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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.

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Related in: MedlinePlus

Life histories of West Pacific freshwater fish communities.Proportion of the freshwater fish community from differing sub-regions of the West Pacific that display an amphidromous life history (solid bars) and are non-diadromous (open bars).
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pone-0026685-g006: Life histories of West Pacific freshwater fish communities.Proportion of the freshwater fish community from differing sub-regions of the West Pacific that display an amphidromous life history (solid bars) and are non-diadromous (open bars).

Mentions: Only one non-diadromous freshwater species, Mogurnda adspersa, was encountered during the survey. All other species were diadromous, with the sub-form amphidromy being the most prevalent life history strategy in CWTS, comprising 60% of the total fauna sampled (Fig. 6). This is high when compared to the proportion of amphidromous species found on adjacent WTS (28%) and WTR (15%), or PNGR (9%). Conversely, such a high level of amphidromy is comparable with WPIS regions (50%). The majority of species observed in CWTS have distributions that extend to Indo-Pacific islands (79%).


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)

Life histories of West Pacific freshwater fish communities.Proportion of the freshwater fish community from differing sub-regions of the West Pacific that display an amphidromous life history (solid bars) and are non-diadromous (open bars).
© Copyright Policy
Related In: Results  -  Collection

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

pone-0026685-g006: Life histories of West Pacific freshwater fish communities.Proportion of the freshwater fish community from differing sub-regions of the West Pacific that display an amphidromous life history (solid bars) and are non-diadromous (open bars).
Mentions: Only one non-diadromous freshwater species, Mogurnda adspersa, was encountered during the survey. All other species were diadromous, with the sub-form amphidromy being the most prevalent life history strategy in CWTS, comprising 60% of the total fauna sampled (Fig. 6). This is high when compared to the proportion of amphidromous species found on adjacent WTS (28%) and WTR (15%), or PNGR (9%). Conversely, such a high level of amphidromy is comparable with WPIS regions (50%). The majority of species observed in CWTS have distributions that extend to Indo-Pacific islands (79%).

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