title: Evolution and comparative haemoglobin oxygen binding in new zealand mudfishes

authors: Brijs, Jeroen

subjects: mudfish

abstract: New Zealand's five endemic mudfish (Neochanna spp.) species have distributions that differ both geographically and by habitat type. Differences in habitat preferences between species have led to the proposal of an evolutionary series within the group. A morphological cline can be observed from the galaxiform Chatham Island and Canterbury species inhabiting lakes and streams, respectively, to the anguilliform Northland and brown mudfishes of ephemeral wetlands. Morphological specializations proposed for wetland dwelling include loss of pelvic fins, reduced eyes, enlarged nostrils, development of caudal flanges, and elongation of dorsal and anal fin bases to become almost confluent with the caudal fin.  Another expectation of adaptation to wetland dwelling is specializations in respiratory physiology to obtain oxygen from highly hypoxic or acidic waters, and the ability to cope with seasonal exposure to air during the drought season.  Expected respiratory specializations to wetland dwelling include high oxygen affinity haemoglobins, high levels of cooperative oxygen binding, the presence of multiple haemoglobins and the ability to aestivate and survive long periods of emersion. 

The four mainland Neochanna species were examined to determine if differences in haemoglobin expression as well as differences in haemoglobin oxygen binding correlated with differing habitats and treatments.  Whole blood oxygen affinity was determined at several pH levels (6.5, 7.0, 7.5 and 8.0) and temperatures (10'C, 15'C and 20'C), as well as different treatments (aestivating, fasting and control) using a Hemox analyzer.  The presence of multiple haemoglobins was determined by isoelectric focusing.  All four species displayed high oxygen affinities (p50 = 6.5 to 9.5 mm Hg at pH 7.5  15'C), moderate levels of cooperativity (Hill coefficients = 1.75 to 2.00 at pH 7.5  15'C), pH sensitivity (Bohr coefficients = -0.62 to -0.94 between pH 7.5 and 7.0 at 15'C), temperature sensitivity (ΔH = -2.20 to -15.78 k cal mol-1 between 10'C and 15'C) and the presence of multiple haemoglobins.  Black, brown and Northland mudfish were able to survive aestivation for six weeks but there were no changes between air-breathing and water-breathing individuals with respect to oxygen binding characteristics.  Although there is evidence of habitat specialization in haemoglobin physiology between mudfish species, differences between species did not correlate with the evolutionary series proposed for specialization to dwelling in ephemeral wetlands and latitudinal distributions of mudfish species appear to strongly dictate oxygen binding properties of mudfish whole blood.

text: Evolution and comparative haemoglobin oxygen binding in new zealand mudfishes New Zealand's five endemic mudfish (Neochanna spp.) species have distributions that differ both geographically and by habitat type. Differences in habitat preferences between species have led to the proposal of an evolutionary series within the group. A morphological cline can be observed from the galaxiform Chatham Island and Canterbury species inhabiting lakes and streams, respectively, to the anguilliform Northland and brown mudfishes of ephemeral wetlands. Morphological specializations proposed for wetland dwelling include loss of pelvic fins, reduced eyes, enlarged nostrils, development of caudal flanges, and elongation of dorsal and anal fin bases to become almost confluent with the caudal fin.  Another expectation of adaptation to wetland dwelling is specializations in respiratory physiology to obtain oxygen from highly hypoxic or acidic waters, and the ability to cope with seasonal exposure to air during the drought season.  Expected respiratory specializations to wetland dwelling include high oxygen affinity haemoglobins, high levels of cooperative oxygen binding, the presence of multiple haemoglobins and the ability to aestivate and survive long periods of emersion. 

The four mainland Neochanna species were examined to determine if differences in haemoglobin expression as well as differences in haemoglobin oxygen binding correlated with differing habitats and treatments.  Whole blood oxygen affinity was determined at several pH levels (6.5, 7.0, 7.5 and 8.0) and temperatures (10'C, 15'C and 20'C), as well as different treatments (aestivating, fasting and control) using a Hemox analyzer.  The presence of multiple haemoglobins was determined by isoelectric focusing.  All four species displayed high oxygen affinities (p50 = 6.5 to 9.5 mm Hg at pH 7.5  15'C), moderate levels of cooperativity (Hill coefficients = 1.75 to 2.00 at pH 7.5  15'C), pH sensitivity (Bohr coefficients = -0.62 to -0.94 between pH 7.5 and 7.0 at 15'C), temperature sensitivity (ΔH = -2.20 to -15.78 k cal mol-1 between 10'C and 15'C) and the presence of multiple haemoglobins.  Black, brown and Northland mudfish were able to survive aestivation for six weeks but there were no changes between air-breathing and water-breathing individuals with respect to oxygen binding characteristics.  Although there is evidence of habitat specialization in haemoglobin physiology between mudfish species, differences between species did not correlate with the evolutionary series proposed for specialization to dwelling in ephemeral wetlands and latitudinal distributions of mudfish species appear to strongly dictate oxygen binding properties of mudfish whole blood.

year: 2007

title: Seasonal abundance of small cladocerans in Lake Mangakaware, Waikato, New Zealand

authors: Greenwood, Tracey L.

subjects: biology

abstract: The seasonal changes in the dynamics and life histories of the Cladocera in Lake Mangakaware, North Island, New Zealand, were studied over 19 months by sampling at weekly or 2-weekly intervals. Lake Mangakaware is a 13.3 ha polymictic lake with high nutrient status, low Secchi disc transparencies, and an unstable thermal regime. The four planktonic cladoceran species (Bosmina longirostris, B. meridionalis, Ceriodaphnia pulchella, and C. dubia) exhibited disjunct population maxima. Only B. longirostris was perennially present. All species exhibited low fecundities and low lipid content, indicating that food resources were limited and that competitive interactions and resistance to starvation were probably important in determining species success. Increases in body size in cooler seasons were unrelated to clutch size, giving further support for the view that available food was limited. These results are consistent with previous experimental findings that subtle differences in life history can determine seasonal success and the outcome of competition between similar species.

text: Seasonal abundance of small cladocerans in Lake Mangakaware, Waikato, New Zealand The seasonal changes in the dynamics and life histories of the Cladocera in Lake Mangakaware, North Island, New Zealand, were studied over 19 months by sampling at weekly or 2-weekly intervals. Lake Mangakaware is a 13.3 ha polymictic lake with high nutrient status, low Secchi disc transparencies, and an unstable thermal regime. The four planktonic cladoceran species (Bosmina longirostris, B. meridionalis, Ceriodaphnia pulchella, and C. dubia) exhibited disjunct population maxima. Only B. longirostris was perennially present. All species exhibited low fecundities and low lipid content, indicating that food resources were limited and that competitive interactions and resistance to starvation were probably important in determining species success. Increases in body size in cooler seasons were unrelated to clutch size, giving further support for the view that available food was limited. These results are consistent with previous experimental findings that subtle differences in life history can determine seasonal success and the outcome of competition between similar species.

year: 1999-03

title: New Zealand army chaplains at war : 2 NZEF 1939 - 1945

authors: Glen, Frank

abstract: This thesis investigates the motivations to engage in, and the pastoral and sacramental work of, the 1939-45 World War Two chaplains of the Second New Zealand Expeditionary Force, and it explores the theological framework, and theology in which such chaplaincy was carried out. It concludes by noting significant factors and issues of concern to chaplains and their churches in respect of the transition from war to peace.

Historical models of military chaplaincy are found in Constantine’s Roman Empire of 312-337CE, the Christian Crusades of 1096-1291, and the later British Empire. Features of these models provide a tool for understanding and interpreting many aspects of the work and role of the military chaplains of this study. The impact of Christian pacifism is considered, as it is one of the influences which came to bear upon the decision of some clergy who enlisted as chaplains.

Chaplains were recruited from eight denominations and they demonstrated a common pastoral concern for all who were engaged in the various theatres of war. Through the introduction of the concept of ecumenical unit chaplaincy, the battalion became the padre’s parish where he conducted worship, exercised pastoral skills, read the liturgies and preached the Gospel. This became the corner-stone of an ecumenical chaplaincy which developed throughout the war years. Despite the exigencies of war a Bible Class network, church parades - both voluntary and compulsory - and a wide range of religious activities contributed to a spiritual programme which met the needs of a largely nominal Christian 2NZEF.

There emerged from the experience of worship within the 2NZEF a pragmatic ecumenical approach to many aspects of chaplaincy, including in particular the practice, at least for Protestants, of inter-communion. Roman Catholic practice and theological understanding of the Eucharist was enriched by a particular New Zealand contribution. The isolation of the Pacific theatre, coupled with the maturing of the Chaplain’s Department through the Middle East experiences, resulted in a heightening of ecumenical development within the 3rd Division chaplaincy.

The chaplain’s skills in pastoral matters were required to maintain morale, cope with death, wounding and captivity. They are defined first from a military perspective and then examined from a biblical viewpoint. It is primarily in reference to chaplains’ skills associated with the battlefield context, although other situations are included, that issues of pastoral ministry are identified and discussed. The Maori chaplains’ task is discussed in reference to the tohunga of pre-Christian times. Unlike their Pakeha (European) associates. Maori chaplains had access to individuals of influence within New Zealand Maori politics, a factor which was of particular significance.

Almost all chaplains had a belief in the natural justice of World War Two and this thesis will suggest they believed that not to have embarked upon war would have led to infinitely more serious problems for both civilization and the Christian Church. Throughout the war years there was an identified and distinct implicit theological framework which underwrote their attitudes and actions. Their opinions, theological framework and ideology, regarding the war arose both from the ministerial duties they performed and their battlefield experience of war itself.

The model of New Zealand chaplaincy is defined and compared with the classical models noted at the beginning of the thesis. At the end of the war, the 2NZEF Chaplains’ Department held a series of Leadership Schools. These Schools, involving laymen of all denominations. addressed a series of transitional religious and social issues, the outcomes of which were to develop over the decades following WW2. The concluding chapter summarizes a Theology of Chaplaincy which has developed from the foregoing study.

text: New Zealand army chaplains at war : 2 NZEF 1939 - 1945 This thesis investigates the motivations to engage in, and the pastoral and sacramental work of, the 1939-45 World War Two chaplains of the Second New Zealand Expeditionary Force, and it explores the theological framework, and theology in which such chaplaincy was carried out. It concludes by noting significant factors and issues of concern to chaplains and their churches in respect of the transition from war to peace.

Historical models of military chaplaincy are found in Constantine’s Roman Empire of 312-337CE, the Christian Crusades of 1096-1291, and the later British Empire. Features of these models provide a tool for understanding and interpreting many aspects of the work and role of the military chaplains of this study. The impact of Christian pacifism is considered, as it is one of the influences which came to bear upon the decision of some clergy who enlisted as chaplains.

Chaplains were recruited from eight denominations and they demonstrated a common pastoral concern for all who were engaged in the various theatres of war. Through the introduction of the concept of ecumenical unit chaplaincy, the battalion became the padre’s parish where he conducted worship, exercised pastoral skills, read the liturgies and preached the Gospel. This became the corner-stone of an ecumenical chaplaincy which developed throughout the war years. Despite the exigencies of war a Bible Class network, church parades - both voluntary and compulsory - and a wide range of religious activities contributed to a spiritual programme which met the needs of a largely nominal Christian 2NZEF.

There emerged from the experience of worship within the 2NZEF a pragmatic ecumenical approach to many aspects of chaplaincy, including in particular the practice, at least for Protestants, of inter-communion. Roman Catholic practice and theological understanding of the Eucharist was enriched by a particular New Zealand contribution. The isolation of the Pacific theatre, coupled with the maturing of the Chaplain’s Department through the Middle East experiences, resulted in a heightening of ecumenical development within the 3rd Division chaplaincy.

The chaplain’s skills in pastoral matters were required to maintain morale, cope with death, wounding and captivity. They are defined first from a military perspective and then examined from a biblical viewpoint. It is primarily in reference to chaplains’ skills associated with the battlefield context, although other situations are included, that issues of pastoral ministry are identified and discussed. The Maori chaplains’ task is discussed in reference to the tohunga of pre-Christian times. Unlike their Pakeha (European) associates. Maori chaplains had access to individuals of influence within New Zealand Maori politics, a factor which was of particular significance.

Almost all chaplains had a belief in the natural justice of World War Two and this thesis will suggest they believed that not to have embarked upon war would have led to infinitely more serious problems for both civilization and the Christian Church. Throughout the war years there was an identified and distinct implicit theological framework which underwrote their attitudes and actions. Their opinions, theological framework and ideology, regarding the war arose both from the ministerial duties they performed and their battlefield experience of war itself.

The model of New Zealand chaplaincy is defined and compared with the classical models noted at the beginning of the thesis. At the end of the war, the 2NZEF Chaplains’ Department held a series of Leadership Schools. These Schools, involving laymen of all denominations. addressed a series of transitional religious and social issues, the outcomes of which were to develop over the decades following WW2. The concluding chapter summarizes a Theology of Chaplaincy which has developed from the foregoing study.

year: 1996