Gorges partition diversity within New Zealand flathead Galaxias populations.
J Fish Biol
; 104(4): 950-956, 2024 Apr.
Article
em En
| MEDLINE
| ID: mdl-38018507
ABSTRACT
Understanding the landscape factors governing population connectivity in riverine ecosystems represents an ongoing challenge for freshwater biologists. We used DNA sequence analysis to test the hypothesis that major geomorphological features underpin freshwater-limited fish diversity in a tectonically dynamic region of New Zealand. Phylogeographic analysis of 101 Galaxias depressiceps cytochrome b sequences, incorporating 55 localities from southern New Zealand, revealed 26 haplotypes, with only one shared among rivers. We detect strong hierarchical genetic differentiation both among and within river systems. Genetic structuring is particularly pronounced across the Taieri River system (63 individuals from 35 sites, 18 haplotypes), with 92% of variation partitioned among locations. Distinctive within-river genetic clusters are invariably associated with major subcatchment units, typically isolated by substantial gorges. The anomalous distribution of a single lineage across a major drainage divide is consistent with local, tectonically driven headwater capture. We conclude that major landscape features such as gorges can strongly partition riverine fish diversity and constrain freshwater biodiversity.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ecossistema
/
Osmeriformes
Limite:
Animals
País/Região como assunto:
Oceania
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article