Natural hybridization between Murray cod, Maccullochella peelii peelii (Mitchell) and trout cod, Maccullochella macquariensis (Cuvier) (Percichthyidae) in the Murray River, Australia

1995 ◽  
Vol 46 (4) ◽  
pp. 729 ◽  
Author(s):  
JW Douglas ◽  
GJ Gooley ◽  
BA Ingram ◽  
ND Murray ◽  
LD Brown
Keyword(s):  
Interspecific Hybrids ◽  
First Generation ◽  
First Record ◽  
Natural Hybridization ◽  
Wild Populations ◽  
Sympatric Populations ◽  
Naturally Occurring ◽  
Murray River ◽  
Management Policies ◽  
Murray Cod

Hybridization is confirmed between two wild, naturally sympatric populations of Murray cod, Maccullochella peelii peelii, and trout cod, M. macquariensis, from the Murray River, Australia. Electrophoretic comparisons of proteins in muscle and liver tissues from trout cod, Murray cod, an artificially produced hybrid of Murray cod and trout cod, and putative wild hybrids from the Murray River indicated that the last group were first-generation interspecific hybrids. This is the first record of hybridization between naturally occumng populations of these two species. Naturally occurring wild populations of both trout cod and Murray cod are nonetheless genetically distinct and there is no evidence of introgression between the species. These findings have some implications for management policies and practices in relation to both species, and these are discussed.

Phenology and Parasitism of Harlequin Bugs, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae), in Southwest Virginia

1998 ◽  
Vol 33 (1) ◽  
pp. 33-39 ◽  
Author(s):  
S. W. Ludwig ◽  
L. T. Kok
Keyword(s):  
First Generation ◽  
First Record ◽  
Early Spring ◽  
Cultivated Plants ◽  
Third Generation ◽  
Subsequent Generation ◽  
Egg Masses ◽  
Naturally Occurring ◽  
Murgantia Histrionica ◽  
Field Plots

Field plots containing broccoli, mustard, and rape were sampled weekly between June and October in 1994 and 1995 to determine parasitism and phenology of the harlequin bug, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae). Naturally-occurring wild turnips also were sampled in early spring 1995 for harlequin bugs before cultivated crops were planted. Weekly samples of harlequin bug adults, egg masses, and nymphs were field collected and returned to the laboratory. They were maintained in the laboratory until emergence to recover parasitoids and to determine the parasitization rates. No adult or nymphal parasitoids were recovered. Two species, Trissolcus murgantiae Ashmead (Hymenoptera: Scelionidae) and Ooencyrtus johnsoni Howard (Hymenoptera: Encyrtidae), were identified as egg parasitoids. The overall parasitization rates for 1994 and 1995 were 8% and 37%, respectively. Trissolcus murgantiae was more common than O. johnsoni and accounted for 87% and 96% of the parasitization, respectively. This is the first record of T. murgantiae in Virginia. The harlequin bugs had two and a partial third generation a year. Overwintered adults oviposited on wild turnips, where the first generation completed development. The subsequent generation migrated to cultivated plants in June and July. The second generation completed development on cultivated crops producing the adults which overwinter.

First record of natural hybridization between pikeperch Sander lucioperca and Volga pikeperch S. volgensis

2010 ◽  
Vol 26 (3) ◽  
pp. 481-484 ◽  
Author(s):  
T. Müller ◽  
J. Taller ◽  
B. Kolics ◽  
B. Kovács ◽  
B. Urbányi ◽  
...  
Keyword(s):  
First Record ◽  
Natural Hybridization ◽  
Sander Lucioperca

Spatial partitioning in the use of structural woody habitat supports the cohabitation of two cod species in a large lowland river

2016 ◽  
Vol 67 (12) ◽  
pp. 1835 ◽  
Author(s):  
J. A. Lieschke ◽  
J. P. Lyon ◽  
P. D. Moloney ◽  
S. J. Nicol
Keyword(s):  
Lowland River ◽  
Specific Interactions ◽  
Negative Consequences ◽  
Catch Per Unit Effort ◽  
Spatial Partitioning ◽  
Murray River ◽  
Eastern Australia ◽  
The Common ◽  
Species Specific ◽  
Murray Cod

Many freshwater fish worldwide have been shown to use Structural Woody Habitat (SWH) for a variety of reasons. The mid reaches of the Murray River, a large lowland river in south-eastern Australia, was surveyed by boat electrofishing, to investigate the use of SWH type (hollows, rootmass and solids), SWH distance to bank (near bank, intermediate to bank and mid-channel) and the interaction between SWH type and distance to bank. The study found that Murray cod catch per unit effort (CPUE) increased in near-bank areas when hollows were a component of the SWH. The CPUE of trout cod was higher when hollows were present. However, the interactions between distance to bank and hollow SWH were complex and dependent on presence or absence of rootmass. The species-specific interactions between SWH microhabitat and distance to bank found within this study has important relevance for stream managers. The common practice of realigning SWH favours Murray cod over trout cod, which could have negative consequences for the endangered trout cod. More broadly, managers may need to consider a balance of SWH type and where it is placed in the river for the species they are targeting when rehabilitating rivers via the introduction of SWH.

Natural Hybridization and Morphometric Relationships Between Three Mallee Eucalypts in the Fitzgerald River National Park, W.A

1978 ◽  
Vol 26 (3) ◽  
pp. 319 ◽  
Author(s):  
SD Hopper ◽  
DJ Coates ◽  
AH Burbidge
Keyword(s):  
Multivariate Analysis ◽  
National Park ◽  
Parental Species ◽  
Natural Hybridization ◽  
Reproductive Parameters ◽  
Sympatric Population ◽  
Sympatric Populations

The suspected occurrence of natural hybridization between Eucalyptus preissiana Schau, and E. Buprestium F. Muell, near West Mount Barren was investigated through a study of morphometric and reproductive parameters in allopatric and sympatric populations of these species. While E. Preissiana and E. buprestium were morphometrically distinct in allopatry, a small number of intermediate individuals occurred in one of the two sympatric populations examined. These intermediates set less fruit per plant than the parental species on average, a fact consistent with the hypothesis that they were hybrids showing partial F2 breakdown. The demonstration that New Holland honeyeaters (Phylidonyris novae-hollandiae) carried pollen of both parental species in a sympatric population was interpreted as further evidence in support of the occurrence of hybridization. The possible hybrid status of E. chrysantha Blakely & Steedman was investigated through determining its morphometric relationships in a multivariate analysis of E. sepulcralis F. Muell., E. Preissiana and E. buprestium. E. chrysantha was intermediate between E. sepulcralis and E. preissiana, and distinguishable from E. preissiana-E. buprestium hybrids in this analysis. The taxonomic and evolutionary implications of the study are discussed.

Experimental pathogenicity of Vibrio parahaemolyticus for the schistosome-bearing snail Biomphalaria glabrata

1980 ◽  
Vol 26 (4) ◽  
pp. 503-506 ◽  
Author(s):  
Hugh W. Ducklow ◽  
Hector M. Tarraza Jr. ◽  
Ralph Mitchell
Keyword(s):  
Puerto Rican ◽  
Vibrio Parahaemolyticus ◽  
Trichloroacetic Acid ◽  
Sublethal Effects ◽  
Lethal Dose ◽  
Biomphalaria Glabrata ◽  
Wild Populations ◽  
Naturally Occurring ◽  
Experimental Pathogenicity ◽  
Significant Mortality

The bacterium Vibrio parahaemolyticus was found to be pathogenic for the schistosome intermediate host Biomphalaria glabrata (Say). When administered topically, a nonenteritis- associated strain of the bacterium had an LD50 (median lethal dose) of 6.8 × 107 cells per snail. A 5% trichloroacetic acid (TCA) extract from V. parahaemolyticus was found to kill B. glabrata. Sublethal effects of V. parahaemolyticus include shell deterioration and increased heart rate. Both albino aquarium populations and naturally occurring Puerto Rican wild populations of B. glabrata are susceptible to V. parahaemolyticus. This bacterium provides a useful model for the study of pathogens and biological control of schistosome vector snails, since it causes significant mortality and is recognized as a pathogen of other invertebrates.

scholarly journals Who’s your mama? Riverine hybridisation of threatened freshwater Trout Cod and Murray Cod

2016 ◽  
Author(s):  
Alan J Couch ◽  
Peter J Unmack ◽  
Fiona J Dyer ◽  
Mark Lintermans
Keyword(s):  
Wild Populations ◽  
Fish Breeding ◽  
Snp Data ◽  
Murray Darling Basin ◽  
In The Wild ◽  
Murray Cod ◽  
First Time ◽  
Hybridization And Introgression

Rates of hybridization and introgression are increasing dramatically worldwide because of translocations, restocking of organisms and habitat modifications (Allendorf et al., 2001) thus determining whether hybridization is beneficial or detrimental for the species involved is commensurately important for conservation. Restocking programs are sometimes criticized because of the genetic consequences of hatchery-bred fish breeding with wild populations. These concerns are important to conservation restocking programs, including Percichthyidae. Two of the better known Australian Percichthyidae are the Murray Cod (Maccullochella peelii) and Trout Cod (Maccullochella macquariensis) which were formerly widespread over the Murray Darling Basin. In much of the Murrumbidgee River Trout Cod and Murray Cod were sympatric until the late 1970s when Trout Cod were extirpated. Here we use genetic SNP data to examine hybridization and introgression between Murray Cod and Trout Cod in the upper Murrumbidgee River and consider implications for restocking programs. For the first time we have confirmed restocked riverine Trout Cod as reproducing in the wild. We detected hybrid Trout Cod-Murray Cod in the Upper Murrumbidgee, recording the first hybrid larvae in the wild. Although hybrid larvae, juveniles and adults have been recorded in hatcheries and impoundments, and hybrid adults have been recorded in rivers previously (Douglas, Gooley & Ingram, 1994a; Douglas et al., 1995) , this is the first time fertile F1 have been recorded in the wild. The F1 backcrosses with Murray cod have also been found to be fertile. All backcrosses noted were with pure Murray Cod. Such introgression has not been recorded previously in these two species, and the imbalance in hybridization direction may have important implications for restocking programs.

scholarly journals Natural hybridization between two butterfly bushes in Tibet: dominance of F1 hybrids promotes strong reproductive isolation

2021 ◽  
Author(s):  
Rongli Liao ◽  
Weibang Sun ◽  
Yongpeng Ma
Keyword(s):  
Morphological Characters ◽  
Natural Hybridization ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Sympatric Populations ◽  
Intergenic Spacers ◽  
Typical Distribution ◽  
Hybridization Origin ◽  
Butterfly Bush ◽  
Disturbed Habitats

Abstract Background: It has been recognized that certain amount of habitat disturbance is a prerequisite for occurrence of natural hybridization, yet we are currently still not aware of any studies exploring hybridization and reproductive barriers to those plants preferably occupying disturbed habitats. Buddleja plants (also called butterfly bush) generally grow in disturbed habitat, and several species with hybrid origin only on basis of morphology evidence have been proposed. Results: In the present study, we test the natural hybridization origin hypothesis of B. × wardii in two sympatric populations of three taxa including B. × wardii and its parents (B. alternifolia and B. crispa) plus 4 referenced parental populations, using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii was likely to be hybrids between B. alternifolia and B. crispa, and moreover, most of the hybrids examined were confirmed to be F1s. This was further supported by morphology as no transgressive characters were detected. B. crispa was found to be the maternal parent in Bahe (BH) population from the cpDNA. While in the Taji (TJ) population was difficult to distinguish the hybridization direction due to the shared haplotypes of cpDNA between B. alternifolia and B. crispa, we still predicted the similar unidirectional hybridization pattern due to results from cross-specific pollination treatments which supported the “SI x SC rule”. Conclusions: Hybrids mainly consisting of F1s can successfully impede gene flow and thus maintain species boundaries of parental species in its typical distribution of Buddleja, i.e. disturbed habitats.

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