Limits...
Amphidromy links a newly documented fish community of continental Australian streams, to oceanic islands of the west Pacific.

Thuesen PA, Ebner BC, Larson H, Keith P, Silcock RM, Prince J, Russell DJ - PLoS ONE (2011)

Bottom Line: First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers.Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics.The evolutionary and conservation significance of this newly discovered Australian fauna requires clarification in the context of the wider amphidromous fish community of the Pacific.

View Article: PubMed Central - PubMed

Affiliation: School of Marine and Tropical Biology, James Cook University, Cairns, Queensland, Australia. paul.thuesen@gmail.com

ABSTRACT

Background: Indo-Pacific high island streams experience extreme hydrological variation, and are characterised by freshwater fish species with an amphidromous life history. Amphidromy is a likely adaptation for colonisation of island streams following stochastic events that lead to local extirpation. In the Wet Tropics of north-eastern Australia, steep coastal mountain streams share similar physical characteristics to island systems. These streams are poorly surveyed, but may provide suitable habitat for amphidromous species. However, due to their ephemeral nature, common non-diadromous freshwater species of continental Australia are unlikely to persist. Consequently, we hypothesise that coastal Wet Tropics streams are faunally more similar, to distant Pacific island communities, than to nearby faunas of large continental rivers.

Methods/principal findings: Surveys of coastal Wet Tropics streams recorded 26 species, 10 of which are first records for Australia, with three species undescribed. This fish community is unique in an Australian context in that it contains mostly amphidromous species, including sicydiine gobies of the genera Sicyopterus, Sicyopus, Smilosicyopus and Stiphodon. Species presence/absence data of coastal Wet Tropics streams were compared to both Wet Tropics river networks and Pacific island faunas. ANOSIM indicated the fish fauna of north-eastern Australian coastal streams were more similar to distant Pacific islands (R = 0.76), than to nearby continental rivers (R = 0.98).

Main conclusions/significance: Coastal Wet Tropics streams are faunally more similar to distant Pacific islands (79% of species shared), than to nearby continental fauna due to two factors. First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers. Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics. The evolutionary and conservation significance of this newly discovered Australian fauna requires clarification in the context of the wider amphidromous fish community of the Pacific.

Show MeSH

Related in: MedlinePlus

Phenogram of West Pacific freshwater fish communities.Phenogram derived from a Bray-Curtis similarity matrix of presence/absence data of freshwater fish fauna from sub-regions of the West Pacific (Key: PNGR  =  Papua New Guinea rivers, WPIS  =  West Pacific island streams, WTR  =  Wet Tropics rivers, WTS  =  Wet Tropics streams, CWTS  =  coastal Wet Tropics streams).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3198781&req=5

pone-0026685-g004: Phenogram of West Pacific freshwater fish communities.Phenogram derived from a Bray-Curtis similarity matrix of presence/absence data of freshwater fish fauna from sub-regions of the West Pacific (Key: PNGR  =  Papua New Guinea rivers, WPIS  =  West Pacific island streams, WTR  =  Wet Tropics rivers, WTS  =  Wet Tropics streams, CWTS  =  coastal Wet Tropics streams).

Mentions: A cluster analysis of the Bray-Curtis similarity matrix data from all sites indicated the grouping of three major clusters: 1) PNGR 2) WTR and WTS 3) CWTS and WPIS (Fig. 4). Within cluster 2), WTR and WTS formed two separate sub-clusters, respectively. Sites within cluster 3) did not conform strictly to a priori designations.


Amphidromy links a newly documented fish community of continental Australian streams, to oceanic islands of the west Pacific.

Thuesen PA, Ebner BC, Larson H, Keith P, Silcock RM, Prince J, Russell DJ - PLoS ONE (2011)

Phenogram of West Pacific freshwater fish communities.Phenogram derived from a Bray-Curtis similarity matrix of presence/absence data of freshwater fish fauna from sub-regions of the West Pacific (Key: PNGR  =  Papua New Guinea rivers, WPIS  =  West Pacific island streams, WTR  =  Wet Tropics rivers, WTS  =  Wet Tropics streams, CWTS  =  coastal Wet Tropics streams).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198781&req=5

pone-0026685-g004: Phenogram of West Pacific freshwater fish communities.Phenogram derived from a Bray-Curtis similarity matrix of presence/absence data of freshwater fish fauna from sub-regions of the West Pacific (Key: PNGR  =  Papua New Guinea rivers, WPIS  =  West Pacific island streams, WTR  =  Wet Tropics rivers, WTS  =  Wet Tropics streams, CWTS  =  coastal Wet Tropics streams).
Mentions: A cluster analysis of the Bray-Curtis similarity matrix data from all sites indicated the grouping of three major clusters: 1) PNGR 2) WTR and WTS 3) CWTS and WPIS (Fig. 4). Within cluster 2), WTR and WTS formed two separate sub-clusters, respectively. Sites within cluster 3) did not conform strictly to a priori designations.

Bottom Line: First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers.Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics.The evolutionary and conservation significance of this newly discovered Australian fauna requires clarification in the context of the wider amphidromous fish community of the Pacific.

View Article: PubMed Central - PubMed

Affiliation: School of Marine and Tropical Biology, James Cook University, Cairns, Queensland, Australia. paul.thuesen@gmail.com

ABSTRACT

Background: Indo-Pacific high island streams experience extreme hydrological variation, and are characterised by freshwater fish species with an amphidromous life history. Amphidromy is a likely adaptation for colonisation of island streams following stochastic events that lead to local extirpation. In the Wet Tropics of north-eastern Australia, steep coastal mountain streams share similar physical characteristics to island systems. These streams are poorly surveyed, but may provide suitable habitat for amphidromous species. However, due to their ephemeral nature, common non-diadromous freshwater species of continental Australia are unlikely to persist. Consequently, we hypothesise that coastal Wet Tropics streams are faunally more similar, to distant Pacific island communities, than to nearby faunas of large continental rivers.

Methods/principal findings: Surveys of coastal Wet Tropics streams recorded 26 species, 10 of which are first records for Australia, with three species undescribed. This fish community is unique in an Australian context in that it contains mostly amphidromous species, including sicydiine gobies of the genera Sicyopterus, Sicyopus, Smilosicyopus and Stiphodon. Species presence/absence data of coastal Wet Tropics streams were compared to both Wet Tropics river networks and Pacific island faunas. ANOSIM indicated the fish fauna of north-eastern Australian coastal streams were more similar to distant Pacific islands (R = 0.76), than to nearby continental rivers (R = 0.98).

Main conclusions/significance: Coastal Wet Tropics streams are faunally more similar to distant Pacific islands (79% of species shared), than to nearby continental fauna due to two factors. First, coastal Wet Tropics streams lack many non-diadromous freshwater fish which are common in nearby large rivers. Second, many amphidromous species found in coastal Wet Tropics streams and Indo-Pacific islands remain absent from large rivers of the Wet Tropics. The evolutionary and conservation significance of this newly discovered Australian fauna requires clarification in the context of the wider amphidromous fish community of the Pacific.

Show MeSH
Related in: MedlinePlus