Using traditional age and growth techniques in endangered species management: eastern freshwater cod, Maccullochella ikei

2008 ◽  
Vol 59 (8) ◽  
pp. 684 ◽  
Author(s):  
Gavin L. Butler ◽  
Stuart J. Rowland
Keyword(s):  
New South ◽  
Age And Growth ◽  
Growth Equation ◽  
Endangered Species Management ◽  
South Wales ◽  
Traditional Age ◽  
Von Bertalanffy Growth Equation ◽  
Relationship Of ◽  
Non Destructive ◽  
Age Estimates

Age and growth estimates can be difficult to obtain for endangered fishes owing to their relative low abundance and the ethics associated with sampling threatened populations. The eastern freshwater cod, Maccullochella ikei Rowland 1985, is an endangered freshwater fish endemic to the Clarence and Richmond Rivers of New South Wales, Australia. Bony parts were gathered from archival collections and hatcheries, as well as opportunistically from the wild, to determine age and growth. Examination of opercular bones and dorsal spine sections revealed no consistent annuli. Sectioned otoliths exhibited consistent bipartite rings throughout the structures and 106 otoliths were used to estimate the age of cod from 0+ to 15+ years. Edge increment analysis and known-age cod were used to validate the age estimates. The von Bertalanffy growth equation for M. ikei is Lt = 704.9 (1–exp (–0.20 (t + 0.14))). A length–weight relationship of W = 2.80 × 10–6 × L3.2467 was established from 372 cod collected using non-destructive techniques. Significant differences were found in the relative condition of cod in summer (Kn = 0.999) and winter (Kn = 1.026). The information presented in this paper will assist in the conservation of M. ikei and will provide a guide for future age and growth studies of threatened species.

Age and growth of Freshwater Herring, Potamalosa richmondia Macleay (Clupeidae: Hyperlophinae), in the Bellinger River, NSW

1989 ◽  
Vol 40 (6) ◽  
pp. 679 ◽  
Author(s):  
RWJ Pidgeon
Keyword(s):  
New South ◽  
Age And Growth ◽  
Growth Equation ◽  
Von Bertalanffy ◽  
Age Classes ◽  
South Wales ◽  
Marginal Increment ◽  
Males And Females ◽  
Von Bertalanffy Growth Equation ◽  
One Year

The freshwater herring, Potamalosa richmondia Macleay, is a catadromous fish that inhabits coastal rivers of New South Wales. Estimates of the age and growth of this species in the Bellinger River were made from scales. Comparison of scale ages with those from whole otoliths and burnt otolith sections from a sample of 30 fish aged at 2 to 8 years resulted in a 73 and 79% exact agreement and a 97 and 100% agreement within one year, respectively. Marginal-increment analysis of the scales indicated that the annulus was formed during the winter, which is also the spawning season. The ageing method was validated for age classes of 2 to 8 years by these procedures. The age at the first annulus and at ages 9 to 11 years could not be validated. The oldest fish examined was estimated to be 11 years old. The growth rate was very slow in comparison with that of other clupeids. Parameters of the von Bertalanffy growth equation, based on lengths and ages at capture, were L∞ = 252.7 mm, K = 0.126, and t0 = -2.77 years. There was no difference between the sexes in their growth in length. However, the length-weight relationships of males and females were different, with females longer than 180 mm weighing more than males of the same length. The predicted weights at the asymptotic length were 213.2 g for males and 257.6 g for females.

scholarly journals Age and growth of bluemouth, Helicolenus dactylopterus, from the Portuguese continental slope

2009 ◽  
Vol 66 (3) ◽  
pp. 524-531 ◽  
Author(s):  
Vera Sequeira ◽  
Ana Neves ◽  
Ana Rita Vieira ◽  
Ivone Figueiredo ◽  
Leonel S. Gordo
Keyword(s):  
Continental Slope ◽  
Growth Increment ◽  
Age And Growth ◽  
Growth Equation ◽  
Daily Growth ◽  
Class 1 ◽  
Helicolenus Dactylopterus ◽  
The Mean ◽  
Von Bertalanffy Growth Equation ◽  
Age Estimates

Abstract Sequeira, V., Neves, A., Vieira, A. R., Figueiredo, I., and Gordo, L. S. 2009. Age and growth of bluemouth, Helicolenus dactylopterus, from the Portuguese continental slope. – ICES Journal of Marine Science, 66: 524–531. In all, 933 bluemouth (Helicolenus dactylopterus) were obtained from bottom-trawl research surveys along the Portuguese continental slope between October 2005 and February 2007 and from commercial landings. Age was determined by reading whole sagittal otoliths, and age estimates were validated by daily growth increment (DGI) analysis. Fish ranged from 5.2 to 44.9 cm, which corresponded to fish between 0 and 30 years old. The mean total length obtained from DGI analysis for age class 1 fish was 8.6 cm, corresponding to otoliths with a mean radius of 1.8 mm. As no statistical differences between sex were observed, the von Bertalanffy growth equation fitted was Lt = 45.50[1 − e−0.05(t+4.01)]. Comparisons with other studies using Hotelling's T2 test and the growth perform index (Ф) are drawn. The growth rates estimated in this study using whole otolith readings were the lowest of all the studies available, and the estimated L∞ is lower then those obtained for Azorean waters and higher than those published for the Mediterranean.

Age and growth pattern of the thin-lipped mullet Liza Ramada in the Eastern coast of Libya.

2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor
Keyword(s):  
Frequency Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Growth Equation ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Scale Reading ◽  
Von Bertalanffy Growth Equation

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.

Use of stereo baited remote underwater video systems to estimate the presence and size of white sharks (Carcharodon carcharias)

2017 ◽  
Vol 68 (7) ◽  
pp. 1391 ◽  
Author(s):  
D. Harasti ◽  
K. A. Lee ◽  
R. Laird ◽  
R. Bradford ◽  
B. Bruce
Keyword(s):  
Relative Abundance ◽  
Fish Assemblages ◽  
New South ◽  
Underwater Video ◽  
Carcharodon Carcharias ◽  
South Wales ◽  
Video Systems ◽  
Near Shore ◽  
Number Of Individuals ◽  
Non Destructive

Stereo baited remote underwater video systems (stereo-BRUVs) are commonly used to assess fish assemblages and, more recently, to record the localised abundance and size of sharks. The present study investigated the occurrence and size of white sharks (Carcharodon carcharias) in the near-shore environment off Bennett’s Beach, part of a known nursery area for the species in central New South Wales, Australia. Six stereo-BRUV units were deployed approximately fortnightly between August and December 2015 for periods of 5h in depths of 7–14m. Stereo-BRUVs successfully recorded 34 separate sightings of 22 individual white sharks. The highest number of individuals detected during a single day survey was eight. All C. carcharias observed on stereo-BRUVs were juveniles ranging in size from 1.50 to 2.46-m total length (mean±s.e., 1.91±0.05m; n=22). The time to first appearance ranged from 15 to 299min (mean±s.e., 148±15min). This study demonstrates that the use of stereo-BRUVs is a viable, non-destructive method to obtain estimates of the size and presence of white sharks, and may be useful in estimating relative abundance in near-shore environments where white sharks are known to frequent.

scholarly journals Somatic growth and age of selected commercial fish species of the Cullera Coast, Iberian Peninsula, south-east Spain

2019 ◽  
Vol 66 (3) ◽  
Author(s):  
Angela Maria Jaramillo-Londono ◽  
Alejandra Vanina Volpedo ◽  
Jose Luis Diaz-Arevalo ◽  
Maria Eugenia Rodrigo-Santamalia ◽  
Vicent Bendito-Dura
Keyword(s):  
Fish Species ◽  
Somatic Growth ◽  
Mesh Size ◽  
Age And Growth ◽  
Biological Information ◽  
Growth Equation ◽  
Commercial Fish ◽  
Mullus Surmuletus ◽  
Von Bertalanffy Growth Equation ◽  
Uranoscopus Scaber

This work provides data on the somatic growth and age of selected commercial fish species of the Cullera Coast, Spain. The biological information available that permits responsible fishing management of these species is relatively scarce. This study was conducted in the Bay of Cullera, Spain (39º 12’to 38º 59’N, and 0º 09’to 0º 15’W); and selected benthic fish species were analysed that are frequently fished by trammel nets (mesh size 28-76 mm) at a maximum depth of 30 m. Maturity , age and growth of 63 torpedoes, Torpedo torpedo (L., 1758), 115 red scorpionfish, Scorpaena scrofa Linnaeus, 1758, 280 red mullets, Mullus surmuletus Linnaeus, 1758, 139 stargazers, Uranoscopus scaber Linnaeus, 1758, and 476 Portuguese soles, Dagetichthys lusitanicus de Brito Capello, 1868 were analysed. The data obtained in this study revealed that 50% of individuals of all the species reached sexual maturity at a TL (total length) of 20.0-36.5 cm and at an age of 2-6 years. The von Bertalanffy growth equation derived were: TL=37.0 (1 - e(-0.2(t + 0.33))); TL =31.5(1 - e(-0.38(t + 0.54))); TL =35.5(1 - e(-0.2(t + 2.08))); and TL =34.3(1 - e(-0.14(t + 2.16))) for S. scrofa, M. surmuletus; U. scaber and D. lusitanicus respectively.

British Bravery, or Tars Triumphant: Images of the British Navy in Nautical Melodrama

1988 ◽  
Vol 4 (14) ◽  
pp. 122-143 ◽  
Author(s):  
Jim Davis
Keyword(s):  
Nineteenth Century ◽  
New South ◽  
Real Life ◽  
Theatre History ◽  
Popular Theatre ◽  
South Wales ◽  
Theatre Studies ◽  
The University ◽  
Relationship Of ◽  
The Relationship

In recent years, melodrama has increasingly been recognized not only as an important element in popular theatre studies, but for the intrinsic importance of the form itself. Less considered has been the relationship of the material of melodrama to the ‘real life’ it reflected in a highly conventionalized yet ultimately (for its audiences), recognizable fashion. Here, Jim Davis looks at one major category, nautical melodrama, setting the images of the navy and of sailors that it created alongside factual and critical accounts of life at sea in the first half of the nineteenth century. He conveys both the pressures that existed for redress of abuses, and the consequent balance between coercion and subversion in the melodramas themselves – drawing in particular on the memoirs of Douglas Jerrold to explore aspects of the ambiguity to be found in contemporary attitudes. Jim Davis, who is the author of several books and articles in the area of nineteenth century theatre history, is presently teaching in the School of Theatre Studies at the University of New South Wales.

Feeding ecology, growth and sexual cycle of the sand sole, Solea lascaris, along the Portuguese coast

2009 ◽  
Vol 89 (3) ◽  
pp. 621-627 ◽  
Author(s):  
Célia M. Teixeira ◽  
Ana Pinheiro ◽  
Henrique N. Cabral
Keyword(s):  
Feeding Habits ◽  
Gonadosomatic Index ◽  
Age And Growth ◽  
Sexual Cycle ◽  
Growth Equation ◽  
Von Bertalanffy ◽  
Portuguese Coast ◽  
Important Prey ◽  
Von Bertalanffy Growth Equation ◽  
Prey Items

Sand sole, Solea lascaris, were collected along the Portuguese coast, between October 2002 and July 2003, to examine feeding habits, age and growth and sexual cycle. The most important prey items were Mysidacea, Amphipoda and Polychaeta. Differences in diet according to season and length size were found: Amphipoda were very important in diet during winter, while Echinodermata were consumed mostly in summer; smaller individuals feed on Amphipoda while larger feed on Decapoda. Age of S. lascaris was determined from sagittae otoliths. The length of fish analysed ranged from 61 mm to 340 mm. The von Bertalanffy growth equation parameters differed significantly between sexes (L∞ = 342.3 mm, k = 0.50, t0 = −0.87 and L∞ = 264.5 mm, k = 0.82, t0 = 0.13, females and males, respectively). The highest values of the gonadosomatic index were obtained in winter and spring, when the highest proportion of individuals at spawning stage was recorded.

Polythrinciopsis Gen.Nov, (Fungi Imperfecti) on Phragmites communis Trin

1966 ◽  
Vol 14 (2) ◽  
pp. 195 ◽  
Author(s):  
J Walker
Keyword(s):  
Leaf Spot ◽  
Type Species ◽  
New Genus ◽  
New South ◽  
Phragmites Communis ◽  
Leaf Spots ◽  
South Wales ◽  
Relationship Of ◽  
The Relationship ◽  
Fungi Imperfecti

The new genus Polythrinciopsis, with the type species P. phragmitis, is described from a leaf spot of Phragmites communis Trin, in eastern New South Wales. The genus is characterized by hypophyllous conidiophores, which develop in clusters from a few fungal cells in the stomatal opening and which show a strongly unilateral placement of spore scars; by large, hyaline to very pale olivaceous, two-celled, acrogenous conidia; and by an abundant superficial mycelium developing on the under side of the leaf spots. The relationship of this fungus to some other genera of the Fungi Imperfecti is discussed.

Preliminary observations on the effect of removal of black bluebush (Maireana pyramidata) and Pearl Bluebush (M. sedifolia) on shrub regeneration, herbage production and erosion potential.

1985 ◽  
Vol 7 (2) ◽  
pp. 103
Author(s):  
GJ Tupper ◽  
WJ Muller
Keyword(s):  
Wind Erosion ◽  
New South ◽  
Soil Surface ◽  
Critical Value ◽  
Mechanical Removal ◽  
South Wales ◽  
Erosion Index ◽  
Relationship Of ◽  
The Relationship ◽  
Over Time

The effects of mechanical removal of shrub tops and grazing on two bluebush communities, one with Maireana pyramidata (black bluebush)and the other with M. pyramidata and M. sedifolia (pearl bluebush) as co-dominants, were examined on the western edge of the Riverine Plain in New South Wales Measurements were made on shrub regeneration, the relationship of shrub units to a critical value for an erosion index, the change in soil surface levels, and the growth of herbaceous plants over time Shrub regeneration was slower under grazed than ungrazed conditions and occurred mainly from basal shoots of established plants rather than from seedling establishment. Herbage yields Increased on the mounds previously occupied by shrubs, whereas production between shrubs was not affected by shrub removal. After four years there was sufficient shrub growth to prevent wind erosion, except on the cleared and grazed plot at the M. sedifolia site.

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