The predominance of heterozygotes found in wild goldfish of lake Erie at the gene locus for sorbitol dehydrogenase

Sorbitol dehydrogenase (SDH) found in liver, kidney, and gonads of the goldfish (Carassius auratus) appears to be specified by a single autosomally inherited gene locus and, when subjected to electrophoresis, SDH behaves as a tetramer in that a homozygote gives a single band, while a heterozygote shows five bands of SDH. In a population of the wild goldfish inhabiting Lake Erie, two alleles which specify electrophoretic variants S^A and S^B coexist in nearly equal frequency, and there appears to be a slight excess of heterozygotes. Sixty-seven of the 109 wild goldfish were S^A/S^B heterozygotes. In the domesticated goldfish, on the other hand, an allele for the S^B variant appears to be a very rare allele. Only one of the 100 domesticated goldfish studied here and none of the 100 domesticated goldfish studied in Germany was an S^A/S^B heterozygote.Supported in part by a grant (CA 05138) and grant (FR 00433) from the National Cancer Institute, U.S. Public Health Service.On leave from McMaster University, Hamilton, Ontario, Canada.     

No evidence of UV cone input to mono- and biphasic horizontal cells in the goldfish retina

Many animal species make use of ultraviolet (UV) light in a number of behaviors, such as feeding and mating. The goldfish (Carassius auratus) is among those with a UV photoreceptor and pronounced UV sensitivity. Little is known, however, about the retinal processing of this input. We addressed this issue by recording intracellularly from second-order neurons in the adult goldfish retina. In order to test whether cone-driven horizontal cells (HCs) receive UV cone inputs, we performed chromatic adaptation experiments with mono- and biphasic HCs. We found no functional evidence of a projection from the UV-sensitive cones to these neurons in adult animals. This suggests that goldfish UV receptors may contact preferentially triphasic HCs, which is at odds with the hypothesis that all cones contact all cone-driven HC types. However, we did find evidence of direct M-cone input to monophasic HCs, favoring the idea that cone–HC contacts are more promiscuous than originally proposed. Together, our results suggest that either UV cones have a more restricted set of post-synaptic partners than the other three cone types, or that the UV input to mono- and biphasic HCs is not very pronounced in adult animals.     

The fine structure of the fin musculature in two teleost species with different swimming modes,the puffer,Tetraodon steindachneri,and the goldfish,Carassius auratus

Summary Puffer fish (Tetraodon steindachneri) can execute precise maneuvers due to their highly specialized mode of propulsion. In the conventional locomotion exemplified by the goldfish (Carassius auratus), the fish thrusts are generated by lateral beating of the caudal fin. In contrast, the puffer generates its propulsive force by very rapid undulating movements of the pectoral, dorsal and anal fins. The fine structure of the fin muscles is identical in the two species of fishes, despite the differences in fin movement; cytologically, the fibers are intermediate between those of red and of white muscle. On the other hand, both the fusion frequency and the number of motor endplates are considerably higher in the fin muscles of the puffer than in those of the goldfish.     

Domestication patterns in common bean (Phaseolus vulgaris L.) and the origin of the Mesoamerican and Andean cultivated races

Chloroplast DNA polymorphisms were studied by PCR sequencing and PCR-restriction fragment length polymorphism in 165 accessions of domesticated landraces of common bean from Latin America and the USA, 23 accessions of weedy beans, and 134 accessions of wild beans covering the entire geographic range of wild Phaseolus vulgaris. Fourteen chloroplast haplotypes were identified in wild beans, only five of which occur also in domesticated beans. The chloroplast data agree with those obtained from analyses based on morphology and isozymes and with other DNA polymorphisms in supporting independent domestications of common bean in Mesoamerica and the Andean region and in demonstrating a founder effect associated with domestication in each region. Andean landraces have been classified into three different racial groups, but all share the same chloroplast haplotype. This suggests that common bean was domesticated once only in South America and that the races diverged post-domestication. The haplotype found in Andean domesticated beans is confined to the southern part of the range of wild beans, so Andean beans were probably domesticated somewhere within this area. Mesoamerican landraces have been classified into four racial groups. Our limited samples of Races Jalisco and Guatemala differ from the more widespread and commercially important Races Mesoamerica and Durango in types and/or frequencies of haplotypes. All four Mesoamerican races share their haplotypes with local wild beans in parts of their ranges. Independent domestications of at least some of the races in Mesoamerica and/or conversion of some locally adapted wild beans to cultigens by hybridization with introduced domesticated beans, followed by introgression of the domestication syndrome seem the most plausible explanations of the chloroplast and other molecular data.     

The level and composition of free fatty acids in the plasma of freshwater fish in a post-absorptive condition

The level and fatty acid composition of plasma free fatty acids (FFA) were determined in four important aquaculture teleost species: goldfish (Carassius auratus), common carp (Cyprinus carpio), rainbow trout (Oncorhynchus mykiss) and tilapia (Oreochromis mossambicus). Plasma was obtained from animals after a 3 day fast in order to study the mobilization of fatty acids in a post-absorptive condition. Plasma [FFA] amounted to 0.95 in goldfish, 0.77 in both carp and rainbow trout and 0.30 μmol/ml in tilapia. The fatty acid composition was dominated by mono-unsaturates in goldfish and carp, whereas saturates were the main fatty acids in tilapia. The largest amount of PUFA was observed in rainbow trout (41%) which was considerably higher than in the other species (27–29%). The interspecies differences of plasma FFA levels and patterns are discussed in relation to the site of lipid storage, mobility and other factors.     

Genetic homeostasis and developmental stability in natural populations of bisexual (<Emphasis Type="Italic">Carassius auratus</Emphasis>) and unisexual (<Emphasis Type="Italic">C. gibelio</Emphasis>) goldfishes

One amphymictic diploid Carassius auratus, three apomictic triploids C. gibbelio, and a hybrid triploid Carassius auratus forms of goldfish were compared with respect to a set of characteristics of developmental stability: morphological variation, fluctuating asymmetry, and phenodeviations. It was found that C. gibbelio forms are characterized by lower levels both of morphological variation and fluctuating symmetry and more rare morphological abnormalties. A hybrid form Carassius auratus-gibelio was characterized by the intermediate values of the above-listed features. It is emphasized that phenotypic stabilization of apomictic forms is caused by two factors: its clone structure and actual developmental canalization. It is specified that promoted genetic homeostasis of the C. gibelio form does not give obvious adaptive advantages, as in the basic river basins of East and Central Europe. they are everywhere ousted by an amphimictic C. auratus.     

Histochemical detection of steroid synthesizing cells in the testes of goldfish,Carassius auratus,during the annual reproductive cycle

We investigated the sites of Δ⁵-3β-hydroxysteroid dehydrogenase (3 β-HSD) and glucose-6-phosphate dehydrogenase (G-6-PD) synthesis in the testes of goldfish, Carassius auratus, during the annual reproductive cycle. The histochemistry of fish gonads has been investigated previously in many species other than goldfish. The reproductive cycle of goldfish, is divided into five stages and the steroid synthesizing cells of the testes were studied during these stages, using histochemical techniques. We found that interstitial cells and seminiferous tubules are the main steroid synthesizing sites in testes of goldfish, and that enzyme activity was more intense in the interstitial cells than in the seminiferous tubules. During the pre-spawning months, 3 β-HSD and G-6-PD activities were weak compared to the spawning months.     

A comparative study of hearing ability in fishes: the auditory brainstem response approach

Auditory brainstem response (ABR) techniques, an electrophysiological far-field recording method widely used in clinical evaluation of human hearing, were adapted for fishes to overcome the major limitations of traditional behavioral and electrophysiological methods (e.g., invasive surgery, lengthy training of fishes, etc.) used for fish hearing research. Responses to clicks and tone bursts of different frequencies and amplitudes were recorded with cutaneous electrodes. To evaluate the effectiveness of this method, the auditory sensitivity of a hearing specialist (goldfish, Carassius auratus) and a hearing generalist (oscar, Astronotus ocellatus) was investigated and compared to audiograms obtained through psychophysical methods. The ABRs could be obtained between 100 Hz and 2000 Hz (oscar), and up to 5000 Hz (goldfish). The ABR audiograms are similar to those obtained by behavioral methods in both species. The ABR audiogram of curarized (i.e., Flaxedil-treated) goldfish did not differ significantly from two previously published behavioral curves but was lower than that obtained from uncurarized fish. In the oscar, ABR audiometry resulted in lower thresholds and a larger bandwidth than observed in behavioral tests. Comparison between methods revealed the advantages of this technique: rapid evaluation of hearing in untrained fishes, and no limitations on repeated testing of animals. Accepted: 8 August 1997     

Under-ice observations of behavior of selected native and exotic fishes of the St. Lawrence river system

Winter behavior of two native fishes (yellow perch, Perca flavescens, and killifish, Fundulus heteroclitus) and an exotic (goldfish, Carassius auratus) were studied in an outdoor experimental pond to quantify and link behavior to environmental conditions, and to identify interactions among the species that now co-occur in the wild. Killifish had high mortality and were not observed. However, contrary to our predictions, perch and goldfish had good overwinter survival and remained active in winter, and neither species spent most of their time in the warmest layer of the water column. Only two instances of aggression were seen: in both, goldfish charged perch. Both species were found principally in groups (schools); goldfish spent 18% of their time in multispecies groups. © 1994 Wiley-Liss, Inc.     

The energetic cost of the fever response in three species of ectothermic vertebrates

Three species of ectothermic vertebrates: goldfish (Carassius auratus), green tree frogs (Hyla cinerea), and desert iguanas (Dipsosaurus dorsalis) were used in this study. Metabolic rates for each species were determined at the normal afebrile preferred body temperature and at the febrile preferred body temperature or other higher body temperatures. The febrile metabolic rate (or higher rate) was significantly greater than the afebrile metabolic rate (or lower rate) in each species. The average increase in energetic cost for goldfish and desert iguana was 64.5% while the increase for the green tree frog was between 24 and 70%.     

A model of MPTP-induced Parkinson's disease in the goldfish

Parkinson's disease (PD) has been modeled in humans, lower primates, and to a lesser extent in some other vertebrates by the administration of the potent neurotoxin 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP). The MPTP model has thus drawn considerable attention during the past 15 years, as a system to search for anti-PD drugs. It has been previously reported that a Parkinsonian syndrome can be elicited in the common goldfish (Carassius auratus) by a single dose of MPTP. This protocol describes the relatively simple and inexpensive MPTP model of PD in goldfish. The procedure takes 14-30 d, depending on how many animals are tested and on the planned study. The accessibility of the goldfish nervous system, neural density, the evolutionary equivalent subcortical circuitry and the greatly abbreviated blood-brain barrier of the goldfish brain, make it an attractive system for study of PD as well as potential drugs for therapy.     

Town Mouse, Country Mouse: adaptation and adaptability in Mus domesticus (M. musculus domesticus)

The generally accepted idea that the house mouse is a single, world-wide species which owes its success largely to commensalism with man is wrong. There are at least five European and two Asian species lumped together under the name Mus musculus, plus another fourteen Asian species in the same genus. The house mouse of western Europe is the one that has been introduced to the Americas and Australasia, as well as being domesticated in the laboratory and ‘fancy’ strains; it is properly described as Mus domesticus. A complication of this particular species is the existence of chromosomal races involving the fusion of pairs of chromosomes, apparently at random. These races seem to be reproductively isolated from normal (2n = 40) mice. They have been described in southern Europe and northern Britain. Genetical studies of wild-living mice have shown the operation of powerful natural selection, contrary to earlier assumptions that most of the polymorphic variation in the species (especially that revealed by electrophoresis) was neutral. The effects of such selection are reduced (but not eliminated) by the deme structure of established mouse populations; this social structure is much less rigid than some laboratory experiments have suggested, because of opportunism by individual mice in replacing dead or debilitated animals, and filling new niches as these become available. Virtually every mouse population is unique, since a population tends to be founded by a small group of animals drawn from a genetically variable ancestral population. This differentiation has allowed laboratory workers to develop inbred strains with characteristic properties; it has also resulted in over 130 sub-species being described from wild caught animals. A substantial proportion of these latter have probably arisen by instant sub-speciation through the founder effect. This is well illustrated by the mice of the Faroe islands, which are often quoted as standard examples of extremely rapid evolution. The adaptive properties of the house mouse that have made it such an effective pest and such a good laboratory animal have enabled it to colonize habitats as different as Antarctic tundra and tropical atolls. The species is an ideal one for the general biological task of dissecting the traits that contribute to this adaptability; the material is largely available for this task in the diversity of local forms established in different habitats and characterized genetical varieties maintained in the laboratory. More is known about M. domesticus than any other mammal, except possibly man; the time is ripe for fusing laboratory work on reproduction, mortality, and behaviour with the information increasingly coming from field studies of wild-living animals.     

A parkinsonian syndrome induced in the goldfish by the neurotoxin MPTP.

Parkinson's disease has been modeled in humans, lower primates, and to a lesser extent in some other vertebrates by administration of the potent neurotoxin MPTP (1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine). The MPTP model has thus drawn considerable attention as a system to search for anti-Parkinson's disease drugs, although the cost and scarcity of primates has limited extensive applications. We now report that a parkinsonian syndrome can be elicited in the common goldfish (Carassius auratus) by a single dose of MPTP. The syndrome is characterized by profound bradykinesia (slow movement), the full extent of which is reached 3 days after MPTP administration. The reduction in movement is paralleled by loss of dopamine and norepinephrine from the forebrain and midbrain and in other brain regions as well. The toxic oxidative product of MPTP, MPP+, is also accumulated predominantly in forebrain and midbrain, and pretreatment with the monoamine oxidase blocker tranylcypromine substantially reduces accumulation of the toxic metabolite. A barely perceptible coarseness in balance adjustment also occurs in treated animals. The MPTP-treated goldfish recover normal movement and normal brain monoamine levels within 10-13 days after administration of the drug. We interpret these and other data to indicate that MPTP can induce a Parkinson's disease-like syndrome in the goldfish that is similar in many aspects to the syndrome induced by MPTP in humans and other primates. This remarkable parallel may permit the goldfish to supplement expensive and scarce primates for the purpose of searching and screening neuroprotective drugs with specific relevance to Parkinson's disease.     

Origin of Chinese Goldfish and Sequential Loss of Genetic Diversity Accompanies New Breeds

Background

Goldfish, Carassius auratus, have experienced strong anthropogenic selection during their evolutionary history, generating a tremendous extent of morphological variation relative to that in native Carassius. To locate the geographic origin of goldfish, we analyzed nucleotide sequences from part of the control region (CR) and the entire cytochrome b (Cytb) mitochondrial DNA genes for 234 goldfish and a large series of native specimens. Four important morphological characteristics used in goldfish taxonomy–body shape, dorsal fin, eye shape, and tailfin–were selected for hypothesis-testing to identify those that better correspond to evolutionary history.

Principal Finding

Haplotypes of goldfish rooted in two sublineages (C5 and C6), which contained the haplotypes of native C. a. auratus from southern China. Values of F _ST and N_m revealed a close relationship between goldfish and native C. a. auratus from the lower Yangtze River. An extraordinary, stepwise loss of genetic diversity was detected from native fish to goldfish and from Grass-goldfish relative to other breeds. Significantly negative results for the tests of Tajima’s D and Fu and Li’s D* and F* were identified in goldfish, including the Grass breed. The results identified eye-shape as being the least informative character for grouping goldfish with respect to their evolutionary history. Fisher’s exact test identified matrilineal constraints on domestication.

Conclusions

Chinese goldfish have a matrilineal origin from native southern Chinese C. a. auratus, especially the lineages from the lower Yangtze River. Anthropogenic selection of the native Carassius eliminated aesthetically unappealing goldfish and this action appeared to be responsible for the stepwise decrease in genetic diversity of domesticated goldfish, a process similar to that reported for the domestication of pigs, rice, and maize. The three-breed taxonomy–Grass-goldfish, Egg-goldfish, and Wen-goldfish–better reflected the history of domestication.     

Effect of alimentary deprivation on quantitative and time characteristics of nutrition of the goldfish in norm and under action of adrenalin

Effects of the intraperitoneally administered adrenalin (0.14 mg/kg) on volume and time characteristics (duration) of the individual, grouped, and summarized nutrition was studied in goldfish Carassius auratus (L.) previously kept on normal and restricted (for 10 and 15 days) ration. The fish on restricted ration demonstrated the two-phase alimentary response to the adrenalin injection similar with that in normally feeding fish: a decrease in volume and in the grouped and summarized duration of nutrition in the first phase of the hormone action and an increase-in the second phase; however, the value of the effect in the first phase was lower, while in the second phase-higher than in the fish that obtained before the experiment the sufficient amount of food. Duration of individual nutrition increased in all fish groups, including the control one, the maximal increase being observed in goldfish submitted to alimentary deprivation. The content of glycogen in hepatopancreas of the normally fed goldfish by the end of experiment exceeded that in fish restricted in nutrition 4.5–6 times. The obtained results confirm the suggestion that a decrease of level of reserved substances in the body leads to reduction of susceptibility of fish to the stress hormoneadrenalin and, hence, to a change of the value of its effects on the goldfish food-procuring activity, with preservation of dynamics of parameters.     

Effects of lanthanum on sodium and chloride fluxes in the goldfishCarassius auratus

Summary The effect of lanthanum (La³⁺) on Na⁺ and Cl^– fluxes and on gill potentials was investigated in the goldfish,Carassius auratus. Initially La³⁺ caused large increases in both influx and efflux but after 15 min these decreased with influx returning to near normal levels while effluxes remained elevated, leading to a significant net loss of ions. Both La³⁺ and Ca²⁺ influenced gill potentials in an identical way. Possible physiological effects of La³⁺ on gill ion exchange mechanisms are discussed.     

Linking Morphological and Behavioural Defences: Prey Fish Detect the Morphology of Conspecifics in the Odour Signature of their Predators

Predation is a strong selective force acting on both morphology and behaviour of prey animals. While morphological defences (e.g. crypsis, presence of armours or spines or specific body morphologies) and antipredator behaviours (e.g. change in foraging or reproductive effort, or hiding and fleeing behaviours) have been widely studied separately, few studies have considered the interplay between the two. The question raised in our study is whether antipredator behaviours of a prey fish to predator odours could be influenced by the morphology of prey conspecifics in the diet of the predator. We used goldfish (Carassius auratus) as our test species; goldfish exposed to predation risk significantly increase their body depth to length ratio, which gives them a survival advantage against gape‐limited predators. We exposed shallow‐bodied and deep‐bodied goldfish to the odour of pike (Esox lucius) fed either form of goldfish. Deep‐bodied goldfish displayed lower intensity antipredator responses than shallow‐bodied ones, consistent with the hypothesis that individuals with morphological defences should exhibit less behavioural modification than those lacking such defences. Moreover, both shallow‐ and deep‐bodied goldfish displayed their strongest antipredator responses when exposed to the odour of pike fed conspecifics of their own morphology, indicating that goldfish are able to differentiate the morphology of conspecifics through predator diet cues. For a given individual, predator threat increases as the prey become more like the individual eaten, revealing a surprising level of sophistication of chemosensory assessment by prey fish.