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1.
J Fish Biol ; 78(5): 1529-44, 2011 May.
Article in English | MEDLINE | ID: mdl-21539557

ABSTRACT

The influence of freshwater inflows and salinity on spawning success of black bream Acanthopagrus butcheri (Sparidae) was investigated over 2 years in a small estuary on the east coast of Tasmania, Australia. The individual spawning seasons experienced quite different freshwater inflows; 2004-2005 was characterized by low flows throughout the season whereas during 2005-2006 there were three relatively large discharge events in the first part of the season. Macroscopic gonad staging of adults was used to define the spawning season and daily increment analysis of otoliths from recently settled recruits was used to backcalculate spawning dates. Gonad staging indicated that adults were in spawning condition over a 3 to 4 month period during spring and summer. The timing and duration of successful spawning, however, differed markedly between years and was linked to the timing of freshwater inflows and salinity conditions, with successful spawning occurring during periods of low freshwater discharge and when salinities in the upper estuary were above c. 15. Growth rates of the recently settled recruits did not differ between years, nor did the timing of spawning within the season influence growth rates. While the latter finding was unexpected, especially given within season temperature variability, these results imply that by the onset of winter earlier spawned fish would be larger than later spawned individuals, potentially conferring advantages for survival and competition for food. Climate change predictions for eastern Tasmania indicate a decrease in river flows in spring and an increase during summer, potentially increasing environmental variability between and within years, with implications for spawning success and subsequent recruitment.


Subject(s)
Fresh Water , Perciformes/physiology , Reproduction/physiology , Salinity , Water Movements , Animals , Environment , Female , Male , Perciformes/growth & development , Tasmania
2.
Braz. j. microbiol ; 42(1): 282-289, Jan.-Mar. 2011. tab
Article in English | LILACS | ID: lil-571401

ABSTRACT

Columnaris disease is one of the main causes of mortality in tilapia rearing and is responsible for large economic losses worldwide. Hematology is a tool that makes it possible to study organisms' physiological responses to pathogens. It may assist in making diagnoses and prognoses on diseases in fish populations. The hematological variables of nile tilapia were studied in specimens with a clinical diagnosis of columnaris disease and in specimens that were disease-free. The total erythrocyte count, hemoglobin rate, hematocrit percentage, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), organic defense blood cell percentages (leukocytes and thrombocytes) and hepatosomatic and splenosomatic index were determined. The results showed that there were changes in the erythrocytic series and in organic defense blood cells, in the fish infected with the bacterium, with reductions in erythrocytic variables and significant increases in the numbers of circulating lymphocytes and neutrophils.


Subject(s)
Animals , Blood Cell Count , Cichlids , Flavobacteriaceae Infections , Flavobacterium , Hematology/methods , Diagnostic Techniques and Procedures , Fishes , Hematocrit , Methods
3.
Braz J Microbiol ; 42(1): 282-9, 2011 Jan.
Article in English | MEDLINE | ID: mdl-24031633

ABSTRACT

Columnaris disease is one of the main causes of mortality in tilapia rearing and is responsible for large economic losses worldwide. Hematology is a tool that makes it possible to study organisms' physiological responses to pathogens. It may assist in making diagnoses and prognoses on diseases in fish populations. The hematological variables of nile tilapia were studied in specimens with a clinical diagnosis of columnaris disease and in specimens that were disease-free. The total erythrocyte count, hemoglobin rate, hematocrit percentage, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), organic defense blood cell percentages (leukocytes and thrombocytes) and hepatosomatic and splenosomatic index were determined. The results showed that there were changes in the erythrocytic series and in organic defense blood cells, in the fish infected with the bacterium, with reductions in erythrocytic variables and significant increases in the numbers of circulating lymphocytes and neutrophils.

4.
J Fish Biol ; 77(3): 643-60, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20701645

ABSTRACT

Movement patterns and habitat utilization by black bream Acanthopagrus butcheri (Sparidae), an estuarine resident species, were investigated using acoustic telemetry in a small estuary on the east coast of Tasmania, Australia. Thirty-four adult A. butcheri were tracked for periods of up to 187 days between August 2005 and January 2006. Although able to tolerate a wide range of salinities, the fish spent most of the time within the upper and middle regions of the estuary, where brackish conditions dominated. The species exhibited extensive movements linked to tidal cycles, with small-scale upstream movements during incoming tides and downstream movements during out going tides. The extent of these movements was positively correlated with the tidal height difference between consecutive tidal peaks and troughs. Freshwater inflows and resultant changes in salinity also significantly influenced distribution and movement patterns. Fish moved downstream during the periods of heavy inflows, returning upstream as salinities increased to c. >10. During the peak of spawning period (November to December) fish moved into the upper region of the estuary, where they aggregated to spawn. Periodic increases in freshwater discharge, however, resulted in fish leaving the spawning grounds and moving downstream. Towards the end of the spawning season (January), the fish became more dispersed throughout the entire estuarine system.


Subject(s)
Ecosystem , Fresh Water , Perciformes/physiology , Swimming/physiology , Water Movements , Analysis of Variance , Animals , Seawater
5.
Int Surg ; 93(4): 226-32, 2008.
Article in English | MEDLINE | ID: mdl-19731858

ABSTRACT

It is an unresolved issue whether various thoracotomies affect clinical outcomes. In addition, a wide variety of technical approaches of video-assisted thoracic surgery depend on the facility. We reviewed 152 consecutive patients with clinical T1N0M0 lung cancer that underwent three types of lobectomy with systematic mediastinal lymphadenectomy in a single institute: 46 conventional thoracotomies (OPEN), 50 anterolateral small thoracotomies mainly using the thoracoscope as a light guide (ASSIST), and 56 minimum thoracotomies in which only a thoracoscope view was used (PURE). Total discharge from the chest drainage tube, length of hospital stay, and post-thoracotomy pain were significantly less in PURE than in OPEN and ASSIST. The results of mediastinal lymphadenectomy were equivalent. The 3-year survival rates were also similar among the three groups. We conclude that good clinical outcomes, especially reduced post-thoracotomy pain, seemed to correlate with the lesser degree of destruction of the chest wall with the identical quality as an acceptable cancer operation in PURE.


Subject(s)
Carcinoma, Non-Small-Cell Lung/surgery , Lung Neoplasms/surgery , Thoracic Surgery, Video-Assisted/methods , Adult , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/mortality , Carcinoma, Non-Small-Cell Lung/pathology , Female , Humans , Lung Neoplasms/mortality , Lung Neoplasms/pathology , Lymph Node Excision , Male , Middle Aged , Neoplasm Staging , Survival Analysis , Treatment Outcome
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