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: Exploring consumer’s preferences for farmed sea bream

authors: Stefani, Gianluca

subjects: Consumer preferences

abstract: Sea bream (Sparus aurata) production plays a significant part in Italian aquaculture, contributing to almost 18% of national pisciculture sales revenue. In recent years, Italian firms faced higher competition from countries with lower production costs. This prompted responses toward both cost reduction and product differentiation. The objective of this study was to investigate the preferences of Italian consumers for sea bream from fish farms, with a focus on aspects of product differentiation as gleaned from the analysis of the market situation: price, product origin, type and place of fish farming, and, in particular, type of feed. Data were collected with a consumers' survey using personal interviews conducted on a questionnaire that included a choice experiment. Consumer preferences were analyzed with choice models based on stated preference data. The models made it possible to evaluate the potential of products with different combinations of attributes for which there is currently no market information available. In particular, the country of origin emerged as an important element of consumer choice, and to a lesser degree, organic certification and fish farming in marine cages also play a relevant role and may command a price premium

text: Exploring consumer’s preferences for farmed sea bream Sea bream (Sparus aurata) production plays a significant part in Italian aquaculture, contributing to almost 18% of national pisciculture sales revenue. In recent years, Italian firms faced higher competition from countries with lower production costs. This prompted responses toward both cost reduction and product differentiation. The objective of this study was to investigate the preferences of Italian consumers for sea bream from fish farms, with a focus on aspects of product differentiation as gleaned from the analysis of the market situation: price, product origin, type and place of fish farming, and, in particular, type of feed. Data were collected with a consumers' survey using personal interviews conducted on a questionnaire that included a choice experiment. Consumer preferences were analyzed with choice models based on stated preference data. The models made it possible to evaluate the potential of products with different combinations of attributes for which there is currently no market information available. In particular, the country of origin emerged as an important element of consumer choice, and to a lesser degree, organic certification and fish farming in marine cages also play a relevant role and may command a price premium

year: 2012

title: What Do Secondary School Rugby Players Think About Concussion?

authors: Murphy, Karen Jane

subjects: rugby

abstract: Traumatic Brain Injury (TBI) is a dominant and growing public health concern globally. Sport is an arena in which people are at high risk of TBI. In New Zealand the popular sport of rugby is played by many, particularly during school years. These school aged players are at particular risk of TBI because of the contact nature of the sport and the maturational stage of the brain which is still developing during the teenage years.  Moves to increase safety depend on an awareness of what these players know about TBI and their attitude towards TBI.
A sample of 456 secondary school rugby players in New Zealand were surveyed to gather information about their knowledge of, and attitude towards concussion. Rugby union and rugby league playing participants were mainly recruited through direct contact with schools. Participants were invited to access the survey online or could complete a paper copy. The survey was made up of items which had already been used in previous studies and this allowed for a comparison of findings with previous research. Some items related to knowledge of concussion while others related to attitude towards concussion, in particular attitudes to returning to play following concussion.
	Participants had good knowledge of symptoms, and almost all participants knew there was a risk to long term health and a risk of death if a second concussion was sustained before a first concussion had healed. However, there were some gaps in knowledge about treatment and recovery time.
Participants self-reported attitudes to concussion were consistently and significantly safer than the attitudes they predicted ‘most players’ would hold.
More than half of the participants had a relatively safe attitude to all but one of the items relating to concussion attitude. The least safe attitudes were around who should make a decision to returning to play after concussion and the safety of attitudes declined as the importance of a rugby match increased. 
Ethnicity consistently influenced knowledge and attitude on all the measures used within the survey. Those identifying as Māori ethnicity scored lower on all knowledge and attitude scales than those identifying as Pakeha ethnicity. Self-rated knowledge of concussion and the number of concussions experienced also had a positive effect on knowledge of concussion. 
There are several educational tools and regulatory documents aimed at minimising the incidence, severity and outcome of concussion in rugby but there is little research guiding how these resources are tailored to their intended audience in the secondary school population. Also, little is known about the gaps in knowledge and understanding of concussion in this population. It is tentatively stated that the findings from this study could be used to inform strategies which are aimed at increasing knowledge and making attitudes safer in secondary school rugby players in New Zealand.

text: What Do Secondary School Rugby Players Think About Concussion? Traumatic Brain Injury (TBI) is a dominant and growing public health concern globally. Sport is an arena in which people are at high risk of TBI. In New Zealand the popular sport of rugby is played by many, particularly during school years. These school aged players are at particular risk of TBI because of the contact nature of the sport and the maturational stage of the brain which is still developing during the teenage years.  Moves to increase safety depend on an awareness of what these players know about TBI and their attitude towards TBI.
A sample of 456 secondary school rugby players in New Zealand were surveyed to gather information about their knowledge of, and attitude towards concussion. Rugby union and rugby league playing participants were mainly recruited through direct contact with schools. Participants were invited to access the survey online or could complete a paper copy. The survey was made up of items which had already been used in previous studies and this allowed for a comparison of findings with previous research. Some items related to knowledge of concussion while others related to attitude towards concussion, in particular attitudes to returning to play following concussion.
	Participants had good knowledge of symptoms, and almost all participants knew there was a risk to long term health and a risk of death if a second concussion was sustained before a first concussion had healed. However, there were some gaps in knowledge about treatment and recovery time.
Participants self-reported attitudes to concussion were consistently and significantly safer than the attitudes they predicted ‘most players’ would hold.
More than half of the participants had a relatively safe attitude to all but one of the items relating to concussion attitude. The least safe attitudes were around who should make a decision to returning to play after concussion and the safety of attitudes declined as the importance of a rugby match increased. 
Ethnicity consistently influenced knowledge and attitude on all the measures used within the survey. Those identifying as Māori ethnicity scored lower on all knowledge and attitude scales than those identifying as Pakeha ethnicity. Self-rated knowledge of concussion and the number of concussions experienced also had a positive effect on knowledge of concussion. 
There are several educational tools and regulatory documents aimed at minimising the incidence, severity and outcome of concussion in rugby but there is little research guiding how these resources are tailored to their intended audience in the secondary school population. Also, little is known about the gaps in knowledge and understanding of concussion in this population. It is tentatively stated that the findings from this study could be used to inform strategies which are aimed at increasing knowledge and making attitudes safer in secondary school rugby players in New Zealand.

year: 2015