scholarly journals Two new cryptic species of the freshwater fish genus Gobiomorphus (Gobiiformes: Gobioidei: Eleotridae) in New Zealand

Author(s):  
Christine E. Thacker ◽  
Daniel L. Geiger ◽  
James J. Shelley
2020 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2009 ◽  
Vol 23 (1) ◽  
pp. 19 ◽  
Author(s):  
Hamish G. Spencer ◽  
Bruce A. Marshall ◽  
Jonathan M. Waters

The seven currently recognised New Zealand species in the gastropod genus Diloma Philippi, 1845 are an important component of New Zealand’s littoral biodiversity across a range of intertidal habitats. A new cryptic species in this genus (Diloma durvillaea, sp. nov.) is described largely on molecular grounds from exposed coasts of the South Island of New Zealand from Lyttelton south, as well as the Auckland Islands. The shell is very similar to D. arida (Finlay, 1926), differing subtly in having stronger spiral ribs and less extensive or no yellow spotting. Phylogenetic analysis of the mitochondrial cytochrome c oxidase I (COI) gene shows these two species are sister-taxa and are more distinct from each other (genetic distance 11.5%) than are the morphologically divergent sister-species D. subrostrata (Gray, 1835) and D. aethiops (Gmelin, 1791) (8.2%), also from New Zealand. The new species is found in a novel habitat for the genus, in the holdfasts and on the blades of the bull kelp, Durvillaea antarctica (Cham.) Har. (Phaeophyta), at the low-tide mark on exposed coasts, whereas D. arida occurs higher up on the shore, as well as in more sheltered situations.


2021 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2021 ◽  
Author(s):  
◽  
Peter Martin

<p>The brown algal genus Lessonia is distributed in the Southern Hemisphere where it can form dominant kelp beds on the exposed rocky shores of New Zealand, South America and Tasmania. Its disjunct distribution within the West Wind Drift contrasts with the view that it is a poor disperser. Apart from studies in Chile, where it is an economically important genus, little is known about Lessonia and in some areas even the number of species is unknown. Using different genetic markers I examined the phylogeny, phylogeography, and the connectivity of populations in Lessonia. Using the literature, species affiliations and nomenclatural problems have been investigated. Combining the sequences of three mitochondrial, one chloroplast and two nuclear markers, a supermatrix approach was used to investigate the phylogenetic relationship and the timing of speciation for all known Lessonia species. The Australasian Lessonia species form a clade within a paraphyletic grouping of South American species. Radiation in Lessonia occurred about 5 Mya at the beginning of the Pliocene and rapid radiation took place in Australasia 3.5 Mya. The data also revealed cryptic species within a L. variegata species complex. Further analysis within the Australasian clade, using mitochondrial (atp8-sp) and chloroplast (rbc-sp) markers and wider sampling (469 individuals from 57 sample sites) supported four cryptic species and revealed localized distribution for all Australasian lineages. Genetic breaks between Lessonia lineages corresponded well to known biogeographic regions and could be correlated to the geographic structure of New Zealand at the end of the Pliocene. The Cook Strait region was analysed more closely with newly developed microsatellite markers to test the influence of geographic breaks (Cook Strait and Palliser Bay) on the connectivity of populations. The results suggested that connectivity depends on the width of unsuitable habitat, and within inner Cook Strait it is facilitated by sometimes strong tidal flows that create turbulences and unique current patterns. The results implied that rafting is an important mean of dispersal. The study of the early literature on Lessonia supported the new lectotypification of L. flavicans but revealed that L. frutescens and possibly L. ovata (supported by images of rediscovered herbarium material) are synonymous to L. searlesiana and as the older epithets they should have priority. Suggestions have been made for the lectotypification of L. fuscescens and L. ovata. In general Lessonia shows non-overlapping distribution in Australasia but overlapping distribution in South America. Despite being a poor disperser, indicated by fine scale genetic structure, Lessonia is also able to connect populations over wide areas of unsuitable habitats.</p>


2018 ◽  
Author(s):  
Adam D Canning

Biomonitoring is a common method to monitor environmental change in river ecosystems, a key advantage of biomonitoring over snap-shot physicochemical monitoring is that it provides a more stable, long-term. insight into change that is also effects-based. In New Zealand, the main biomonitoring method is a macroinvertebrate sensitivity scoring index, with little established methods available for biomonitoring of fish. This study models the contemporary distribution of common freshwater fish and then uses those models to predict freshwater fish assemblages for each river reach under reference conditions. Comparison of current fish assemblages with those predicted in reference conditions (as observed/expected ratios) may provide a suitable option for freshwater fish biomonitoring. Most of the fish communities throughout the central North Island and lower reaches show substantial deviation from the modelled reference community. Most of this deviation is explained by nutrient enrichment, followed by downstream barriers (i.e., dams) and loss of riparian vegetation. The presence of modelled introduced species had relatively little on the presence of the modelled native fish. The maps of observed/expected fish assemblage may provide a rapid way to identify potential restoration sites.


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