title: Stable isotope and molecular analyses indicate that hybridization with non-native domesticated common carp influence habitat use of native carp

authors: Matsuzaki, Shin-ichiro S.

subjects: non-native species

abstract: Hybridization between native and non-native species has consequences for survival and growth rates of hybrid offspring, but the influences on their functional roles such as habitat use are little studied and poorly understood. The Japanese native common carp Cyprinus carpio coexist and hybridize with non-native domesticated carp in natural Japanese lakes. We have combined stable isotope and molecular information to examine whether habitat use of carp varies depending on the degree of hybridization between native and non-native carp. We sampled 69 carp from Lake Kasumigaura where hybrid swarms between native and non-native carp are advancing, evaluated the degree of hybridization for each individual by genotyping five single nucleotide polymorphism (SNP) markers, and analyzed their carbon and nitrogen stable isotopes. Although we did not find any genetically pure native carp in the lake, the results showed that carp δ13C increased with increasing frequency of non-native alleles but that δ15N did not change. This indicates that non-native carp use the littoral zone more frequently than native carp. This difference in habitat use was supported by a multisource mixing model, showing that the contribution of limnetic primary consumers to the diets of non-native carp was lower than that of individuals with the highest frequency of native alleles. By combining two very different methods, our results thus suggest that multiple-generation hybridization can influence habitat and resource use. Habitat partitioning should be considered when evaluating the genetic impacts of invasive species and races on native species and ecosystem processes.

text: Stable isotope and molecular analyses indicate that hybridization with non-native domesticated common carp influence habitat use of native carp Hybridization between native and non-native species has consequences for survival and growth rates of hybrid offspring, but the influences on their functional roles such as habitat use are little studied and poorly understood. The Japanese native common carp Cyprinus carpio coexist and hybridize with non-native domesticated carp in natural Japanese lakes. We have combined stable isotope and molecular information to examine whether habitat use of carp varies depending on the degree of hybridization between native and non-native carp. We sampled 69 carp from Lake Kasumigaura where hybrid swarms between native and non-native carp are advancing, evaluated the degree of hybridization for each individual by genotyping five single nucleotide polymorphism (SNP) markers, and analyzed their carbon and nitrogen stable isotopes. Although we did not find any genetically pure native carp in the lake, the results showed that carp δ13C increased with increasing frequency of non-native alleles but that δ15N did not change. This indicates that non-native carp use the littoral zone more frequently than native carp. This difference in habitat use was supported by a multisource mixing model, showing that the contribution of limnetic primary consumers to the diets of non-native carp was lower than that of individuals with the highest frequency of native alleles. By combining two very different methods, our results thus suggest that multiple-generation hybridization can influence habitat and resource use. Habitat partitioning should be considered when evaluating the genetic impacts of invasive species and races on native species and ecosystem processes.

year: 2010

title: The post-antibiotic effect of manuka honey on gastrointestinal pathogens

authors: Lin, Shih-Min (Sam)

subjects: biology

abstract: An increasing number of studies have shown that honey has substantial antimicrobial activity [1]. This has mostly been demonstrated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests in which microorganisms are exposed to a constant level of honey for a long period. However, the efficacy of honey taken orally would be greatly affected by dilution in large amounts of body fluids and water from food and drink as well as by a short period of contact with bacterial cells owing to rapid peristalsis in the gastrointestinal tract. We therefore investigated how long it would take manuka honey to eliminate microorganisms and whether or not honey has a post-antibiotic effect (PAE) similar to other common drugs.

text: The post-antibiotic effect of manuka honey on gastrointestinal pathogens An increasing number of studies have shown that honey has substantial antimicrobial activity [1]. This has mostly been demonstrated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests in which microorganisms are exposed to a constant level of honey for a long period. However, the efficacy of honey taken orally would be greatly affected by dilution in large amounts of body fluids and water from food and drink as well as by a short period of contact with bacterial cells owing to rapid peristalsis in the gastrointestinal tract. We therefore investigated how long it would take manuka honey to eliminate microorganisms and whether or not honey has a post-antibiotic effect (PAE) similar to other common drugs.

year: 2010

title: Reha Aperahama: a Ngati Rahiri rangatira

authors: Hart, Philip

abstract: Reha Aperahama had an illustrious whakapapa and was affiliated to several hapu. His father was notable as one of the most loyal rangatira (from the Crown’s perspective) in Hauraki, and Reha followed his lead, probably in part because of the financial rewards he received from selling land to settlers. He tried to maximize his income from this source, spending several years pleading for permission to sell his Te Kawana block (near Te Aroha). After opposing Ngati Haua ambitions to acquire the Aroha block, by 1878 he was willing to encourage road building. 
Reha was regularly before the courts because of his inability or reluctance to pay his debts, occasionally perjuring himself to avoid liability. In his later years he had little money. Despite occasionally being drunk and even violent, he was an important figure in Maori society, with a leadership role in his hapu and in the Mormon church. He was also notable for his marital complications.

text: Reha Aperahama: a Ngati Rahiri rangatira Reha Aperahama had an illustrious whakapapa and was affiliated to several hapu. His father was notable as one of the most loyal rangatira (from the Crown’s perspective) in Hauraki, and Reha followed his lead, probably in part because of the financial rewards he received from selling land to settlers. He tried to maximize his income from this source, spending several years pleading for permission to sell his Te Kawana block (near Te Aroha). After opposing Ngati Haua ambitions to acquire the Aroha block, by 1878 he was willing to encourage road building. 
Reha was regularly before the courts because of his inability or reluctance to pay his debts, occasionally perjuring himself to avoid liability. In his later years he had little money. Despite occasionally being drunk and even violent, he was an important figure in Maori society, with a leadership role in his hapu and in the Mormon church. He was also notable for his marital complications.

year: 2016