Genome of the Giant Panda Roundworm Illuminates Its Host Shift and Parasitic Adaptation

Baylisascaris schroederi, a roundworm (ascaridoid) parasite specific to the bamboo-feeding giant panda (Ailuropoda melanoleuca), represents a leading cause of mortality in wild giant panda populations. Here, we present a 293-megabase chromosome-level genome assembly of B. schroederi to infer its biology, including host adaptations. Comparative genomics revealed an evolutionary trajectory accompanied by host-shift events in ascaridoid parasite lineages after host separations, suggesting their potential for transmission and rapid adaptation to new hosts. Genomic and anatomical lines of evidence, including expansion and positive selection of genes related to the cuticle and basal metabolisms, indicate that B. schroederi undergoes specific adaptations to survive in the sharp-edged bamboo-enriched gut of giant pandas by structurally increasing its cuticle thickness and efficiently utilizing host nutrients through gut parasitism. Additionally, we characterized the secretome of B. schroederi and predicted potential drug and vaccine targets for new control strategies. Overall, this genome resource provides new insights into the host adaptation of B. schroederi to the giant panda as well as the host-shift events in ascaridoid parasite lineages. Our findings on the unique biology of B. schroederi will also aid in the development of prevention and treatment measures to protect giant panda populations from roundworm parasitism.     

Observations on the dynamics of worm burdens in lambs infected daily with Ostertagia circumcincta

Hong C., Michel J. F. and Lancaster M. B. 1987. Observations on the dynamics of worm burdens in lambs infected daily with Ostertagia circumcincta.International Journal for Parasitology17: 951–956. Groups of lambs were infected daily with either 250, 500 or 1000 Ostertagia circumcincta larvae and the course of their worm burdens by post mortem examination at five intervals of time was studied. The number of worms appeared to be related to the rate of intake of larvae. A morphometric study of female worm lengths and observations on the incidence of reduced vulval flaps indicated that the population of worms turned over rapidly. The response of a small number of lambs appeared to be abnormal.     

Some larval ascaridoids from south-eastern queensland marine fishes

A survey of 123 species of fishes from southeastern Queensland during 1975 revealed in 47 species nine distinct larval types of ascaridoid nematodes: Anisakis Type I, Terranova Types I and II, Contracaecum Types I and II, and Thynnascaris Types I, II, III and IV. These larvae are described and figured.     

Populations of strongyloid nematode infective stages in sheep pastures: Comparison between direct pasture sampling and tracer lambs as estimators of larval abundance

Waller P.J., Dobson R.J., Donald A.D. and Thomas R.J. 1981. Populations of strongyloid nematode infective stages in sheep pastures : comparison between direct pasture sampling and tracer lambs as estimators of larval abundance. International Journal for Parasitology11: 359–367. Over a 2-year period, numbers of infective larvae in samples of pasture herbage, and numbers of worms in previously worm-free “tracer” lambs allowed 4 weeks grazing, were compared as estimators of the abundance of infective larvae on pastures.Transformation of sample estimates of infective larval numbers per 100 g herbage dry matter (DM) and of worm numbers in tracer sheep, according to the expression y = log₁₀ (x+25), was effective in stabilizing variances. Estimates of error variance for each technique did not differ significantly among the genera Haemonchus, Ostertagia or Trichostrongylus and the pooled estimate for the tracer sheep method was 4 times greater than that for pasture sampling. From these results, more tracer sheep than pasture samples would be required to achieve the same level of precision with the two techniques. Using conventional statistical methods, the effects of numbers of pasture samples or tracer sheep on the size of the difference between two means which can be detected as significant and on the width of the confidence interval about a single mean, are illustrated. These can be used as a guide in the choice of sample sizes. Error variances for Nematodirus spp. were significantly less than for the other genera by pasture sampling, and greater by the tracer sheep technique. Possible reasons for this are discussed, but it is concluded that pasture sampling is likely to be much the more precise method for estimating Nematodirus spp. infective larval availability.Changes with time in infective larval abundance, for Haemonchus, Trichostrongylus and Nematodirus spp. which were present in moderate to low numbers, followed similar trends by both techniques. However, for Ostertagia spp. larvae, which were much more abundant, peak levels were defined more sharply and occurred earlier by pasture sampling than by the tracer method. It is suggested that worm counts from tracer sheep, especially those grazing for 4 weeks rather than shorter periods, may systematically underestimate the infective larval population on pasture at high levels of abundance owing to density-dependent worm loss.     

Kinetics of primary and secondary infections with Strongyloides ratti in mice

Dawkins H. J. S. and Grove D. I. 1981 Kinetics of primary and secondary infections with Strongyloides ratti in mice. International journal for Parasitology11: 89–96. The kinetics of infection with S. ratti were quantitated in normal and previously exposed C57B1 /6 mice. In primary infections, larvae penetrated the skin rapidly and were seen in peak numbers 12 h after infection. By 24 h after infection, larval numbers had declined appreciably and there was a slow decrease in numbers thereafter. Larvae were first observed in the lungs at 24 h and maximal recovery occurred at 48 h. It is thought that larval migration through the lungs is rapid. Worms were first seen in the intestines two days after infection. Maximum numbers were seen on the fifth day and worm expulsion was complete by day 10. Two moults took place in the small intestine during days 3 and 4 after infection. Rhabditiform larvae were first noted on the fourth day after infection. Mice exposed to S. ratti four weeks previously had significantly less larvae in the skin 4 and 12 h after infection but by 24 h there was no difference when compared with mice with primary infections. Peak recovery of larvae from the lungs occurred 24 h after infection; significantly less larvae were recovered on days 2 and 3 when compared with normal mice. There was a marked reduction in the adult worm burden in the gut; the number of worms recovered was less than one fifth of that seen in primary infections. Those worms which did mature were less fecund and were expelled from the intestines within 7 days of infection. It is suggested that in previously exposed animals, the migration of larvae from the skin is hastened, many of these larvae are destroyed in the lungs and that expulsion of worms which do mature in the intestines is accelerated.     

Host-induced effects on the morphology of Ostertagia circumcincta in grazing sheep

Waller P. J. and Thomas R. J. 1978. Host-induced effects on the morphology of Ostertagia circumcincta in grazing sheep. International Journal for Parasitology8: 365–370. Morphological changes are described in adult Ostertagia circumcincta recovered from lambs slaughtered monthly from June to November. Comparisons were made between continuously grazed principal lambs exposed to infection for increasingly long periods, and tracer Iambs exposed for only four weeks. Lambs were either slaughtered immediately off pasture or held 2 weeks under worm free conditions before slaughter. Although no resistance to establishment of infection occurred, shown by comparable worm burdens of principals and tracers, a rapid parasite population turnover was observed in the principal lambs which ceased once the lambs were removed from the infected pasture. Significantly fewer adult female Ostertagia with fully developed vulval flaps were recorded in principals compared to tracers. Such differences are considered to be primarily host induced responses which rapidly come into play, evidenced by the entire populations of developing female worms in tracers slaughtered immediately off pasture showing arrested vulval flap development after they had completed development in those tracers held for a further two weeks. A progressive reduction in the proportion of adult male worms also occurred in the principal lambs. Population density was shown to have an inverse correlation with worm size. By analogy, it is suggested that seasonal change in the presence of cuticular inflations in Haemonchus contortus females with linguiform vulval flaps may be primarily host induced, rather than a change in the relative fitness of discrete genotypes.     

Ascaridoid parasites infecting in the frequently consumed marine fishes in the coastal area of China: A preliminary investigation

Marine fishes represent the important components of the diet in the coastal areas of China and they are also natural hosts of various parasites. However, to date, little is known about the occurrence of ascaridoid parasites in the frequently consumed marine fishes in China. In order to determine the presence of ascaridoid parasites in the frequently consumed marine fishes in the coastal town Huizhou, Guangdong Province, China, 211 fish representing 45 species caught from the South China Sea (off Daya Gulf) were examined. Five species of ascaridoid nematodes at different developmental stages were detected in the marine fishes examined herein, including third-stage larva of Anisakis typica (Diesing, 1860), third and fourth-stage larvae of Hysterothylacium sp. IV-A of Shamsi, Gasser & Beveridge, 2013, adult and third-stage larvae of Hysterothylacium zhoushanense Li, Liu & Zhang, 2014, adults and third-stage larvae of Raphidascaris lophii (Wu, 1949) and adults of Raphidascaris longispicula Li, Liu & Zhang, 2012. The overall prevalence of infection is 18.0%. Of them, Hysterothylacium sp. IV-A with the highest prevalence (17.5%) and intensity (mean = 14.6) of infection was the predominant species. The prevalence and intensity of A. typica were very low (1/211 of marine fish infected with an intensity of one parasite per fish). The morphological and molecular characterization of all nematode species was provided. A cladistic analysis based on ITS sequence was constructed in order to determine the phylogenetic relationships of these ascaridoid parasites obtained herein. The present study provided important information on the occurrence and diagnosis of ascaridoid nematodes in the commercially important marine fishes from the South China Sea. The low level of infection and the species composition of ascaridoid nematodes seem to indicate the presence of low risk of human anisakidosis when local population consumed these marine fishes examined herein.     

Arrested development of the rabbit stomach worm Obeliscoides cuniculi: resumption of development of arrested larvae throughout the course of a single infection

Arrested development of the rabbit stomach worm Obeliscoides cuniculi: resumption of development of arrested larvae throughout the course of a single infection. International Journal for Parasitology 16: 47–54. Twenty rabbits were inoculated once with cold treated L3s of Obeliscoides cuniculi with a high propensity for arrest and killed in pairs at intervals over 234 days post-infection. An exponential decline in numbers of adult worms and arrested larvae was observed. Arrested larvae resumed development at a rate seven times greater than adults were lost and appeared to replenish the adult population. More male than female arrested larvae were intially established in rabbits but males resumed development at a greater rate than females. Egg and larval production were correlated with the number of female worms present at any one time. In a subsidiary study, arrested larvae were recovered from one rabbit and transferred sequentially through two further rabbits. These larvae resumed development at the same rate as larvae in the 20 rabbits. Both studies suggest that resumption of development is an intrinsic characteristic of the larvae themselves and may be genetically controlled.     

Effects of host endocrine gland removal on the permissive status of laboratory rodents to infection by Schistosoma mansoni

Knopf P. M. and Soliman M. 1980. Effects of host endocrine gland removal on the permissive status of laboratory rodents to infection by Schistosoma mansoni. International Journal for Parasitology, 10: 197–204. The capacity of Schistosoma mansoni to complete its life cycle was compared in CD-1 mice (permissive hosts) and Sprague-Dawley rats (nonpermissive hosts) from which the pituitary gland had been removed prior to infection with cercariae. Except for a modest decrease in egg burden, none of the parameters of worm life cycle assessed were affected in hypophysectomized mice. In contrast, all these parameters were affected in hypophysectomized rats, e.g. onset of adult worm elimination was delayed, worm development improved, oviposition increased and miracidia developed. Effects of removal from rats of the thyroid/parathyroid glands on the parasite life cycle were similar to hypophysectomy; adrenalectomy or gonadectomy were without affect. Differences between thyroidectomized and thymectomized rats are discussed. It is concluded that host hormones contribute to the nonpermissive status of rats to Schistosoma mansoni infections.     

In vivo effect of single oral dose of artemether against early juvenile stages of Schistosoma mansoni Egyptian strain

The current treatment and control of schistosomiasis, rely on a single drug, praziquantel, although, it has minor activity against juvenile stages of the parasite. Studies have shown that artemether (ART) exhibits effects against juveniles of Schistosoma mansoni Liberian and Puerto Rican strains, Schistosoma japonicum and Schistosoma haematobium. Aiming to assess the in vivo activity of single oral dose of ART against early juvenile stages of S. mansoni Egyptian strain, this study was established. Mice were treated with ART (400 mg/kg) at two time points evenly spaced over the period of larval development (7 and 21 days post-infection; pi), and a third treatment point (day 49 pi) was included to elucidate when susceptibility decreases. Administration of ART on day 7 pi reduced the total worm burden by 85.94%. The greatest reductions were seen when treatment was given on day 21 pi, with total and female worm burden reductions of 91.52% and 90.57%, respectively, and cessation of oviposition. Similar dose given on day 49 pi reduced total worm burden by 55.17% and female worm burden by 66.51%. Moreover, it induced significant reduction in the tissue egg load and significant alterations in the oogram pattern with decreased immature eggs and increased dead eggs. Antipathological activities were evident in significant reductions in granulomata count and diameter. In conclusion, ART exhibits major in vivo schistosomicidal effects against the early larval migratory stages of S. mansoni Egyptian strain, mainly the 21-day old schistosomula, hence preventing disease progression and morbidity.     

The relationship of abnormal mucosal microtopography with distribution of Trichostrongylus colubriformis in the small intestines of lambs

The relationship of abnormal mucosal microtopography with distribution of Trichostrongylus colubriformis in the small intestines of lambs. International Journal for Parasitology4: 153–163. The distribution of T. colubriformis was studied by counting worms in sequential 1-m segments from the guts of 14 infected lambs. Mucosal morphology was described at corresponding 1-m intervals and compared with similar samples from uninfected controls. A mean of 90 per cent of worms was recovered in the first 6 metres of gut. Maximum worm counts occurred in the first (eight lambs) second (three lambs) or third (three lambs) metre. Less than 0·8 per cent of worms were found in the abomasa of five lambs. Flat mucosae or abnormal surface patterns were seen frequently in the anterior small intestine of infected lambs. Degree of mucosal abnormality was positively associated with magnitude of worm numbers/m, and negatively correlated with distance of the sample from the pylorus, by analysis of partial correlation of worm numbers/m, mucosal type score, and distance from the pylorus. Mucosae from areas with > 4000 worms/m tended to have significantly shorter villi than intestine of control lambs. Factors influencing worm distribution and pattern of establishment are discussed, as is the association of extreme villus atrophy with poor performance by infected lambs.     

The length of Ostertagia ostertagi in populations of uniform age

Michel J. F., Lancaster M. B. and Hong C. 1978. The length of Ostertagia ostertagi in populations of uniform age. International Journal for Parasitology8: 437–441. The conclusion that, in calves exposed to daily infection with larvae of Ostertagia ostertagi, adult worms are constantly lost and replaced was based, in part, on the observation that the length of the worms present decreased with time. The underlying assumption that worms do not shrink was examined in an experiment in which groups of calves received 8300, 25,000 and 75,000 larvae respectively in a single occasion and were killed at various times between the 20th and 132nd day thereafter.The length of the worms was inversely related to the initial worm burden but as worm burdens declined the worms did not grow. Instead, in the groups that received 25,000 and 75,000 larvae, decreases in worm length of 7% and 8% respectively were seen when most of the worms had been lost. Although it appears very probable that this was due to the more rapid loss of large worms than of small, the point could not be conclusively demonstrated.     

Development of anthelmintic resistance in nematodes from sheep in Australia subjected to different treatment frequencies

Development of anthclmintic resistance in nematodes from sheep in Australia subjected to different treatment frequencies. International Journal for Parasitology13: 125–132. In a three year (1978, 1979, 1980) field experiment in south-eastern Australia Merino weaner sheep were exposed to one of four worm control programmes. Sheep were treated either 50–51 times, 9–12 times, 3–6 times or 1–3 times annually with anthelmintic. Thiabendazole (TBZ) was used throughout 1978 and for the initial dose in 1980, levamisole (LEV) throughout 1979 and 1980. Sheep were replaced annually each December.During 1978 in vitro egg hatch tests indicated that populations of Haemonchus contenus with resistance factors to TBZ of 10·7, 10·0, 2.5 and 1·8 respectively were selected by these treatment frequencies. No resistance to LEV was detected in 1979 but during 1980 in vivo egg count reduction tests showed that highly resistant populations of Ostertagia spp. were selected in sheep dosed either 49 or 11 times. This was confirmed by an in vitro larval paralysis test. Partial resistance occurred where sheep were dosed 5 times but not where one dose was given. The only population of H. conlortus still present at the end of 1980 in sufficient numbers to allow eggs to be tested in vitro was from the sheep dosed once. This had retained its resistance to TBZ.     

The response of lambs to vaccination at weaning with irradiated Trichostrongylus colubriformis larvae: segregation into 'responders' and 'non-responders'

Dineen J. K., Gregg P. and Lascelles A. K. 1978. The response of lambs to vaccination at weaning with irradiated Trichostrongylus colubriformis larvae: segregation into ‘responders’ and ‘non-responders’. International Journal for Parasitology8: 59–63. Groups of colostrum fed and colostrum deprived lambs were vaccinated with irradiated Trichostrongylus colubriformis larvae at weaning (3 months) and challenged with normal infective larvae. As there was no significant difference between the worm counts of these groups after challenge, it was concluded that the failure of lambs, generally, to respond to vaccination as vigorously as mature sheep, was not due to ‘feed-back inhibition’ of the immune response by the action of maternal antibody.However the results showed that the lambs segregated into ‘responders’ and ‘non-responders’. The mean worm count of responders was 1560 whereas for non-responders this was 24,340. A responder was defined as an animal whose worm count was less than the lower limit of the 99 % confidence interval of unvaccinated controls. These results suggest that genetically-determined factors play an important role in the responsiveness of lambs to vaccination.Whereas counts of globule leucocytes in duodenal tissues were negatively correlated with worm counts (i.e. positively correlated with resistance), counts of both eosinophils and neutrophils were positively correlated with worm counts. These findings suggest that either globule leucocytes are involved in the resistance mechanism, or they are by-products of cellular events involved in resistance. On the other hand it is unlikely that either eosinophils or neutrophils are involved in the mechanism of resistance.     

The effect of acquired resistance on adult worms of Trichostrong ylus colubriformis in lambs

Dineen J. K. and Windon R. G. 1980. The effect of acquired resistance on adult worms of Trichostrongylus colubriformis in Lambs. International Journal for Parasitology10: 249–252. Wether lambs were classified as either responders or non-responders to vaccination and challenge with Trichostrongylus colubriformis. Worms recovered from these animals and unvaccinated controls were measured, eggs in utero counted and sex ratios (male/female) were determined for individual burdens. The results showed that all three parameters were reduced in responder lambs compared with non-responder and unvaccinated lambs and were positively correlated with worm counts in responder lambs whereas they tended to be negatively correlated with worm counts in non-responders and unvaccinated animals.These various effects of resistance on parasite development in responder lambs may be due to the action of endogenous inflammatory agents generated immunologically. On the other hand negative correlation between developmental parameters and worm burdens in non-responders and unvaccinated lambs suggests that development of parasites in heavy infections may be restricted by competition for a limiting physiological, spatial or nutritional resource of the host.     

Kinetics of primary and secondary infections with Taenia crassiceps metacestodes (Zeder, 1800) rudolphi, 1810 (cestoda: cyclophyllidea)

Siebert A. E. Jr., Good A. H. & Simmons J. E. 1978. Kinetics of primary and secondary infections with Taenia crassiceps metacestodes (Zeder, 1800) Rudolphi, 1810 (Cestoda: Cyclophyllidea). International journal for Parasitology8: 39–43. When three T. crassiceps metacestodes were inoculated intraperitoneally in mice as a primary infection, approximately 50% of the larvae recovered during the first 4 weeks after inoculation were found to be dead, while in mice primed by previous subcutaneous inoculation, about 85% of the larvae died. Larvae which survived the first 4 weeks following primary intraperitoneal inoculation reproduced asexually by exogenous budding and produced viable infections within the host mice. But larvae in secondary infections were encapsulated by host granulomata, failed to reproduce asexually, and did not produce viable infections. In mice given intraperitoneal inoculations of seven, ten and twenty metacestodes, fewer larvae were killed and little encapsulation response was noted, though host cells were common at the budding region of the larvae. Such a biphasic host-response to the infection has not previously been reported for larval cestode infections, and the reduction in host response associated with increased worm burdens may indicate possible depression of the host immune system.     

The effect of sire selection on the response of lambs to vaccination with irradiated Trichostrongylus colubriformis larvae

Dineen, J. K. and Windon, R. G. (1980). The effect of sire selection on the response of lambs to vaccination with irradiated Trichostrongylus colubriformis larvae. International Journal for Parasitology10: 189–196. Rams selected for responsiveness and unresponsiveness to vaccination with irradiated T. colubriformis larvae at an early age were mated to unselected random bred ewes. Progeny were vaccinated with 20,000 irradiated larvae at 8 and 12 weeks of age, given anthelmintic treatment at 16 weeks and challenged with 20,000 normai larvae at 17 weeks. The results, based on wether worm counts and ewe faecal egg counts, showed significant differences between responder and non-responder progeny. There was a significant correlation between worm counts and faecal egg counts of half-sibs from the same sire group. The occurrence of globule leucocytes was inversely related to worm burdens of wether progeny, however, no clear relationship was found with eosinophils. In vitro lymphocyte stimulation using T. colubriformis L₃ antigen, concanavalin A and lipopolysaccharide showed that statistically defined responder progeny, pooled from both responder and non-responder sire groups, gave higher responses than non-responder lambs after vaccination. The results confirm that genetically-determined factors are involved in the response of lambs to vaccination at an early age, and indicate that rapid genetic progress may be achieved in the type of mating usually carried out under fleld conditions.     

Effectiveness of Inpatient Insulin Order Sets Using Human Insulins in Noncritically Ill Patients in A Rural Hospital

Objective: Recent guidelines recommend a physiologic approach to non–intensive care unit (ICU) inpatient glucose management utilizing basal-bolus with correctional (BBC) insulin over traditional sliding-scale insulin monotherapy. Unfortunately, few studies exist using a BBC approach restricted to human insulins (regular and neutral protamine Hagedorn [NPH]). This study evaluated changes in provider prescribing patterns, effects on blood glucose, and safety with implementation of hospital order sets for BBC using human insulins.Methods: Order sets were developed for non-ICU inpatients, consisting of basal, prandial, and correctional insulin using NPH and regular human insulins. Evaluation compared a 4-month period before (admissions, n = 274) with a 4-month period after order set availability (n = 302). Primary outcome was change in insulin prescribing patterns. Secondary outcomes included use of nonpreferred diabetes treatments, hemoglobin A_1c testing, mean daily blood glucose, and incidence of hypoglycemia.Results: Use of BBC insulin regimen increased from 10.6 to 27.5% after order set implementation (P<.001). Use of oral antihyperglycemic agents decreased from 24.1 to 14.9% after implementation (P = .006). Hemoglobin A_1c testing rose from 50.0 to 62.3% after (P = .003). Mean daily blood glucose improved, with an estimated mean difference of 14.4 mg/dL (95% confidence interval, 2.2 to 26.5 mg/dL) over hospital days 3 through 9 (P = .02). There was no significant change in the incidence of moderate or severe hypoglycemia.Conclusion: Implementation of hospital-wide human insulin order sets led to improvements in prescribing practices and blood glucose control, without increasing the incidence of hypoglycemia. These order sets may be useful for facilities limited by formulary and cost considerations to the use of older human insulins.Abbreviations: BBC = basal-bolus with correctional insulin ICU = intensive care unit NPH = neutral protamine Hagedorn NPO = nil per os     

Thin layer chromatographic analyses of amino acids in Echinostoma revolutum (Trematoda) adults

Bailey R. S. Jr. and Fried B. 1977. Thin layer Chromatographic analyses of amino acids in Echinostoma revolutum (Trematoda) adults. International Journal for Parasitology7: 497–499. Thin layer Chromatographic analyses were made on free pool amino acids and those obtained from the incubate fluid of Echinostoma revolutum adults maintained in a non-nutrient salt solution. The major free pool amino acids detected were alanine, proline, serine and methionine. Alpha-amino-n-butyric acid was also tentatively identified. Amino acids detected in the incubate fluid were leucine-isoleucine, valine, methionine, tyrosine, proline, alanine, glutamic acid, serine, arginine, and aplha-amino-n-butyric acid was also tentatively identified. Amino acids presumably isolated from either worm egesta or the protonephridial system were qualitively similar to those obtained from worm incubate fluid.     

First report on embryonic and larval development of 2n/3n mosaic sterlet

Mosaicism is frequently observed in aquaculture practices, and it adversely affects the production as well as the restoration programme of the sturgeon. The purpose of the present study was the induction of 2n/3n mosaic in sterlet, Acipenser ruthenus L., and compare their embryonic and larval development with diploid control sterlet. Microsatellite DNA loci genotyping was conducted for the identification of the genotypes and parentage analysis. Embryonic development was monitored in experimental groups at every 24 h interval. Identification of individual stages of embryonic development was recorded based on a 36-degree scale of development. Additionally, the BW and body length (LT) of experimental fishes were taken during 110 days of the rearing period. The Fulton’s condition coefficient (F), length-weight parameters, and specific growth rate (SGR) coefficient were calculated. The analysis of embryonic development of the 2n/3n mosaic and the diploid control group did not show differences. However, higher mortality (88%) was observed in 2n/3n mosaic groups in comparison to the diploid control groups (55%). BW and body length of 2n/3n mosaic sterlet were slightly lower than the diploid control sterlet, but the differences were not statistically significant. F analysis did not confirm a lower growth performance of the fishes in the 2n/3n mosaic group. Microsatellite DNA loci genotyping confirmed both the incidence of polyspermy and retention of the second polar body. This paper presents the first report on embryonic development and growth performance of 2n/3n mosaic sturgeons.