Comparative sensitivities of larval stages of the cane toad, Rhinella marina, and the striped marsh frog, Limnodynastes peronii, to atrazine

Variations in larval sensitivities to atrazine were determined in the Australian native striped marsh frog, Limnodynastes peronii, and the introduced cane toad, Rhinella marina. The static acute test design involved six nominal concentrations of atrazine, including control, solvent control, 3, 6, 12, and 24 mg L–1. Gosner stages 22–23 as hatchlings, stages 25–26, 28–29, and 32–33 as premetamorphic, 36–37 as prometamorphic and 40–41 as metamorphic climax stages of cane toads and the first four sets of Gosner stages of striped marsh frogs were exposed to atrazine treatments for 96 h. Results showed that late larval stages were more sensitive than early stages and different premetamorphic stages showed variations in sensitivities in both test species. The striped marsh frog showed a stronger concentration- and stage-dependent response and greater sensitivity to atrazine than the cane toad. In both experimental species, Gosner stages 28–29 showed better concentration-dependent increase in sensitivities to atrazine compared with other larval stages. It can be concluded that inter- and intra-species variations in sensitivities to atrazine may occur in Australian anurans and native species may show greater sensitivity to acute concentrations of atrazine than the introduced cane toad.

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Behaviour and survivorship of a dasyurid predator (Antechinus flavipes) in response to encounters with the toxic and invasive cane toad (Rhinella marina)

Australian Mammalogy ◽

10.1071/am12025 ◽

2013 ◽

Vol 35 (2) ◽

pp. 136 ◽

Cited By ~ 5

Author(s):

Wiebke Kämper ◽

Jonathan K. Webb ◽

Mathew S. Crowther ◽

Matthew J. Greenlees ◽

Richard Shine

Keyword(s):

Native Species ◽

New South ◽

A Priori ◽

Population Declines ◽

Cane Toad ◽

Mammal Species ◽

Rhinella Marina ◽

South Wales ◽

Australian Marsupial ◽

Do So

Australia’s biogeographical isolation has rendered many endemic species vulnerable to invaders. The recent spread of the cane toad (Rhinella marina) has caused serious population declines for some predatory reptile and mammal species. To determine a priori whether or not cane toad poisoning endangers native species, we can test the fates of predators in laboratory trials. We investigated whether an Australian marsupial whose range is increasingly being occupied by cane toads (the yellow-footed antechinus, Antechinus flavipes) is at risk of toad poisoning by testing (1) whether yellow-footed antechinuses approach or attack cane toads and, if so, whether they die as a result; and (2) if they survive, whether they then learn to avoid toads in subsequent encounters. We also investigated the effects of sympatry with toads on the feeding response. In all, 58% of antechinuses from eastern New South Wales approached or attacked a toad (over 4 or 5 opportunities to do so, on successive nights), and none showed ill effects after doing so. Antechinuses that attacked (killed or ingested) toads rapidly learnt to avoid them. Antechinuses from toad-exposed populations ingested more toad flesh, but otherwise reacted in the same ways as did conspecifics from toad-free areas. Hence, the yellow-footed antechinus is unlikely to face population declines via toad poisoning.

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Cane toad ( Rhinella marina ) vitamin A, vitamin E, and carotenoid kinetics

Zoo Biology ◽

10.1002/zoo.21648 ◽

2021 ◽

Author(s):

Tarra Freel ◽

Elizabeth Koutsos ◽

Larry J. Minter ◽

Troy Tollefson ◽

Frank Ridgley ◽

...

Keyword(s):

Vitamin E ◽

Vitamin A ◽

Cane Toad ◽

Rhinella Marina

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Allelopatic effects of Waltheria indica L.: Biocontrol potential in ecological

Research Society and Development ◽

10.33448/rsd-v10i13.21263 ◽

2021 ◽

Vol 10 (13) ◽

pp. e235101321263

Author(s):

Bruno Santos Francisco ◽

Felipe Bueno Dutra ◽

Emerson Viveiros ◽

Raquel Passaretti ◽

Rafael Paranhos Martins ◽

...

Keyword(s):

Ecological Restoration ◽

Aqueous Extract ◽

Lactuca Sativa ◽

Native Species ◽

Initial Step ◽

Cellular Respiration ◽

Aqueous Extracts ◽

Test Species ◽

Leaves And Roots ◽

Urochloa Brizantha

In Brazil, most degraded areas are occupied by exotic and invasive species, which require alternatives for their management. We evaluated the allelopathic effects of Waltheria indica in the laboratory from aqueous extracts of leaves and roots on the germination of the species Lactuca sativa L. (lettuce), Urochloa brizantha (Hochst. ex A.Rich.) RDWebster (brachiaria) and Handroanthus chrysotrichus (Mart. ex DC.) Mattos (yellow Ipe). We collected adult one-year-old Waltheria indica shrubs in ecological restoration areas by direct seeding. We used two treatments with aqueous extracts of leaves and roots and a control without extract, with ten repetitions of 10 seeds per treatment, totaling 600 seeds per test species. Germination and use of tetrazolium assays to evaluate the potential respiratory activity of the roots were used. The aqueous extract of W.indica leaves affected the number of germinated seeds of all test species, while the aqueous extract of roots affected only L. sativa and H. chrysotrichus. There were no significant differences between treatments (leaf and root extracts) in species germination. The aqueous extracts of Waltheria indica leaves and roots affected germination and cellular respiration of the studied species, mainly in Lactuca sativa. The identification of W. indica allelopathic compounds may be an initial step so that in the future new bioherbicides are produced from extracts of this species, or even that its seeds can be sown together with non-sensitive native species, aiming for control of exotic species in ecological restoration projects.

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Changes in urinary testosterone and corticosterone metabolites during short-term confinement with repeated handling in wild male cane toads (Rhinella marina)

Australian Journal of Zoology ◽

10.1071/zo11070 ◽

2011 ◽

Vol 59 (4) ◽

pp. 264 ◽

Cited By ~ 14

Author(s):

Edward J. Narayan ◽

Frank C. Molinia ◽

John F. Cockrem ◽

Jean-Marc Hero

Keyword(s):

Adult Male ◽

Reproductive Effort ◽

Hormone Secretion ◽

Reproductive Hormone ◽

Cane Toad ◽

Short Term ◽

Rhinella Marina ◽

Testosterone Secretion ◽

Metabolite Concentrations ◽

Corticosterone Metabolites

Stressors generally decrease testosterone secretion and inhibit reproduction in animals. Urinary testosterone and corticosterone metabolite concentrations were measured in adult male cane toads (Rhinella marina) at the time of capture from the wild and during 24 h of confinement with repeated handling. Mean urinary testosterone concentrations increased 2 h after capture, were significantly elevated above initial concentrations at 5 h, and then declined. Mean testosterone concentrations remained elevated 24 h after capture. Mean urinary corticosterone concentrations increased after capture, were significantly elevated above initial concentrations at 2 h, and remained elevated thereafter. This is the first report in amphibians of an increase in testosterone excretion after capture from the wild, with previous studies showing either no change or decline in testosterone. This finding may be associated with the mating strategy and maintenance of reproductive effort in the cane toad, a species that shows explosive breeding and agonistic male–male interactions during breeding. The finding that testosterone excretion increases rather than decreases after capture in male cane toads shows that it should not be generally assumed that reproductive hormone secretion will decrease after capture in amphibians.

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Mourning Dove (Zenaida macroura) and Eastern Bluebird (Sialia sialis) Found in Diet of the Non-Native Cane Toad (Rhinella marina) in Florida

Southeastern Naturalist ◽

10.1656/058.020.0408 ◽

2021 ◽

Vol 20 (4) ◽

Author(s):

Melinda J. Schuman ◽

Susan L. Snyder ◽

Copley H. Smoak ◽

Carla J. Dove

Keyword(s):

Mourning Dove ◽

Cane Toad ◽

Zenaida Macroura ◽

Rhinella Marina ◽

Sialia Sialis ◽

Eastern Bluebird

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Non-reproductive male cane toads ( Rhinella marina ) withhold sex-identifying information from their rivals

Biology Letters ◽

10.1098/rsbl.2019.0462 ◽

2019 ◽

Vol 15 (8) ◽

pp. 20190462 ◽

Cited By ~ 2

Author(s):

Crystal Kelehear ◽

Richard Shine

Keyword(s):

Sexual Identity ◽

Standardized Tests ◽

Opportunity Cost ◽

Cane Toad ◽

Rhinella Marina ◽

Secondary Sexual Characteristics ◽

Sexual Characteristics ◽

Reproductive Male ◽

Male Specific ◽

Do So

A male cane toad ( Rhinella marina ) that mistakenly clasps another male (rather than a female) in a sexual embrace (amplexus) can be induced to dismount by a male-specific ‘release call'. Although that sex-identifying system can benefit both males in that interaction, our standardized tests showed that one-third of male cane toads did not emit release calls when grasped. Most of those silent males were small, had small testes relative to body mass, and had poorly developed secondary sexual characteristics. If emitting a release call is costly (e.g. by attracting predators), a non-reproductive male may benefit by remaining silent; other cues (such as skin rugosity) will soon induce the amplexing male to dismount, and the ‘opportunity cost’ to being amplexed (inability to search for and clasp a female) is minimal for non-reproductive males. Hence, male toads may inform other males about their sexual identity only when it is beneficial to do so.

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