title: Long-term isolation and recent range expansion from glacial refugia revealed for the endemic springtail Gomphiocephalus hodgsoni from Victoria Land, Antarctica

authors: Stevens, Mark I.

subjects: allozymes

abstract: We examined the phylogeography of the endemic Antarctic collembolan Gomphiocephalus hodgsoni using allozymes and mitochondrial DNA (mtDNA; COI) to determine if potentially limited dispersal and long-term habitat fragmentation have promoted regional genetic differentiation. Allozyme analyses showed that differentiation among 21 populations within the Ross Dependency was high (FST = 0.55) with two main groups each representing a distinct geographical region: (1) Ross Island and Beaufort Island; and (2) all continental sites. Ross Island populations showed low levels of differentiation (FST = 0.05) and no correlation with geographical distance, suggesting their derivation from a single glacial refuge. By contrast, continental regions revealed moderate levels of differentiation (FST = 0.27) and a strong correlation with geographical distance, indicating a much older history with several refugia likely. Two sympatric allozyme genotypes were found at three continental sites from Taylor Valley and were congruent with two mtDNA haplotypes, implying nonrandom breeding groups. Although haplotype sharing between one Ross Island site (Cape Bird) and one continental site (Granite Harbour) was identified, the clades showed mostly fragmented allopatric distributions. The extensive Pleistocene glaciations, in conjunction with limited dispersal opportunities, appear to have promoted isolation and divergence among the fragmented habitats. Furthermore, the McMurdo Sound appears to be an effective isolating barrier to dispersal. However, we suggest that the unaided dispersal capacity of G. hodgsoni is unlikely to account for the limited mixing of haplotypes across the McMurdo Sound and recent human- or bird-mediated dispersal is highly probable.

text: Long-term isolation and recent range expansion from glacial refugia revealed for the endemic springtail Gomphiocephalus hodgsoni from Victoria Land, Antarctica We examined the phylogeography of the endemic Antarctic collembolan Gomphiocephalus hodgsoni using allozymes and mitochondrial DNA (mtDNA; COI) to determine if potentially limited dispersal and long-term habitat fragmentation have promoted regional genetic differentiation. Allozyme analyses showed that differentiation among 21 populations within the Ross Dependency was high (FST = 0.55) with two main groups each representing a distinct geographical region: (1) Ross Island and Beaufort Island; and (2) all continental sites. Ross Island populations showed low levels of differentiation (FST = 0.05) and no correlation with geographical distance, suggesting their derivation from a single glacial refuge. By contrast, continental regions revealed moderate levels of differentiation (FST = 0.27) and a strong correlation with geographical distance, indicating a much older history with several refugia likely. Two sympatric allozyme genotypes were found at three continental sites from Taylor Valley and were congruent with two mtDNA haplotypes, implying nonrandom breeding groups. Although haplotype sharing between one Ross Island site (Cape Bird) and one continental site (Granite Harbour) was identified, the clades showed mostly fragmented allopatric distributions. The extensive Pleistocene glaciations, in conjunction with limited dispersal opportunities, appear to have promoted isolation and divergence among the fragmented habitats. Furthermore, the McMurdo Sound appears to be an effective isolating barrier to dispersal. However, we suggest that the unaided dispersal capacity of G. hodgsoni is unlikely to account for the limited mixing of haplotypes across the McMurdo Sound and recent human- or bird-mediated dispersal is highly probable.

year: 2010

title: Reproductive investment and strategies of Gobiomorphus cotidianus

authors: Pepper, Kate Louise

subjects: Gobiomorphus cotidianus

abstract: The New Zealand common bully (Gobiomorphus cotidianus) is a member of the family Eleotridae which comprises around 35 genera and some 150 species worldwide. G. cotidianus are abundant throughout New Zealand and thrive in streams, large rivers and lakes, with broad tolerances for temperature, pH, flow and lake trophic status. It is known that male bullies clean and guard a nest site and attract one or possibly more females to spawn within the nest which is then guarded until the eggs hatch. However, due to intraspecific competition, some males miss out. Male alternative reproductive tactics (MARTs) are commonly used to achieve a successful reproductive outcome when the usual reproductive strategy becomes energetically inefficient for the individual. MART’s are common within the closely related family Gobiidae but have not yet been observed in the Eleotridae.
Differential investments in gonadal mass versus parental care are known in many animals from fish to humans. Greater parental investment typically correlates with smaller gonad size. I investigated the relative investment made by male common bully in gonads versus seminal vesicles on the assumption that if non-guarding (parasitic) males occur, they would invest significantly less effort in seminal vesicles (SVs) compared with “bourgeois” (nest guarding) males. I examined these traits monthly to determine possible seasonal changes in reproductive strategies. We found that male investment in SVs does vary significantly between individuals and that the greatest investment in this structure in males coincides with the peak summer breeding season. A small proportion of males (usually larger individuals) invest heavily in SVs but it is currently unknown whether these, and only these, defend nest sites and whether the remainder rely on MART strategies for reproductive success. Seminal vesicle size was positively correlated with fish size whereas testis size declined with increasing size of males.
Sampling of common bully from Lake Karapiro began in December 2013 and finished in January 2015 providing fourteen months of data to
predominantly investigate male reproductive investment using calculations of gonadosomatic index (GSI) and seminal vesicle somatic index (SVSI).
I found that although investment in both gonads and seminal vesicles increase in preparation for the breeding season, the increase in SVSI is considerably greater than the comparatively slight increase in GSI. I also examined female GSI and found that it followed similar trends to that of the SVSI with sharp increases occurring throughout late winter and spring.
Calculations of somatic condition indices were made for both males and females throughout the 14 month sampling period. This identified similar condition trends for both sexes with peaks throughout summer suggesting a slight increase in somatic condition post-breeding season. Male condition was slightly higher and more varied during this summer period.
A behavioural experiment was carried out to investigate male nest preference and guarding behaviour. Obvious nest guarding was displayed in 14 of the 40 nest arenas and 11 of the guarded nests were large pots compared with only 3 guarded small pots. GSI and SVSI data from the males within the experiment suggest an increased investment in seminal vesicles by males displaying nest guarding behaviour. However, the sample size for both of these elements was too small to provide statistically significant results.

text: Reproductive investment and strategies of Gobiomorphus cotidianus The New Zealand common bully (Gobiomorphus cotidianus) is a member of the family Eleotridae which comprises around 35 genera and some 150 species worldwide. G. cotidianus are abundant throughout New Zealand and thrive in streams, large rivers and lakes, with broad tolerances for temperature, pH, flow and lake trophic status. It is known that male bullies clean and guard a nest site and attract one or possibly more females to spawn within the nest which is then guarded until the eggs hatch. However, due to intraspecific competition, some males miss out. Male alternative reproductive tactics (MARTs) are commonly used to achieve a successful reproductive outcome when the usual reproductive strategy becomes energetically inefficient for the individual. MART’s are common within the closely related family Gobiidae but have not yet been observed in the Eleotridae.
Differential investments in gonadal mass versus parental care are known in many animals from fish to humans. Greater parental investment typically correlates with smaller gonad size. I investigated the relative investment made by male common bully in gonads versus seminal vesicles on the assumption that if non-guarding (parasitic) males occur, they would invest significantly less effort in seminal vesicles (SVs) compared with “bourgeois” (nest guarding) males. I examined these traits monthly to determine possible seasonal changes in reproductive strategies. We found that male investment in SVs does vary significantly between individuals and that the greatest investment in this structure in males coincides with the peak summer breeding season. A small proportion of males (usually larger individuals) invest heavily in SVs but it is currently unknown whether these, and only these, defend nest sites and whether the remainder rely on MART strategies for reproductive success. Seminal vesicle size was positively correlated with fish size whereas testis size declined with increasing size of males.
Sampling of common bully from Lake Karapiro began in December 2013 and finished in January 2015 providing fourteen months of data to
predominantly investigate male reproductive investment using calculations of gonadosomatic index (GSI) and seminal vesicle somatic index (SVSI).
I found that although investment in both gonads and seminal vesicles increase in preparation for the breeding season, the increase in SVSI is considerably greater than the comparatively slight increase in GSI. I also examined female GSI and found that it followed similar trends to that of the SVSI with sharp increases occurring throughout late winter and spring.
Calculations of somatic condition indices were made for both males and females throughout the 14 month sampling period. This identified similar condition trends for both sexes with peaks throughout summer suggesting a slight increase in somatic condition post-breeding season. Male condition was slightly higher and more varied during this summer period.
A behavioural experiment was carried out to investigate male nest preference and guarding behaviour. Obvious nest guarding was displayed in 14 of the 40 nest arenas and 11 of the guarded nests were large pots compared with only 3 guarded small pots. GSI and SVSI data from the males within the experiment suggest an increased investment in seminal vesicles by males displaying nest guarding behaviour. However, the sample size for both of these elements was too small to provide statistically significant results.

year: 2015

title: Ngā Tuituinga o te Pōtae: Rangatahi perspectives of leadership within Ngāti Maniapoto

authors: Moss, Luke

subjects: Rangatahi

abstract: Research on youth leadership development is often saturated by adult perceptions and thus the literature often lacks youth voice and youth perspective on what integral areas are needed for successful youth leadership development. This research focuses on the rangatahi of Ngāti Maniapoto and their perspectives of leadership within the iwi to aid the gap in academic literature relating to youth perception of leadership development.

Maniapoto has an abundance of leadership examples from the plethora of tūpuna that have developed the iwi to the leaders of contemporary Maniapoto pushing the iwi forward. The purpose of this research is to delve into the perspectives of rangatahi Maniapoto that pertain to good leadership qualities, their perception of leadership, unique leadership styles within Maniapoto, rangatahi leadership skills and perspectives of youth development within the iwi. By interviewing rangatahi with strong connection to Maniapoto this information of their perspectives revealed four integral areas of rangatahi leadership development were collated into a model for dissemination and use within the iwi for youth development practices. This model is named Ngā Tuituinga o te Pōtae and has four areas, education, collective, communication and vision. Education was identified by rangatahi as they found that learning Maniapoto reo and tikanga was integral for a Maniapoto leader, in addition they saw an opportunity to establish a wānanga to future proof our Maniapototanga. A collective approach to leadership was highlighted as the rangatahi perceive that Maniapoto leaders need to be well known in the community and have good relationships with iwi members to be successful. Rangatahi reported that communication was an important attribute for leaders to have, not just speech but communicating by doing was essential for a Maniapoto leader. Finally, rangatahi explained that leaders need to have a vision for the taiao and a vision for our people to be a successful leader, and be able to take the iwi to a place they have not been to before.

This study adds to the scarce literature on youth perceptions on youth leadership development and definitively answers the question on how rangatahi of Maniapoto perceive leadership and how rangatahi of Maniapoto would develop leadership within Te Nehenehenui. The key findings presented in this thesis indicate that rangatahi from Maniapoto engage and identify leadership in many ways, however they do agree that leadership development is necessary for Maniapoto to flourish in the future. Applying this model and research within the iwi will create new foundations for leadership to grow within Maniapoto, and fill the gap of leadership for the iwi that rangatahi have identified.

text: Ngā Tuituinga o te Pōtae: Rangatahi perspectives of leadership within Ngāti Maniapoto Research on youth leadership development is often saturated by adult perceptions and thus the literature often lacks youth voice and youth perspective on what integral areas are needed for successful youth leadership development. This research focuses on the rangatahi of Ngāti Maniapoto and their perspectives of leadership within the iwi to aid the gap in academic literature relating to youth perception of leadership development.

Maniapoto has an abundance of leadership examples from the plethora of tūpuna that have developed the iwi to the leaders of contemporary Maniapoto pushing the iwi forward. The purpose of this research is to delve into the perspectives of rangatahi Maniapoto that pertain to good leadership qualities, their perception of leadership, unique leadership styles within Maniapoto, rangatahi leadership skills and perspectives of youth development within the iwi. By interviewing rangatahi with strong connection to Maniapoto this information of their perspectives revealed four integral areas of rangatahi leadership development were collated into a model for dissemination and use within the iwi for youth development practices. This model is named Ngā Tuituinga o te Pōtae and has four areas, education, collective, communication and vision. Education was identified by rangatahi as they found that learning Maniapoto reo and tikanga was integral for a Maniapoto leader, in addition they saw an opportunity to establish a wānanga to future proof our Maniapototanga. A collective approach to leadership was highlighted as the rangatahi perceive that Maniapoto leaders need to be well known in the community and have good relationships with iwi members to be successful. Rangatahi reported that communication was an important attribute for leaders to have, not just speech but communicating by doing was essential for a Maniapoto leader. Finally, rangatahi explained that leaders need to have a vision for the taiao and a vision for our people to be a successful leader, and be able to take the iwi to a place they have not been to before.

This study adds to the scarce literature on youth perceptions on youth leadership development and definitively answers the question on how rangatahi of Maniapoto perceive leadership and how rangatahi of Maniapoto would develop leadership within Te Nehenehenui. The key findings presented in this thesis indicate that rangatahi from Maniapoto engage and identify leadership in many ways, however they do agree that leadership development is necessary for Maniapoto to flourish in the future. Applying this model and research within the iwi will create new foundations for leadership to grow within Maniapoto, and fill the gap of leadership for the iwi that rangatahi have identified.

year: 2021