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Clive M. Jones - One of the best experts on this subject based on the ideXlab platform.

  • A review of juvenile redclaw crayfish Cherax quadricarinatus (von Martens, 1898) aquaculture: global production practices and innovation
    Freshwater Crayfish, 2020
    Co-Authors: Damian P. Rigg, Jamie E. Saymour, Robert Courtney, Clive M. Jones
    Abstract:

    Abstract The Australian Redclaw crayfish, Cherax quadricarinatus, has been the subject of aquaculture development for more than 3 decades. Farm production from Australia and from around the world for this species has been relatively low, as suitable production technology continues to develop. The production of redclaw juveniles for the purpose of stocking to ponds for on-growing to marketable size, has been a particular constraint and new approaches to breeding and mass production of craylings have provided renewed impetus to industry expansion. This paper reviews the literature concerning redclaw juvenile production and provides a status report of current practices and innovations that may support further expansion of redclaw aquaculture.

  • Development of mass production hatchery technology for the redclaw crayfish, Cherax quadricarinatus
    Freshwater Crayfish, 2020
    Co-Authors: Clive M. Jones, Colin Valverde
    Abstract:

    Abstract Aquaculture production of redclaw Cherax quadricarinatus (von Martens) in Australia, has never reached the high level projections made in the 1990’s (Jones and Ruscoe 1996). This can be attributed to a range of factors, but the most significant is the supply of seedstock. Although redclaw is advantaged by its uncomplicated reproductive biology with no free-living larval stages, reliance on natural reproduction to generate juveniles for growout purposes is inefficient. An alternative approach involves the artificial incubation of fertilized eggs to improve both quality and quantity of juveniles produced. Suitable technology for such incubation was developed in Europe to support the on-going efforts to produce crayfish plague free juveniles for restocking to natural water bodies. This technology has now been adapted to suit redclaw and for the purpose of mass production of seed crayfish for aquaculture. This paper details the development of the AquaVerde hatchery system, and the challenges to see it develop into fully commercial production, that could support expansion of the redclaw farming industry, both in Australia and elsewhere in the world.

  • Selection for increased weight at 9 months in redclaw crayfish (Cherax quadricarinatus)
    Aquaculture, 2004
    Co-Authors: C.p. Mcphee, Clive M. Jones, Scott A Shanks
    Abstract:

    Two lines of redclaw crayfish (Cherax quadricarinatus) were maintained for four generations. One line was selected for increased harvest weight at 9 months, and the other maintained as an unselected control. To increase the heritability and limit inbreeding, lines were subdivided into cohorts with selection based on weight differences from cohort means. Selection increased harvest weight. In generation 4, weights averaged 61.6 g for the selected line and 49.3 g for the control line (s.e. diff. 2.3). The percentage of females carrying eggs at harvest was 9.8 in the selected line and 18.1 in the control line (s.e. diff. 4.0) suggesting that selection may have diverted energy from breeding activity to growth by delaying sexual maturity. Selection increased the carapace and tail length of females relative to their body weight. Estimates of realised heritabilities for harvest weight varied from 0.38±0.06 in year 1 to 0.13±0.02 in year 4. A practical selection program for redclaw could include periods of closed line selection alternating with test crossing with outside stocks to replenish genetic variation.

  • production of juvenile redclaw crayfish Cherax quadricarinatus von martens decapoda parastacidae ii juvenile nutrition and habitat
    Aquaculture, 1995
    Co-Authors: Clive M. Jones
    Abstract:

    Newly hatched redclaw crayfish Cherax quadricarinatus were reared for 39 days in aquaria using various combinations of food and habitat. Food treatments were fresh zooplankton and a high protein formulated flake diet. Habitat treatments involved the presence/absence of a floating aquatic macrophyte, Pistia stratiodes. Both survival and growth of juveniles were significantly influenced by the type of food and habitat. Fresh zooplankton produced the best growth. An interactive effect between food type and Pistia resulted in differential survival. Use of aquatic macrophytes for habitat in intensive juvenile production systems is not recommended.

  • Salinity tolerance of the tropical freshwater crayfish, Cherax quadricarinatus (von Martens)(Decapoda, Parastacidae)
    1995
    Co-Authors: Clive M. Jones
    Abstract:

    Adult freshwater crayfish, Cherax quadricarinatus, were held for 21 days at five different salinities to assess their tolerance to saline conditions and to gauge the effect on sensory characteristics (taste). Significant mortality occurred at salinities of 18 and 24 parts per thousand (ppt) during the last 7 days of the treatment period. There were no mortalities nor adverse indications at salinities of 0 (control), 6 and 12 ppt. Results suggest a developed capability to tolerate saline conditions. The physiological mechanisms responsible for salinity tolerance and flavour enhancement are discussed.

Laura Lopez S Greco - One of the best experts on this subject based on the ideXlab platform.

  • effects of atrazine on growth and sex differentiation in juveniles of the freshwater crayfish Cherax quadricarinatus
    Ecotoxicology and Environmental Safety, 2016
    Co-Authors: Camila Mac Loughlin, Ivana S Canosa, Gabriela Romina Silveyra, Laura Lopez S Greco, E. M. Rodríguez
    Abstract:

    Abstract The effect of the herbicide atrazine was assayed in early juveniles of the redclaw crayfish Cherax quadricarinatus . Four cohorts of juveniles (a total of 280 animals) were exposed for 4 wk to each one of three atrazine concentrations (0.1, 0.5 and 2.5 mg/L) or a control (0 mg/L), from a commercial formulation having 90% of active principle. At the end of the exposure, no significant (p>0.05) differences in either mortality or molting were noted. However, the weight gain and the protein content of abdominal muscle decreased significantly (p

  • sperm production in the red claw crayfish Cherax quadricarinatus decapoda parastacidae
    Aquaculture, 2009
    Co-Authors: Ana B Bugnot, Laura Lopez S Greco
    Abstract:

    Abstract The objective of this study is to evaluate the effect of body size, temperature and annual cycle on sperm production in Cherax quadricarinatus . Sperm count and sperm mortality were estimated, the reproductive system was weighted, and macro and microscopical analysis of the testes and vasa deferentia were conducted. Sperm count and weight of the reproductive system are strongly related to male size, in contrast to sperm mortality. The spermatophore structure presented macro and microscopical differences between sizes. Males higher in size have more adherent spermatophores. This species has a reproductive cycle related to sperm production. Sperm count and weight of the vasa deferentia rise in summer, while the weight of the testes increases in winter. During the spring, the sperm cord presents a higher density than in other seasons. The temperature seems to affect sperm production being 27 and 29 °C the best assayed conditions. The present results are relevant information to obtain the best sperm viability selecting male size, season of sampling and the best temperature for the reproductive stock and future assays of spermatophore cryopreservation for this species aquaculture.

  • development of the female reproductive system in the freshwater crayfish Cherax quadricarinatus decapoda parastacidae
    Invertebrate Biology, 2008
    Co-Authors: Fernanda J Vazquez, Carolina Tropea, Laura Lopez S Greco
    Abstract:

    . The differentiation of the female reproductive system from a macroscopic and microscopic point of view was studied in Cherax quadricarinatus. For this characterization, 184 females were dissected and processed for the histological analysis. From the differentiation of the ovary up to its maturity, three ovarian morphotypes could be distinguished macroscopically: parallel strands without any contact between them, an H-shaped ovary, and a Y-shaped ovary. These morphotypes were compared within the Astacida. Four ovarian developmental stages were recognized based on ovary color, and the histological structure and relative proportion of cellular types. The post-spawning ovary was also characterized. The components of the female reproductive system sheath were described and its modifications in the ovary and oviducts were determined and compared. Theoretical aspects of the study of sexual differentiation in C. quadricarinatus were discussed within a phylogenetic framework.

  • structural changes in the spermatophore of the freshwater red claw crayfish Cherax quadricarinatus von martens 1898 decapoda parastacidae
    Acta Zoologica, 2007
    Co-Authors: Laura Lopez S Greco, Fabiana Lo L Nostro
    Abstract:

    Lopez Greco, L.S. and Lo Nostro, F.L. 2007. Structural changes in the spermatophore of the freshwater ‘red claw’ crayfish Cherax quadricarinatus (Von Martens, 1898) (Decapoda, Parastacidae). —Acta Zoologica (Stockholm) 88: 000–000 The structure of the spermatophore was studied in Cherax quadricarinatus. Pieces of the distal vas deferens and transferred spermatophore from the females were fixed, cut and stained. Within the distal vas deferens, the primary layer and the secondary layer of the spermatophore were distinguishable. In the latter, two components were detected: cytoplasmic droplets and a homogeneous matrix. During the first 10 minutes post-extrusion the cytoplasmic droplets drastically changed from looking like ‘empty droplets’; at this time the spermatophore changed from a liquid stage to a sticky one. One hour after extrusion the spermatophore began to harden and within the first 24–48 h post-mating it was a solid and intense white structure tightly attached to the female; after 72 h it acquired a softer aspect, completely dehiscing between 96 and 120 h post-mating. Histologically, the primary layer maintained its integrity surrounding the spermatozoa while the secondary layer lost the cytoplasmic droplets. The spermatophore began to hydrate between 24 and 48 h and by 72–96 h many sections of the sperm cord began to coalesce. From 48 h post-mating some fissures appeared within the matrix that enlarged between 72 and 120 h. We propose that both manipulation by the female and hydration are the mechanisms involved in the release of the spermatozoa from the spermatophore.

  • morphology of the male reproductive system and spermatophore formation in the freshwater red claw crayfish Cherax quadricarinatus von martens 1898 decapoda parastacidae
    Acta Zoologica, 2007
    Co-Authors: Laura Lopez S Greco, Fernanda J Vazquez, E. M. Rodríguez
    Abstract:

    Lopez Greco, L.S., Vazquez, F. and Rodriguez, E.M. 2007. Sperm production and spermatophore formation in the freshwater ‘red claw’ crayfish Cherax quadricarinatus (Von Martens 1898) (Decapoda, Parastacidae). — Acta Zoologica (Stockholm) 88 : 223‐229. The morphology of the male reproductive system was studied in Cherax quadricarinatus . The testes and vasa deferentia were dissected, fixed, cut and stained. Testes appear as two parallel and opalescent strands; they present many testicular lobes, each lobe containing cells in the same stage of the spermatogenic cycle. A vas deferens arises from the external side of each testis and three parts were clearly distinguished: proximal vas deferens (PVD), middle vas deferens (MVD) and distal vas deferens (DVD). The PVD is opalescent and highly convoluted, the MVD is pale white in colour and convoluted, but wider in diameter than the PVD, while the DVD shows the widest diameter, is straight and is white in colour. A single-layered epithelium is recognized in the vas deferens; with cylindrical cells in the PVD and cuboid cells in the MVD and DVD. The formation of the spermatophore starts at the PVD, while the secondary layer of the spermatophore seems to be added at the MVD. At the DVD, the highly coiled spermatophore is surrounded by the periodic acid Schiff-positive sticky components of the secondary layer. Many aspects of spermatophore formation in C. quadricarinatus differ from those of other Astacida. The applied aspects of this study for aquaculture purposes are discussed.

Danli Wang - One of the best experts on this subject based on the ideXlab platform.

  • cDNA cloning and expression analysis of prophenoloxidase in Cherax quadricarinatus
    Journal of Fisheries of China, 2020
    Co-Authors: Danli Wang, Lanmei Wang, Jiayao Li, Yunlong Zhao
    Abstract:

    The Australian redclaw crayfish,Cherax quadricarinatus,is a crustacean belonging to the order Decapoda,family Parastacidae.In recent years,the cultivation of redclaw crayfish(Cherax quadricarinatus)is developing,and the disease of C.quadricarinatus was one of the major factors in its culture and even caused redclaw crayfish to die.The viral disease was found in polyculture of redclaw crayfish with Penaeus vannamei.To explore the pathogenic mechanism of C.quadricarinatus infected by WSSV(white spot syndrome virus),a prophenoloxidase gene(CqproPO)was cloned from haemocytes of C.quadricarinatus by Rapid Amplification Complementary DNA Ends(RACE)method,the proPO gene expression patterns in different tissues and the mRNA expression of proPO gene in hemocyte,hepatopancreas and gill tissues of C.quadricarinatus artificially infected by WSSV were studied.The results indicated that the full length cDNA of CqproPO consisted of 2 962 bp with a 1 998 bp Open Reading Frame(ORF),which encoded 665 amino acids,and the predicted molecular mass was 75.86 ku.Sequence analysis showed CqproPO contained two conserved copperbinding sites;The secondary and tertiary structure assay also showed that the CqproPO has α-helices and β-strands,which is delimiting a cavity where the hydrophobic ligands are bound just as other HCs.ORF contains two tyrosine kinase phosphorylation sites,13 casein kinase Ⅱ phosphorylation sites,7 protein kinase C phosphorylation sites,one dependent on cAMP-and cGMP protein kinase phosphorylation sites and three N-glycosylation sites,and these sites were structural basis of the physiological functions completed.The deduced amino acids sequence of CqproPO shared 79% homology with Procambarus clarkii and 74%,69%,67%,67% with Pacifastacus leniusculus,Nephrops norvegicus,Homarus americanus,Homarus gammarus respectively;Phylogenetic analysis revealed that CqproPO and prophenoloxidase from P.clarkii,P.leniusculus,N.norvegicus,H.americanus,H.gammarus and Panulirus longipes were in the same phylogenetic branch;The Realtime-PCR results showed that CqproPO was widely distributed,with the highest expression level in haemocytes,small amount of expression in intestine,antennal gland,gills,ovary and hepatopancreas,detectable expression level in stomach and muscle,while expression was almost undetectable in testis;The expression levels of prophenoloxidase(proPO)in haemocytes,hepatopancreas and gills from C.quadricarinatus were studied and compared by means of artificial WSSV infection.The results indicated that the expression level of CqproPO in the non-immunized infected group(group Ⅱ)and immunized infected group(group Ⅲ)reached the maximum at 12 h and 24h,which was 1.3-2.55 times higher than that in the control group,and was noticeably higher than the controls(P0.05).But the expression level of prophenoloxidase gene had sharply declined with the time extending of the infection.The expression level of proPO gene from crayfishes injected by immune polysaccharides before an infected virus(groupⅢ)were higher than the directly affected groups(groupⅡ)in haemocytes,hepatopancreas and gills,showing an immunoprotective rate of 51.86% 7 days after exposure.These observations indicated that the immunopotentiator could improve the innate anti-viral ability of the crustaceans against WSSV.

  • effects of white spot syndrome virus infection on immuno enzyme activities and ultrastructure in gills of Cherax quadricarinatus
    Fish & Shellfish Immunology, 2012
    Co-Authors: Danli Wang, Qun Wang, Lanmei Wang, Yunlong Zhao
    Abstract:

    Abstract In this study, we explored the pathogenic mechanism of white spot syndrome virus (WSSV) in crayfish, Cherax quadricarinatus, by investigating activities of enzymes related to innate immune function during infection. After 6–12 h of exposure to WSSV, the activities of four enzymes, phenoloxidase (PO), peroxidase (POD), superoxide dismutase (SOD) and lysozyme (LSZ), increased in the gills of C. quadricarinatus but then sharply decreased during longer infection times. Except for PO, the activities of other enzymes in the WSSV-infected crayfish (Group II) were significantly lower than those of the controls at 72 h post-exposure (P

Yunlong Zhao - One of the best experts on this subject based on the ideXlab platform.

  • cDNA cloning and expression analysis of prophenoloxidase in Cherax quadricarinatus
    Journal of Fisheries of China, 2020
    Co-Authors: Danli Wang, Lanmei Wang, Jiayao Li, Yunlong Zhao
    Abstract:

    The Australian redclaw crayfish,Cherax quadricarinatus,is a crustacean belonging to the order Decapoda,family Parastacidae.In recent years,the cultivation of redclaw crayfish(Cherax quadricarinatus)is developing,and the disease of C.quadricarinatus was one of the major factors in its culture and even caused redclaw crayfish to die.The viral disease was found in polyculture of redclaw crayfish with Penaeus vannamei.To explore the pathogenic mechanism of C.quadricarinatus infected by WSSV(white spot syndrome virus),a prophenoloxidase gene(CqproPO)was cloned from haemocytes of C.quadricarinatus by Rapid Amplification Complementary DNA Ends(RACE)method,the proPO gene expression patterns in different tissues and the mRNA expression of proPO gene in hemocyte,hepatopancreas and gill tissues of C.quadricarinatus artificially infected by WSSV were studied.The results indicated that the full length cDNA of CqproPO consisted of 2 962 bp with a 1 998 bp Open Reading Frame(ORF),which encoded 665 amino acids,and the predicted molecular mass was 75.86 ku.Sequence analysis showed CqproPO contained two conserved copperbinding sites;The secondary and tertiary structure assay also showed that the CqproPO has α-helices and β-strands,which is delimiting a cavity where the hydrophobic ligands are bound just as other HCs.ORF contains two tyrosine kinase phosphorylation sites,13 casein kinase Ⅱ phosphorylation sites,7 protein kinase C phosphorylation sites,one dependent on cAMP-and cGMP protein kinase phosphorylation sites and three N-glycosylation sites,and these sites were structural basis of the physiological functions completed.The deduced amino acids sequence of CqproPO shared 79% homology with Procambarus clarkii and 74%,69%,67%,67% with Pacifastacus leniusculus,Nephrops norvegicus,Homarus americanus,Homarus gammarus respectively;Phylogenetic analysis revealed that CqproPO and prophenoloxidase from P.clarkii,P.leniusculus,N.norvegicus,H.americanus,H.gammarus and Panulirus longipes were in the same phylogenetic branch;The Realtime-PCR results showed that CqproPO was widely distributed,with the highest expression level in haemocytes,small amount of expression in intestine,antennal gland,gills,ovary and hepatopancreas,detectable expression level in stomach and muscle,while expression was almost undetectable in testis;The expression levels of prophenoloxidase(proPO)in haemocytes,hepatopancreas and gills from C.quadricarinatus were studied and compared by means of artificial WSSV infection.The results indicated that the expression level of CqproPO in the non-immunized infected group(group Ⅱ)and immunized infected group(group Ⅲ)reached the maximum at 12 h and 24h,which was 1.3-2.55 times higher than that in the control group,and was noticeably higher than the controls(P0.05).But the expression level of prophenoloxidase gene had sharply declined with the time extending of the infection.The expression level of proPO gene from crayfishes injected by immune polysaccharides before an infected virus(groupⅢ)were higher than the directly affected groups(groupⅡ)in haemocytes,hepatopancreas and gills,showing an immunoprotective rate of 51.86% 7 days after exposure.These observations indicated that the immunopotentiator could improve the innate anti-viral ability of the crustaceans against WSSV.

  • effects of cold acclimation on the survival feeding rate and non specific immune responses of the freshwater red claw crayfish Cherax quadricarinatus
    Aquaculture International, 2018
    Co-Authors: Donglei Wu, Youhui Huang, Weiwei Lv, Minghai Chen, Yiming Li, Yunlong Zhao
    Abstract:

    The effect of cold acclimation on growth performance, non-specific immune responses, and expression level of HSP21 and CSP gene were studied in red claw crayfish (Cherax quadricarinatus) using a 4-week stress trial. We set a four-temperature gradient, with water temperatures of 25, 20, 15, and 9 °C, respectively. With the gradual decrease of temperature, the survival rate, feeding rate, and hepatopancreas index (HIS) of the red claw crayfish showed a decreasing trend. Decreased total hemocyte count (THC) and hemocyanin concentration were observed when water temperature decreased. The activities of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in the hepatopancreas and hemolymph all gradually declined with decreasing temperatures and then significantly lowered at 9 °C compared with those at 25 °C. The activity of glutathione peroxidase (GPx) in these two tissues showed in the opposite trend, indicating that they may have different regulation mechanisms. A gradual increase of malondialdehyde (MDA) concentration was detected in the hepatopancreas and hemolymph when the temperature decreased. Low temperature stress also affected the expression of heat shock proteins 21(HSP21) and cold shock domain protein (CSP). These results indicate that cold acclimation may induce oxidative stress on the crayfish and then cause oxidative damage and hemocyte apoptosis, as well as immunosuppression in Cherax quadricarinatus, which may finally affect the growth and survival of Cherax quadricarinatus.

  • Isolation and Characterization of Polymorphic Microsatellite Loci in the Redclaw Crayfish, Cherax quadricarinatus
    Journal of Aquaculture Research and Development, 2012
    Co-Authors: Lin He, Yunlong Zhao, Yaping Wang, Qing Li, Qun Wang
    Abstract:

    Here we developed and optimized 15 polymorphic microsatellites isolated from Cherax quadricarinatus enriched for CA repeats. We tested variability of these microsatellites in 60 unrelated individuals cultured in China. All microsatellite loci were polymorphic. Number of alleles per locus ranged from 2-7 while observed and expected heterozygosities ranged from 0.2549 to 0.8615 and from 0.3405 to 0.8174, respectively. Fourteen of the 15 microsatellites conformed to Hardy–Weinberg Equilibrium. These microsatellite loci developed here provide an important resource for studying genetic diversity and population structure in redclaw crayfi sh and potentially in other related species.

  • effects of white spot syndrome virus infection on immuno enzyme activities and ultrastructure in gills of Cherax quadricarinatus
    Fish & Shellfish Immunology, 2012
    Co-Authors: Danli Wang, Qun Wang, Lanmei Wang, Yunlong Zhao
    Abstract:

    Abstract In this study, we explored the pathogenic mechanism of white spot syndrome virus (WSSV) in crayfish, Cherax quadricarinatus, by investigating activities of enzymes related to innate immune function during infection. After 6–12 h of exposure to WSSV, the activities of four enzymes, phenoloxidase (PO), peroxidase (POD), superoxide dismutase (SOD) and lysozyme (LSZ), increased in the gills of C. quadricarinatus but then sharply decreased during longer infection times. Except for PO, the activities of other enzymes in the WSSV-infected crayfish (Group II) were significantly lower than those of the controls at 72 h post-exposure (P

  • isolation and characterization of fifteen microsatellite loci from the redclaw crayfish Cherax quadricarinatus
    Aquatic Living Resources, 2010
    Co-Authors: Lin He, Lili Chen, Yunlong Zhao, Yaping Wang, Qun Wang
    Abstract:

    The redclaw crayfish (Cherax quadricarinatus) is a freshwater crayfish species endemic to northern Australia and Papua New Guinea that is the focus of a growing culture industry in number of regions around the world. Here we isolated and characterized 15 microsatellite loci from Cherax quadricarinatus and tested variability of the loci in 66 unrelated cultured individuals. Thirteen of 15 microsatellite loci were polymorphic. Number of alleles per locus ranged from two to seven while observed and expected heterozygosities ranged from 0.172 to 0.985 and from 0.373 to 0.778, respectively. Eleven loci conformed to Hardy-Weinberg equilibrium in the sampled population. These microsatellite loci developed here provide an important resource for studying genetic diversity and population structure in redclaw crayfish and potentially in other related species.

E. M. Rodríguez - One of the best experts on this subject based on the ideXlab platform.

  • effects of atrazine on growth and sex differentiation in juveniles of the freshwater crayfish Cherax quadricarinatus
    Ecotoxicology and Environmental Safety, 2016
    Co-Authors: Camila Mac Loughlin, Ivana S Canosa, Gabriela Romina Silveyra, Laura Lopez S Greco, E. M. Rodríguez
    Abstract:

    Abstract The effect of the herbicide atrazine was assayed in early juveniles of the redclaw crayfish Cherax quadricarinatus . Four cohorts of juveniles (a total of 280 animals) were exposed for 4 wk to each one of three atrazine concentrations (0.1, 0.5 and 2.5 mg/L) or a control (0 mg/L), from a commercial formulation having 90% of active principle. At the end of the exposure, no significant (p>0.05) differences in either mortality or molting were noted. However, the weight gain and the protein content of abdominal muscle decreased significantly (p

  • Effects of Glyphosate on Growth Rate, Metabolic Rate and Energy Reserves of Early Juvenile Crayfish, Cherax quadricarinatus M.
    Bulletin of Environmental Contamination and Toxicology, 2014
    Co-Authors: L. Avigliano, A. V. Fassiano, D. A. Medesani, M. C. Ríos De Molina, E. M. Rodríguez
    Abstract:

    Early juveniles of the crayfish Cherax quadricarinatus were exposed for 60 days to 10 and 40 mg/L of pure glyphosate (acid form) in freshwater. Mortality was 33 % at the highest concentration, while no differences in molting were noted among treatments. After the first month of exposure, weight gain was significantly ( p  

  • Vitellogenin levels in hemolymph, ovary and hepatopancreas of the freshwater crayfish Cherax quadricarinatus (Decapoda: Parastacidae) during the reproductive cycle
    Revista De Biologia Tropical, 2012
    Co-Authors: Lilian Elizabeth Ferre, D. A. Medesani, C. Fernando Garcia, Matías Grodzielski, E. M. Rodríguez
    Abstract:

    The freshwater crayfish Cherax quadricarinatus is a tropical species of great interest for aquaculture. vitellogenin (vg), a lipoprotein precursor of the vitellum accumulated in spawned eggs, can be synthesized in the ovary and/or hepatopancreas of most crustaceans, being the hemolymph the way for transporting vg throughout the reproductive cycle. Concentration of vg in hemolymph, ovary and hepatopancreas of Cherax quadricarinatus adult females was measured by means of ELISA, specifically developed after purifying the native vg. Measurements were made at four periods of the reproductive cycle: pre-reproductive, mid-repro - ductive, late reproductive and post-reproductive. Besides, both hepatosomatic (HSI) and gonadosomatic (GSI) indexes were determined in each period. Significant variations in vg levels were detected in both hemolymph and hepatopancreas, being the highest values observed during the mid-reproductive period. Besides, such varia - tions were positively correlated to the HSI. A positive correlation between vg levels in hepatopancreas and ovary was also seen. These results support previous evidences about the central role of the hepatopancreas as a site of vg synthesis in the studied species, together with the relevancy of hemolymph for transporting vg from the hepatopancreas to the ovary. For aquaculture purposes, vg monitoring in hemolymph could be used as a non-injurious method, to check the reproductive activity of C. quadricarinatus females. Rev. Biol. Trop. 60 (1): 253-261. Epub 2012 March 01.

  • morphology of the male reproductive system and spermatophore formation in the freshwater red claw crayfish Cherax quadricarinatus von martens 1898 decapoda parastacidae
    Acta Zoologica, 2007
    Co-Authors: Laura Lopez S Greco, Fernanda J Vazquez, E. M. Rodríguez
    Abstract:

    Lopez Greco, L.S., Vazquez, F. and Rodriguez, E.M. 2007. Sperm production and spermatophore formation in the freshwater ‘red claw’ crayfish Cherax quadricarinatus (Von Martens 1898) (Decapoda, Parastacidae). — Acta Zoologica (Stockholm) 88 : 223‐229. The morphology of the male reproductive system was studied in Cherax quadricarinatus . The testes and vasa deferentia were dissected, fixed, cut and stained. Testes appear as two parallel and opalescent strands; they present many testicular lobes, each lobe containing cells in the same stage of the spermatogenic cycle. A vas deferens arises from the external side of each testis and three parts were clearly distinguished: proximal vas deferens (PVD), middle vas deferens (MVD) and distal vas deferens (DVD). The PVD is opalescent and highly convoluted, the MVD is pale white in colour and convoluted, but wider in diameter than the PVD, while the DVD shows the widest diameter, is straight and is white in colour. A single-layered epithelium is recognized in the vas deferens; with cylindrical cells in the PVD and cuboid cells in the MVD and DVD. The formation of the spermatophore starts at the PVD, while the secondary layer of the spermatophore seems to be added at the MVD. At the DVD, the highly coiled spermatophore is surrounded by the periodic acid Schiff-positive sticky components of the secondary layer. Many aspects of spermatophore formation in C. quadricarinatus differ from those of other Astacida. The applied aspects of this study for aquaculture purposes are discussed.