Edible Frog Research Articles

Discrimination of group numerousness under predation risk in anuran tadpoles.

For social animals, group size discrimination may play a major role in setting the trade-off between the costs and benefits of membership. Several anuran tadpoles show different degrees of social aggregation when exposed to the risk of predation. Despite the importance of aggregative behaviour as an anti-predatory response, the mechanism underlying tadpole choice of the group to join to has not been sufficiently investigated. To establish whether visual cues provide sufficient information to enable tadpoles to choose between aggregations differing in size, we explored the abilities of the larvae of two anuran species (green toad Bufotes balearicus and edible frog Pelophylax esculentus) to discriminate among four numerical combinations of conspecific tadpoles (1 vs. 4, 3 vs. 4, 4 vs. 6 and 4 vs. 8), either in the presence or absence of predatory cues. Our results suggest that in anuran larvae the capacity to discriminate between quantities is limited to small numbers (1 vs. 4 for B. balearicus and both 1 vs. 4 and 3 vs. 4 for P. esculentus). Predator-exposed toad tadpoles stayed longer close to the larger group, supporting aggregation as a major anti-predator behaviour in bufonids, while frog tadpoles showed a preference for the smaller groups, though in predator-free trials only, probably associated with lower intra-specific competition.

An evaluation of intestinal parasites in edible frogs (<i>Hoplobatracus</i> spp) sold for consumption in Zaria, Kaduna State, Nigeria

To determine the presence of eggs, oocysts and larvae of intestinal parasites in edible frogs (Hoplobatrachus species) sold for human consumption in Hanwa Zaria, Kaduna State, Northwestern Nigeria. Gastrointestinal tract (GIT) samples of edible frogs (n = 225) were collected from the frog market (FM) at Hanwa, Zaria. The samples were analysed for parasites eggs, oocysts and larvae using zinc sulphate-sucrose floatation method of specific gravity 1.21, sedimentation tests followed by microscopy. Parasitic eggs, larvae, and oocyst were found in 54.7% of the total gastrointestinal tract samples using floatation technique while, eggs were found in 40 (17.8%) of the samples using sedimentation technique. The overall prevalence of the parasitic oocyst, eggs or larva using the simple floatation and sedimentation techniques techniques in the examination of the frog was 63.1% (142/225). The presence of parasites in both the male and female frogs were 92 (75.4%) and 50 (48.5%), respectively, there was statistically significant association between gender and parasite prevalence, P = 0.0001. There was no significant association between original location of frogs and prevalence of parasites, but there was statistically significant association between gender and parasite prevalence, p = 0.525. Coccidia oocysts mean counts were highest (8.11 ± 0.423). People should be educated on how to prevent possible zoonotic transmission to humans during capture, slaughter, processing and/or consumption of raw or improperly cooked frogs.Keywords: Frog, Hoplobatrachus spp, eggs, oocysts, larvae, Zaria

Evaluation of three artificial diets in the culture of tropical edible frog Hoplobatrachus occipitalis (G\xfcnther, 1858) from tadpole stage to full metamorphosis

BackgroundThe consumption of edible frogs caught mainly from the wild is on the rise and their population declining. A challenge to frog farming is the acceptability of artificial diets by frogs. Three artificial diets for the culture of a tropical edible frog Hoplobatrachus occipitalis from tadpole stage to full metamorphosis were evaluated. One hundred eighty Hoplobatrachus occipitalis tadpoles (average length and weight of 5.8 cm ± 0.1 and 1.90+ g ± 0.1) were distributed into three experimental tanks with 60-L water capacity each, renewed through a flow-through system. The tadpoles were fed twice daily at 10% of body mass for 112 days with duckweed, pawpaw leaf, and Coppens fish feed. Water quality parameters and proximate composition of the feeds were determined.ResultsTadpoles fed with duckweed produced the highest percentage weight gained, specific growth rate, feed intake, and efficient food conversion, with mortality of 10%, survival of 90%, and metamorphosis rate of 100%. This was followed by tadpoles fed with pawpaw leaf and those fed with fish feed. Mortality in these two groups was 15%, survival 85%, and metamorphosis rate 98%. Water quality in the tanks was within the ranges optimal for the growth and survival of the tadpoles. The highest growth percentage recorded in tadpoles fed duckweed was due to the high percentage of crude protein in the feed, which was highly digestible and absorbable by the tadpoles. The duckweed suits the herbivorous feeding of the tadpoles which converted the feed to high biomass. A similar trend was observed for pawpaw leaf, and its growth performance as compared to duckweed was due to its low protein content. The lowest growth performance showed in tadpoles fed with Coppens feed in spite of its very high crude protein was due to the lower intake of the feed resulting in high FCR, ineffective absorbance, and utilization of the protein in the feed on the account of herbivorous feeding of the tadpoles. Size, pellet form, floating time, and odor of the feed were other factors responsible for the lower growth performance.ConclusionDuckweed is a good artificial diet for the breeding of Hoplobatrachus occipitalis due to its high protein content and acceptability by the species.

Water quality considerations for the culture of tropical edible frog (Hoplobatrachus occipitalis) from tadpole stage to full metamorphosis

Water quality considerations for the culture of tropical edible frog (Hoplobatrachus occipitalis) from tadpole stage to full metamorphosis

Spermatological characteristics of the family Glypthelminthidae (Digenea, Plagiorchioidea) inferred from the ultrastructural study of Glypthelmins staffordi Tubangui, 1928.

The present study describes the ultrastructural organization of the mature spermatozoon of the digenean Glypthelmins staffordi (Glypthelminthidae) by means of transmission electron microscopy. Live digeneans were collected from the Chinese edible frog (Hoplobatrachus rugulosus) in Udon Thani Province (Thailand). The ultrastructural study reveals that the mature spermatozoon of G. staffordi is a filiform cell, which is tapered at both extremities. It exhibits the Bakhoum et al.'s type IV of spermatozoon of digeneans characterized by the 9+'1' axonemes of trepaxonematan Platyhelminthes, the presence of the association "external ornamentation-cortical microtubules", the external ornamentation located in the posterior part of the anterior region, the arrangement of parallel cortical microtubules in two bundles and with its maximum number located in the anterior part of the sperm cell, and the presence of two mitochondria. Other characteristics are the presence of spine-like bodies, a posterior extremity containing only the nucleus, and the presence of a large amount of glycogen granules. Results of the present study are particularly compared with the existing data in other families of the Plagiorchioidea, namely the Brachycoeliidae, the Haematoloechidae, the Omphalometridae and the Plagiorchiidae.

Occurrence of Salmonella and Shigella in edible frogs (<i>Hoplobatrachus spp</i>) from Hanwa Frog market Zaria, Nigeria

Frogs have been associated with bacterial infection among those who handle them resulting in symptoms such as diarrhoea, abdominal cramps, fever and vomiting. Frogs are a rich source of proteins and they are considered a delicacy by some in Nigeria. Considering the high demand for edible frogs, it is important to determine the occurrence of Salmonella and Shigella organisms from edible frogs (Hoplobatrachus spp). Edible frogs (n=202) were collected from February to July, 2016, from the Hanwa frog market, Zaria, Kaduna State. The intestinal contents of each sampled frog were scraped into the selenite broth bottles and cultured on Deoxycholate Citrate Agar for enrichment and isolation respectively. Biochemical test and sugar fermentation tests were carried out on the suspected isolates. Overall, twenty seven 27(13.37%) of the processed samples were suggestive of Shigella, while 22(10.9%) were suspect Salmonella organisms. There was no significant association between sex of the frogs and the isolation of Shigella and Salmonella organisms, despite the high occurrence of Shigella organism (14.17%) in the males. Source wise the occurrence of Salmonella in frogs was high in Tudun Wada (20%), while Katsina (8.5%) had the least. There was also no association between source and Shigella organisms. Frogs within the weight range of 175-224g had the highest occurrence rate for Shigella isolation, while frogs of 73-125g weight range had the highest occurrence rate for Salmonella isolation. This study shows the presence of Shigella and Salmonella organisms in the intestinal contents of frogs. Therefore the unhygienic and unsanitary environment, handling and processing of frogs is of great public health concern and as such measures are to be put together to ensure safety and wholesomeness of the frog meat been sold for human consumption.Keywords: Edible, Frog, Safety, Salmonella , Shigella, Zaria

Odour recognition learning of multiple predators by amphibian larvae

Many aquatic animals learn to recognize novel predators when they simultaneously perceive the odours of these novel threats paired with alarm cues released by injured conspecifics. Since the odours of several organisms may be present simultaneously in the environment during this process, selection is expected to favour learning mechanisms that allow prey to respond independently to the odour of each species in a mixture of odours. We tested this hypothesis by exposing tadpoles of the edible frog, Pelophylax esculentus, to injured conspecific cues paired with either the odour of two fish species (experiment 1) or one fish and one crayfish species (experiment 2). We subsequently tested the ability of tadpoles to respond to each odour separately. We found clear evidence that tadpoles learned to recognize the odour of individual species in the mixture and that the response to each odour of a mixture was equally strong. However, the learned response was weaker overall in tadpoles conditioned with the mixture of fish and crayfish compared to those with the two fish species. Our study reveals that tadpoles can adaptively handle the presence of multiple predator odours in their environment during conditioned learning, but highlights some constraints that may due to the diversity of predators in the mix.

The programmed DNA elimination and formation of micronuclei in germ line cells of the natural hybridogenetic water frog Pelophylax esculentus

DNA elimination is a radical form of gene silencing and occurs both in somatic and germ cells. The programmed DNA elimination occurs during gametogenesis in interspecies hybrids that reproduce by hybridogenesis (stick insects, fishes, and amphibians) and concerns removal of whole genomes of one of the parental species and production of clonal gametes propagating the genome of the other species. The cellular mechanisms differ considerably in hybridogenetic insects and fishes but remains unknown in edible frogs Pelophylax esculentus, natural hybrids between Pelophylax lessonae and Pelophylax ridibundus. Here we report DNA elimination mechanism in early developing gonads of diploid and triploid hybrid frogs, studied by TEM, immunofluorescence, and cytochemistry. In gonocytes of both sexes (primary oogonia and prespermatogonia), micronuclei emerge as detached nuclear buds formed during interphase. We found depletion of nuclear pore complexes in micronuclear membrane and chromatin inactivation via heterochromatinization followed by degradation of micronuclei by autophagy. Micronuclei formation does not lead to apoptotic cell death showing that genome elimination is a physiological process. Chromatin elimination via micronuclei in P. esculentus is unique among hybridogenetic animals and contributes to broadening the knowledge about reproductive modes in animals.

Do Bufonids Employ Different Anti-Predator Behaviors Than Ranids? Comparison among Three European Anurans

European anurans are prey for a variety of predators, against which they have evolved a range of defense behaviors. We investigated defensive behaviors of three European anurans: the Common Toad (Bufo bufo), the Common Frog (Rana temporaria), and the Edible Frog (Pelophylax esculentus) during interactions with a predator (hedgehog) and a control stimulus (rabbit). We hypothesized that (H1) due to small capacity to flee quickly from a predator, B. bufo has evolved a more diverse repertoire of behavioral defenses than the ranids, R. temporaria and P. esculentus. We also hypothesized that (H2) B. bufo can minimize the secretion of metabolically costly poison through behavioral control. According to our predictions, the repertoire of defensive behaviors was more complex in B. bufo than in the ranids. Also, the number of threatening behaviors was higher in toads than in both frog species. Fleeing was the most common response employed by all tested anurans. We report a new anti-predator behavior in the Common Toad: head hitting. As B. bufo released the poison only after squeezing of parotoid macroglands by the predator, we conclude that the Common Toad can minimize poison release through behavioral control. Our data suggest that length of hind-legs and, related to this, mode of locomotion (jumping vs. hopping) can affect anti-predator behavior in anurans.

Genetic diversity in population systems of green frogs (Pelophylax esculentus complex) in waterbodies of Western Ukraine

The results of the analysis of the genetic structure in population systems of green frogs on the territory of Lviv and Volyn regions are presented. The material was collected in 2011–2012 in water bodies representing three nature regions of Ukraine – Forecarpathians, Roztochia, and Western Polissia. Three taxonomic groups of green frogs were in a focus of the study: Marsh frog – Pelophylax ridibundus (Pallas, 1771), Pool frog – Pelophylax lessonae (Camerano, 1882) and their hybrid – Edible frog – Pelophylax esculentus (Linnaeus, 1758). DNA was extracted from 91 individuals and analyzed using of 10 pairs of primers: Rrid059, Rrid082, Rrid171, Res5, Res14, Res16, Res22, RlCA1b5, RlCA18, RlCA19. A majority of those are highly polymorphic and diagnostic for species identification. During the analysis, we used programs based on principles of Bayesian statistics and Monte-Carlo Markov Chain algorithms: Structure, BAPS, and NewHybrids. Linkage groups were searched using the GenePop software, and hidden null-alleles were detected using Micro-Checker program. For the first time, in the studied area the genetic structure of populations and population systems were described. After the analysis of genetic diversity of frogs sampled from the Pelophylax ridibundus population and from hemiclonal population systems of mixed R-E-L type, we found that the smallest genetic diversity is observed in the population of Marsh frog from the Nyzhankovychi area (Forecarpathians). More diverse are hemiclonal population systems of green frogs sampled in water bodies of “Cholgynskyi” ornithological reserve (Ukrainian Roztochia) and Shatsk National Nature Park (Western Polissia). Also, for the first time, the hybrid composition of studied localities is described. Hybrids of the first generation (F1) and backcrosses were detected in water bodies of Shatsk National Nature Park and ornithological reserve “Cholgynskyi”.

Quality Characteristics of Jook Prepared with Edible Frog (Rana dybowskii) Powder

Quality Characteristics of Jook Prepared with Edible Frog (Rana dybowskii) Powder

Identification and target-modifications of temporin-PE: A novel antimicrobial peptide in the defensive skin secretions of the edible frog, Pelophylax kl. esculentus

A potent natural antimicrobial peptide named temporin-PE was identified and encoded from the skin secretions of Pelophylax kl. esculentus via “shotgun” cloning and LC-MS/MS fragmentation analysis. Target-modifications were carried out to further enhance the antimicrobial and anti-proliferative bioactivities, whilst decreasing the hemolytic effect. A range of bioassays demonstrated that replacing a proline with a tyrosine residue resulted in a loss of the bioactivity against Gram-negative bacteria, but dramatically improved the hemolytic and anti-proliferative activity, indicating the FLP- motif influences the hemolytic activity of temporins. Moreover, the coupling of TAT to the peptide dramatically improved its antimicrobial activity, indicating coupling TAT to these peptides could be considered as a potential tool to improve their antimicrobial activity. Overall, we have shown that targeted modifications of this natural antimicrobial peptide can adjust its bioactivities to help its development as an antibiotic or anti-proliferative agent.

Osmoregulation of pre- and prometamorphic Chinese edible frogs (Hoplobatrachus rugulosus) raised in brackish water relies on body Na+and Cl−concentrations, but not urea production

Aquaculture ResearchVolume 49, Issue 2 p. 1122-1126 SHORT COMMUNICATION Osmoregulation of pre- and prometamorphic Chinese edible frogs (Hoplobatrachus rugulosus) raised in brackish water relies on body Na+ and Cl− concentrations, but not urea production La-iad Nakkrasae, Corresponding Author La-iad Nakkrasae laiana@kku.ac.th orcid.org/0000-0002-9729-3959 Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand Correspondence La-iad Nakkrasae, Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand. Email: laiana@kku.ac.thSearch for more papers by this authorVarin Jaisin, Varin Jaisin Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, ThailandSearch for more papers by this authorNarattaphol Charoenphandhu, Narattaphol Charoenphandhu Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, ThailandSearch for more papers by this author La-iad Nakkrasae, Corresponding Author La-iad Nakkrasae laiana@kku.ac.th orcid.org/0000-0002-9729-3959 Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand Correspondence La-iad Nakkrasae, Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand. Email: laiana@kku.ac.thSearch for more papers by this authorVarin Jaisin, Varin Jaisin Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen, ThailandSearch for more papers by this authorNarattaphol Charoenphandhu, Narattaphol Charoenphandhu Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok, Thailand Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, ThailandSearch for more papers by this author First published: 17 October 2017 https://doi.org/10.1111/are.13534Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume49, Issue2February 2018Pages 1122-1126 RelatedInformation

Genomic Sequencing of Ranaviruses Isolated from Edible Frogs (Pelophylax esculentus).

ABSTRACTRanaviruses were isolated from wild edible frogs (Pelophylax esculentus) during epizootics in Denmark and Italy. Phylogenomic analyses revealed that these isolates are closely related and belong to a clade of ranaviruses that includes the Andrias davidianus ranavirus (ADRV), common midwife toad ranavirus (CMTV), Testudo hermanni ranavirus (THRV), and pike-perch iridovirus (PPIV).

Occurrence of Cryptosporidium oocysts in edible frogs (Rana species) sold for human consumption in Hanwa frog market, Zaria, Kaduna State, Nigeria

Occurrence of Cryptosporidium oocysts in edible frogs (Rana species) sold for human consumption in Hanwa frog market, Zaria, Kaduna State, Nigeria

Multi-locus sequence typing of Laribacter hongkongensis isolates from freshwater animals, environment and diarrhea patients in southern China

Laribacter hongkongensis is a novel emerging bacterium associated with gastroenteritis and invasive bacteremic infections. Freshwater fish and edible frogs have been identified as major reservoirs of L. hongkongensis. Currently one of the main challenges in L. hongkongensis research is to identify their sources and possible transmission routes. The aim of this study was to determine the genetic diversity and relatedness of these L. hongkongensis isolates to their hosts in the hope of shedding light on these issues. In this study, multi-locus sequence typing (MLST) was used to determine the genetic characteristics of 114 L. hongkongensis strains, including 113 isolated from humans, fish, frogs, Amazonian snails and water sample in Guangzhou and Jiangmen, Southern China, and one reference isolate HZ242, recovered from a diarrhea patient in Hangzhou. The relationships among the STs and the relatedness among the isolates were assessed by phylogenetic and eBURST analysis. A total of 72 different sequence types (STs) from 114 isolates of L. hongkongensis were identified by MLST analysis, and ST99-ST161were novel. Significant difference of the prevalence of different STs between fish isolates (41.8%, 23/55) and frog isolates (82.4%, 42/51) was revealed (p=0.000). The most frequent ST (ST45) was identified 28 times and only found in fish isolates. In addition, 10 groups were identified by eBURST in this study. Combined the MLST data from Hong Kong and the present study, there were eight eBRUST lineages (group A-H) included the isolates (49.2%, 128/260) from either numerous hosts or multiple geographic origins, which contained 33.1% (53/160) of all the STs. Group A (n=57, STs=20) consisted exclusively of isolates from fish and 92.9% (39/42) of isolates in group B (n=42, STs=16) were only from fish. Group C-F (n=22, STs=14) were found to be associated with human, apart from other hosts. In this study, extensive genetic heterogeneity among the L. hongkongensis isolates from various hosts was observed. Specifically, there is higher genetic diversity of L. hongkongensis isolates of frog-origin than those of fish-origin. This study indicated some isolates exhibited a preference for specific hosts or geographic areas. ST45 was revealed to be the most frequent ST, which was only found in the fish isolates in Southern China, but might be irrelative to human infection. This MLST study further revealed that frog was likely to be another major source for human infection with L. hongkongensis apart from fish.

An investigation of sudden death in farmed infantSiamesecrocodiles during winter and spring in Hainan, China

Sudden deaths without any specific clinical sign occurred among one year old young ones on Siamese crocodile (Crocodylus siamensis) farms in Hainan province, China, during winter and spring in 2012 - 2013. The autopsy showed that the internal organs seemed normal except full of clear ascites in abdominal cavity. There were total six bacterial species isolated, Edwardsiella tarda, Proteus penneri, Proteus vulgaris, Enterobacter asburiae, Citrobacter freundii and Micrococcus luteus from either the heart bloods or the spleens and livers. The virulence of isolated strains was tested by intraperitoneal inoculation in female Chinese edible frogs (Rana rugulosa or Hoplobatrachus rugulosus). The six-day mortality revealed that E. tarda was the most pathogenic, whereas P. penneri and E. asburiae exhibited no infection at all, and the rest demonstrated similar inconspicuous toxicity. All these findings suggest that E. tarda would be the principal suspect causing death of Siamese crocodile. The sensitivities of the E. tarda isolates were tested against 20 kinds of antimicrobial drugs. The results showed that ceftazidime, norfloxacin and amikacin were highly sensitive to the isolates of E.tarda.

Phenes of water frogs (Pelophylax) as the indicators of water bodies’ contamination in Pre-Carpathians, Roztochia, LESSER and Western Polissia

The results of phenotypic variability of water frogs ( Pelophylax ) analysis depending on internal and external influence factors are presented. 345 individuals of three species (Marsh Frog, Pool Frog and Edible Frog) were taken for the analysis from water bodies of different level of anthropogenic influence. The hydrochemical composition of water from the investigated aquatic ecosystems was analyzed, and the classification of water bodies after their water quality was done. The expression rates of nine phenotypes depending on the species of frog, its age stage and water quality class were established. It was found out that all the analyzed phenes show a significant dependence on the habitat conditions. The expression rates of middorsal stripe, as well as the coloration of femur and tibia depend mostly on water bodies’ contamination level. The increasing level of chemical contamination changes the ratios of alternative variants of middorsal stripe, and coloration of femur and tibia. New variants in coloration of femur and tibia that have never been described were noticed. Pelophylax individuals from the most contaminated water bodies (Cholgyni, Perekalky and Zhovtantsi) showed the highest variability by the analyzed phenes.

English

The Bullfrog Lithobates catesbeianus is a species of economic important edible frog and often chosen as experimental animal model. Although, some studies in the literatures have reported the parameters of hematology and serum biochemistry in several Rana species, a comprehensive profile of hematology and biochemistry in farmed bullfrogs was very limited, especially during the hibernating period. 140 apparently healthy farmed bullfrogs (70 males and 70 females) were used during the active and hibernating periods to determine the hematology and serum biochemistry parameters including morphometry of erythrocytes, PCV, HGB, MCV, MCH, MCHC, RBC count, WBC count, differential leukocyte count, glucose (Glu), triglycerides (TG), cholesterol (Cho), blood urea nitrogen (Bun), uric acid (UA), creatine (Cre), total protein (TP), albumin (Alb), globulin (Glo), γ-glutam (GGT), total bilirubin (TB), alkaline phosphatase (Alp), a-amylase (Amy), CK, AST, ALT, LDH, K, Na, Cl and nCa (that is, the ionized calcium level when pH=7.4). Differences between sexes showed that male bullfrogs possessed a statistically higher LDH activity level, and statistically lower levels of Cre, Na and Ca concentrations. Additionally, it was noted that bullfrogs during the active period had significantly lower values for HGB, PCV, MCV, ALT, Glo, Bun, Na, Cl and surface areas and volumes of RBCs and their nuclei, and significantly higher values for WBCs counts and Cre than the hibernating ones. These baseline data could be used for health monitoring and disease diagnostics in bullfrogs artificial farming and serve as general reference values for future studies on the physiology of this species. Key words: Bullfrogs, hibernation, hematology, serum biochemistry.

Metabolic Rate of Diploid and Triploid Edible Frog Pelophylax esculentus Correlates Inversely with Cell Size in Tadpoles but Not in Frogs.

In multicellular organisms, cell size may have crucial consequences for basic parameters, such as body size and whole-body metabolic rate (MR). The hypothesis predicts that animals composed of smaller cells (a higher membrane surface-to-cell volume ratio) should have a higher mass-specific MR because a large part of their energy is used to maintain cell membranes and ionic gradients. In this article, we investigated the link between cell size and MR in diploid and triploid tadpoles and froglets of the hybridogenetic frog Pelophylax esculentus. In our previous study, we showed that triploids had significantly larger cells (erythrocytes, hepatocytes, and epidermal cells were measured). Therefore, we hypothesized that triploid tadpoles and froglets would have a lower standard metabolic rate (SMR). Our study demonstrated for the first time two distinct effects of polyploidy/cell size on MR within a single species developing in both aquatic and terrestrial habitats. As we hypothesized, diploid tadpoles had a higher SMR than triploids, whereas in froglets, ploidy did not affect the SMR. We also found that the water temperatures in which tadpoles were reared had no effect on the SMR of froglets after metamorphosis. Based on our results and other reports, we suggest that cell size may have more consequences for whole-body MR in aquatic habitats than in terrestrial habitats because oxygen is less available in water and its availability in relation to oxygen demand decreases with temperature.