Terrestrial hibernation in the northern cricket frog, Acris crepitans

1999 ◽  
Vol 77 (8) ◽  
pp. 1240-1246 ◽  
Author(s):  
Jason T Irwin ◽  
Jon P Costanzo ◽  
Richard E Lee, Jr.
Keyword(s):  
Habitat Selection ◽  
Laboratory Experiments ◽  
Pond Water ◽  
Field Observations ◽  
Supercooling Point ◽  
Acris Crepitans ◽  
Selection Experiments ◽  
Cricket Frog ◽  
Freeze Tolerant ◽  
Cricket Frogs

We used laboratory experiments and field observations to explore overwintering in the northern cricket frog, Acris crepitans, in southern Ohio and Indiana. Cricket frogs died within 24 h when submerged in simulated pond water that was anoxic or hypoxic, but lived 8-10 days when the water was oxygenated initially. Habitat selection experiments indicated that cricket frogs prefer a soil substrate to water as temperature decreases from 8 to 2°C. These data suggested that cricket frogs hibernate terrestrially. However, unlike sympatric hylids, this species does not tolerate extensive freezing: only 2 of 15 individuals survived freezing in the -0.8 to -2.6°C range (duration 24-96 h). Cricket frogs supercooled when dry (mean supercooling point -5.5°C; range from -4.3 to -6.8°C), but were easily inoculated by external ice at temperatures between -0.5 and -0.8°C. Our data suggested that cricket frogs hibernate terrestrially but are not freeze tolerant, are not fossorial, and are incapable of supercooling in the presence of external ice. Thus we hypothesized that cricket frogs must hibernate in terrestrial sites that adequately protect against freezing. Indeed, midwinter surveys revealed cricket frogs hibernating in crayfish burrows and cracks of the pond bank, where wet soils buffered against extensive freezing of the soil.

168 A NONINVASIVE, TRANSDERMAL ABSORPTION APPROACH FOR EXOGENOUS HORMONE INDUCTION OF SPAWNING IN THE NORTHERN CRICKET FROG, ACRIS CREPITANS: A MODEL FOR SMALL ENDANGERED AMPHIBIANS

2013 ◽  
Vol 25 (1) ◽  
pp. 232 ◽  
Author(s):  
W. E. Snyder ◽  
V. L. Trudeau ◽  
N. M. Loskutoff
Keyword(s):  
Pond Water ◽  
Critically Endangered ◽  
Ex Situ ◽  
Amphibian Conservation ◽  
Dopamine Antagonist ◽  
Exogenous Hormone ◽  
Transdermal Absorption ◽  
Acris Crepitans ◽  
Cricket Frog ◽  
Cricket Frogs

The World Conservation Union (IUCN) currently recognises Eleutherodactylus locustus from Puerto Rico and Plectrohyla acanthodes from Mexico and Guatemala as critically endangered, and they are recommended for ex situ breeding by several amphibian conservation organizations (e.g. AZA, ATAG, RCP, and AARK). Because of their very small and delicate bodies, conventional injectable methods developed for hormonally stimulating spawning in larger frogs and toads are undesirable, because this can result in trauma and injury. Recently, a protocol was developed for inducing spawning in frogs by co-injection of a gonadotropin-releasing hormone agonist (GnRHa) with metoclopramide-HCl (MET), a dopamine antagonist (Amphiplex; Trudeau et al. 2010 Rep. Biol. Endo. 8, 36). The goal of this study, therefore, was to determine the effectiveness of Amphiplex using 3 routes of exogenous treatments: (1) direct IP injection (0.4 µg of GnRHa + 10 µg of MET per gram of body weight), (2) injection into prey (1 µg of GnRHa + 25 µg of MET per insect) before feeding, and (3) a 60-min immersion in 10 mL of pond water containing 0.17 µg of GnRHa + 0.42 µg of MET per microliter. The northern cricket frog (Acris crepitans), a very common local species, was used as a model because it is also small, delicate, and difficult to handle. A total of 110 cricket frogs were caught locally either late or after their normal breeding season, sexed as males or females, and segregated into a control group that was housed similarly ex situ but not exposed to Amphiplex and the 3 Amphiplex experimental groups. The frogs were monitored daily for egg production and behavioural amplexus (potential spermiation). The results are summarised as follows (Table 1): of the frogs exposed to the Amphiplex-supplemented pond water, 84% of 38 females deposited eggs, and 6 pairs were observed in amplexus (indicating spermiation). Approximately 27% of more than 2242 eggs were found to develop cleavage divisions, and tadpoles were first observed in vitro after 4 days. In conclusion, to our knowledge this is the first report indicating that transdermal absorption of a reproductive hormone cocktail (e.g. Amphiplex) may serve in the application of assisted reproductive technology to increase the populations of critically endangered amphibians such as frogs and toads that may be too small or delicate for conventional methods of exogenous hormone treatments that require handling and injections. Table 1.Treated northern cricket frogs

scholarly journals Suction-induced habitat selection in sand bubbler crabs

2019 ◽  
Vol 6 (5) ◽  
pp. 190088 ◽  
Author(s):  
Shinji Sassa ◽  
Soonbo Yang
Keyword(s):  
Habitat Selection ◽  
Laboratory Experiments ◽  
Decapod Crustacean ◽  
Field Observations ◽  
Erosion And Deposition ◽  
Direction Of Movement ◽  
State Changes ◽  
Deposition Processes

We show that a decapod crustacean, the sand bubbler crab (SBC) Scopimera globosa , uses suction, which is the tension of moisture in the sediment, to select habitats at normal times and at the time of disaster events, through a range of controlled laboratory experiments and field observations at various sandflats in Japan. When SBCs are released on fields with no spatial suction gradient, their direction of movement is random. However, the situation clearly changes with increasing suction gradients, in which case the SBCs move to suitable zones for burrowing. Predictions based on suction–burrowing relationships coupled with the knowledge of geophysical state changes induced by suction dynamics are consistent with the observed formation of habitats throughout the seasons. Such suction-induced habitat selection in SBCs manifests itself in a robust way even following sudden events such as typhoons, where erosion and deposition processes distinctly alter the geomorphological profiles, as well as the states of suction, yet consistently yielding habitats at the newly formed, suitable suction environments. Repeated battles were observed in a suitable suction environment over burrows, with the competition rate more than seven times as high as that in a critical suction environment for burrowing.

scholarly journals Hydraulic transmissivity inferred from ice-sheet relaxation following Greenland supraglacial lake drainages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ching-Yao Lai ◽  
Laura A. Stevens ◽  
Danielle L. Chase ◽  
Timothy T. Creyts ◽  
Mark D. Behn ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Ice Sheet ◽  
Drainage System ◽  
Greenland Ice Sheet ◽  
Field Observations ◽  
Surface Uplift ◽  
Drainage Networks ◽  
Order Of Magnitude ◽  
Lake Drainage ◽  
Magnitude Increase

AbstractSurface meltwater reaching the base of the Greenland Ice Sheet transits through drainage networks, modulating the flow of the ice sheet. Dye and gas-tracing studies conducted in the western margin sector of the ice sheet have directly observed drainage efficiency to evolve seasonally along the drainage pathway. However, the local evolution of drainage systems further inland, where ice thicknesses exceed 1000 m, remains largely unknown. Here, we infer drainage system transmissivity based on surface uplift relaxation following rapid lake drainage events. Combining field observations of five lake drainage events with a mathematical model and laboratory experiments, we show that the surface uplift decreases exponentially with time, as the water in the blister formed beneath the drained lake permeates through the subglacial drainage system. This deflation obeys a universal relaxation law with a timescale that reveals hydraulic transmissivity and indicates a two-order-of-magnitude increase in subglacial transmissivity (from 0.8 ± 0.3 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 to 215 ± 90.2 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 ) as the melt season progresses, suggesting significant changes in basal hydrology beneath the lakes driven by seasonal meltwater input.

Planktivory by alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) on microcrustacean zooplankton and dreissenid (Bivalvia: Dreissenidae) veligers in southern Lake Ontario

1995 ◽  
Vol 52 (5) ◽  
pp. 925-935 ◽  
Author(s):  
Edward L. Mills ◽  
Connie Adams ◽  
Robert O'Gorman ◽  
Randall W. Owens ◽  
Edward F. Roseman
Keyword(s):  
Laboratory Experiments ◽  
Lake Ontario ◽  
Osmerus Mordax ◽  
Field Observations ◽  
Alosa Pseudoharengus ◽  
Rainbow Smelt ◽  
Consumption Rates ◽  
South Shore ◽  
Young Of The Year ◽  
Veliger Larvae

The objective of this study was to describe the diet of young-of-the-year and adult alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) in nearshore waters coincident with the colonization of Lake Ontario by Dreissena. Laboratory experiments and field observations indicated that alewife and rainbow smelt consumed dreissenid veligers and that the veligers remained intact and identifiable in the digestive tract for several hours. Dreissenid larvae were found in field-caught alewife and rainbow smelt in August 1992, even though veliger densities were low (<0.1/L). Zooplankton dominated the diet of all fish and veliger larvae were <0.1% of the biomass of prey eaten by these fish. Density of veligers and the distribution of settled dreissenids declined from west to east along the south shore of Lake Ontario. Based on veliger consumption rates we measured and the abundance of veligers and planktivores, we conclude that planktivory by alewife and smelt in the nearshore waters of Lake Ontario did not substantially reduce the number of veligers during 1991–1993. However, our results indicate that if the density of veligers in Lake Ontario decreases, and if planktivores remain abundant, planktivory on veliger populations could be significant.

scholarly journals A sink host allows a specialist herbivore to persist in a seasonal source

2021 ◽  
Vol 288 (1958) ◽  
pp. 20211604
Author(s):  
Alicja Laska ◽  
Sara Magalhães ◽  
Mariusz Lewandowski ◽  
Ewa Puchalska ◽  
Kamila Karpicka-Ignatowska ◽  
...  
Keyword(s):  
Experimental Evolution ◽  
Laboratory Experiments ◽  
Field Observations ◽  
Stepping Stones ◽  
Specialist Herbivore ◽  
Negative Growth Rate ◽  
Evolutionary Rescue ◽  
Main Host ◽  
Negative Growth

In seasonal environments, sinks that are more persistent than sources may serve as temporal stepping stones for specialists. However, this possibility has to our knowledge, not been demonstrated to date, as such environments are thought to select for generalists, and the role of sinks, both in the field and in the laboratory, is difficult to document. Here, we used laboratory experiments to show that herbivorous arthropods associated with seasonally absent main (source) habitats can endure on a suboptimal (sink) host for several generations, albeit with a negative growth rate. Additionally, they dispersed towards this host less often than towards the main host and accepted it less often than the main host. Finally, repeated experimental evolution attempts revealed no adaptation to the suboptimal host. Nevertheless, field observations showed that arthropods are found in suboptimal habitats when the main habitat is unavailable. Together, these results show that evolutionary rescue in the suboptimal habitat is not possible. Instead, the sink habitat functions as a temporal stepping stone, allowing for the persistence of a specialist when the source habitat is gone.

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