sagittal otoliths were used to develop an age–length relationship for larvae. These results can assist researchers in estimating the timing of critical recruitment events, and investigating how the species’ early life history is influenced by environmental conditions.

scholarly journals Effects of shoreline oiling on salt marsh epifaunal macroinvertebrates

2015 ◽  
Author(s):  
Donald R Deis ◽  
John W Fleeger ◽  
Stefan M Bourgoin ◽  
Irving A Mendelssohn ◽  
Qianxin Lin ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Shell Length ◽  
Salt Marshes ◽  
Fiddler Crab ◽  
Negative Effects ◽  
Frequency Distributions ◽  
Littoraria Irrorata ◽  
Biological Responses ◽  
Significant Difference ◽  
One Year

The Deepwater Horizon oil spill resulted in varying degrees of oiling in the salt marshes of northern Barataria Bay, Louisiana, USA. This study examines the effects of oiling intensity and recovery on two conspicuous marsh-platform macroinvertebrates, Uca spp., fiddler crabs, and Littoraria irrorata, the salt marsh periwinkle, from 2.5 to 4.5 years after the spill. The dominant fiddler crab within these marshes, Uca longisignalis, was the only species observed in field collections, and no significant difference in burrow density or burrow size was found among oiling levels over the study period indicating recovery from any negative effects of oiling already occurred for this species. The highest density of L. irrorata was found at moderately oiled sites compared to both reference (without visible oiling) and heavily oiled stations. Spartina alterniflora density recovered within two years after the spill at the moderately oiled stations facilitating recovery of L. irrorata approximately one year later. L. irrorata average shell length and length-frequency distributions were equivalent at moderately oiled and reference stations but snails were shorter at heavily oiled stations because of a greater proportion of subadults. Shell length data from the heavily oiled sites indicate that direct mortality due to oiling or oil-induced reductions in recruitment occurred in 2010 and that recovery was starting to occur at 48 months after the spill. The extent and duration of oil in the water during the spill and the biological responses we measured indicates that L. irrorata and Uca longisignalis were both affected in their ability to carry out their life cycle on the marsh and/or in the water column at all stations including the reference stations for some period following the entry of oil into the region.

scholarly journals In situ giant clam growth rate behavior in relation to temperature: A one-year coupled study of high-frequency noninvasive valvometry and sclerochronology

2011 ◽  
Vol 56 (5) ◽  
pp. 1940-1951 ◽  
Author(s):  
Caroline Schwartzmann ◽  
Gilles Durrieu ◽  
Mohamedou Sow ◽  
Pierre Ciret ◽  
Claire E. Lazareth ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Frequency ◽  
Giant Clam ◽  
Rate Behavior ◽  
One Year

scholarly journals Contributions to the knowledge of the Biology of the Arabian Abalone Haliotis mariae Wood, 1828

1996 ◽  
Vol 1 ◽  
pp. 33
Author(s):  
J. Stirn ◽  
K. A. AI-Hashmi
Keyword(s):  
Growth Rate ◽  
Fisheries Management ◽  
Larval Settlement ◽  
Larval Rearing ◽  
Artificial Reproduction ◽  
Laboratory Rearing ◽  
Abalone Species ◽  
Pelagic Eggs ◽  
Ecological Importance ◽  
One Year

The Arabian abalone occur in the Arabian Sea’s rocky coastal zone in association with conspicuous macrolgal communities in which it represents the dominant herbivorous component. Despite such ecological importance and although the commercial exploitation of abalone presents a considerable contribution to Omani fisheries, almost nothing is known about the biology of this species. This report presents results of research carried out in the field and with laboratory cultures, and draws general conclusions related also to the fisheries management of these possibly overexploited abalone populations, Cobort observations in the field and measured increments of cultured specimens showed a growth rate significantly higher than in other abalone species, i.e. greater than 3 mm shell-increment per month. The very early sexual maturity demonstrated by captivity spawnings of approximately one year old animals is also quite unusual. The ejected eggs formed mucous mono layers attached to the substratum whereas other abalone species produce pelagic eggs. Jvenile coborts in nature and the periodic spawning of cultured animals indicate the major spawning in spring and postmonsoon one in autumn. The models previously applied in fisheries management of abalone in Oman assumed only one spawning per year, the first being at age 2+, and a slower growth-rate. These models should be reconsidered using the new data, which may partially explain why abalone are less overexploited than one would expect looking at heavy harvesting. In view of a projected commercial abalone cultivation our laboratory rearing experiments showed that both natural and/or artificial food may be used, provided this contains-apart from standard ingredients, the seaweed-borne components (probably phycobillins) required for a normal parasite , resistant shell formation. With regard to artificial reproduction,  our preliminary trials showed that spawning , fertilization ,and initial larval rearing present no problems. The steps from the pediveliger to larval settlement, however ,seem to be fatally exposed to eilitate attacks. Further research is needed in order to eliminate this critical problem.

scholarly journals Effects of shoreline oiling on salt marsh epifaunal macroinvertebrates

2015 ◽  
Author(s):  
Donald R Deis ◽  
John W Fleeger ◽  
Stefan M Bourgoin ◽  
Irving A Mendelssohn ◽  
Qianxin Lin ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Shell Length ◽  
Salt Marshes ◽  
Fiddler Crab ◽  
Negative Effects ◽  
Frequency Distributions ◽  
Littoraria Irrorata ◽  
Biological Responses ◽  
Significant Difference ◽  
One Year

The Deepwater Horizon oil spill resulted in varying degrees of oiling in the salt marshes of northern Barataria Bay, Louisiana, USA. This study examines the effects of oiling intensity and recovery on two conspicuous marsh-platform macroinvertebrates, Uca spp., fiddler crabs, and Littoraria irrorata, the salt marsh periwinkle, from 2.5 to 4.5 years after the spill. The dominant fiddler crab within these marshes, Uca longisignalis, was the only species observed in field collections, and no significant difference in burrow density or burrow size was found among oiling levels over the study period indicating recovery from any negative effects of oiling already occurred for this species. The highest density of L. irrorata was found at moderately oiled sites compared to both reference (without visible oiling) and heavily oiled stations. Spartina alterniflora density recovered within two years after the spill at the moderately oiled stations facilitating recovery of L. irrorata approximately one year later. L. irrorata average shell length and length-frequency distributions were equivalent at moderately oiled and reference stations but snails were shorter at heavily oiled stations because of a greater proportion of subadults. Shell length data from the heavily oiled sites indicate that direct mortality due to oiling or oil-induced reductions in recruitment occurred in 2010 and that recovery was starting to occur at 48 months after the spill. The extent and duration of oil in the water during the spill and the biological responses we measured indicates that L. irrorata and Uca longisignalis were both affected in their ability to carry out their life cycle on the marsh and/or in the water column at all stations including the reference stations for some period following the entry of oil into the region.

The threshold energy for atom displacement in fcc metals

1990 ◽  
Vol 48 (4) ◽  
pp. 530-531
Author(s):  
Wilfried Sigle ◽  
Matthias Hohenstein ◽  
Alfred Seeger
Keyword(s):  
Growth Rate ◽  
Elevated Temperatures ◽  
Threshold Energy ◽  
Dislocation Loops ◽  
Absolute Minimum ◽  
Voltage Electron ◽  
Atom Displacement ◽  
Electron Microscopes ◽  
Fcc Metal

Prolonged electron irradiation of metals at elevated temperatures usually leads to the formation of large interstitial-type dislocation loops. The growth rate of the loops is proportional to the total cross-section for atom displacement,which is implicitly connected with the threshold energy for atom displacement, Ed . Thus, by measuring the growth rate as a function of the electron energy and the orientation of the specimen with respect to the electron beam, the anisotropy of Ed can be determined rather precisely. We have performed such experiments in situ in high-voltage electron microscopes on Ag and Au at 473K as a function of the orientation and on Au as a function of temperature at several fixed orientations.Whereas in Ag minima of Ed are found close to <100>,<110>, and <210> (13-18eV), (Fig.1) atom displacement in Au requires least energy along <100>(15-19eV) (Fig.2). Au is thus the first fcc metal in which the absolute minimum of the threshold energy has been established not to lie in or close to the <110> direction.

scholarly journals Linking population size structure, heat stress and bleaching responses in a subtropical endemic coral

Coral Reefs ◽  
2021 ◽  
Author(s):  
Liam Lachs ◽  
Brigitte Sommer ◽  
James Cant ◽  
Jessica M. Hodge ◽  
Hamish A. Malcolm ◽  
...  
Keyword(s):  
Heat Stress ◽  
Size Structure ◽  
Temporal Trends ◽  
Early Recovery ◽  
Size Frequency Distribution ◽  
Frequency Distributions ◽  
Community Organisation ◽  
Size Frequency ◽  
Eastern Australia

AbstractAnthropocene coral reefs are faced with increasingly severe marine heatwaves and mass coral bleaching mortality events. The ensuing demographic changes to coral assemblages can have long-term impacts on reef community organisation. Thus, understanding the dynamics of subtropical scleractinian coral populations is essential to predict their recovery or extinction post-disturbance. Here we present a 10-yr demographic assessment of a subtropical endemic coral, Pocillopora aliciae (Schmidt-Roach et al. in Zootaxa 3626:576–582, 2013) from the Solitary Islands Marine Park, eastern Australia, paired with long-term temperature records. These coral populations are regularly affected by storms, undergo seasonal thermal variability, and are increasingly impacted by severe marine heatwaves. We examined the demographic processes governing the persistence of these populations using inference from size-frequency distributions based on log-transformed planar area measurements of 7196 coral colonies. Specifically, the size-frequency distribution mean, coefficient of variation, skewness, kurtosis, and coral density were applied to describe population dynamics. Generalised Linear Mixed Effects Models were used to determine temporal trends and test demographic responses to heat stress. Temporal variation in size-frequency distributions revealed various population processes, from recruitment pulses and cohort growth, to bleaching impacts and temperature dependencies. Sporadic recruitment pulses likely support population persistence, illustrated in 2010 by strong positively skewed size-frequency distributions and the highest density of juvenile corals measured during the study. Increasing mean colony size over the following 6 yr indicates further cohort growth of these recruits. Severe heat stress in 2016 resulted in mass bleaching mortality and a 51% decline in coral density. Moderate heat stress in the following years was associated with suppressed P. aliciae recruitment and a lack of early recovery, marked by an exponential decrease of juvenile density (i.e. recruitment) with increasing heat stress. Here, population reliance on sporadic recruitment and susceptibility to heat stress underpin the vulnerability of subtropical coral assemblages to climate change.

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