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1.
In vitro culture has great potential for the propagation of freshwater mussels in both commercial and conservation aquaculture. The use of in vitro techniques precludes the need for host fish, thus decreasing costs and increasing efficiency. However, protocols are still lacking for many species that grow substantially during the parasitic stage. In this study, we tested the effects of taurine addition, serum type and source of lipids on the survival rate and increase in length of Margaritifera margaritifera larvae during the initial stage of culture (first 11 days of exposure to media). Our results show that taurine has no significant effect on the early survival rate of glochidia; however, the possible importance of this amino acid in subsequent stages is discussed. The use of an emulsified lipid mixture instead of traditional fish oil showed significantly higher rates of survival. Finally, the addition of serum showed variable effects, with both horse serum and newborn calf serum having higher survival in trials using mussel populations from different sources. These findings can contribute to the invention or improvement of in vitro protocols for species growing during infection and at the same time show the potential that early survival assessments could have for the development of in vitro methods in species with long parasitic stages. 相似文献
2.
Invasive Chinese pond mussel Sinanodonta woodiana threatens native mussel reproduction by inducing cross‐resistance of host fish 
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下载免费PDF全文 Seth W. Donrovich Karel Douda Věra Plechingerová Kateřina Rylková Pavel Horký Ondřej Slavík Huan‐Zhang Liu Martin Reichard Manuel Lopes‐Lima Ronaldo Sousa 《水产资源保护:海洋与淡水生态系统》2017,27(6):1325-1333
3.
The growth and morphological development including fins, spine distribution and pigmentation of larval and juvenile of hatchery‐reared yellow puffer, Chonerhinos naritus were described to provide essential information on the early life history of this species. The total length (TL) of newly hatched larvae was 3.42 ± 0.23 (mean ± SD) mm, reaching 5.66 ± 0.38 mm on 5 days after hatched (DAH), 7.80 ± 0.28 mm on 11 DAH, 9.88 ± 0.40 mm on 27 DAH and 10.92 ± 0.58 mm on 30 DAH. The yolk was completely absorbed in preflexion larvae at 4 DAH. The mouth opening started at 3 DAH of yolk sac larvae, while the teeth appeared starting from preflexion larvae at 7 DAH. Overall aggregate fin ray numbers including caudal fin attained full complement in postflexion larvae at 27 DAH. Several melanophores with appearance of small stellate were first appeared dorsally on the head of flexion larvae at 13 DAH, expanded at the dorsal region of the head, above the eye in juveniles at 30 DAH. The spines first appeared in preflexion larvae of C. naritus at 7 DAH, covering the ventral skin region below pectoral fin base and expanded to the ventral part of the body and nearly covered the whole abdomen region before the anus and below the eyes in juveniles. C. naritus remain as larvae for approximately 29 days, during which they metamorphose to the juvenile stage prior to sexual maturation. Observations in larvae development of C. naritus revealed similar characteristics with other Tetraodontidae species. 相似文献
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Nematode parasites infecting the starry batfish Halieutaea stellata (Vahl) (Lophiiformes: Ogcocephalidae) from the East and South China Sea 下载免费PDF全文
下载免费PDF全文 The starry batfish Halieutaea stellata (Vahl) is a small, benthic fish found in Indo‐West Pacific Oceans. However, our present knowledge of the helminth parasites of this fish is still fragmentary. In this study, a total of 29 fish collected from the East and South China Sea were examined to determine the prevalence, intensity and species composition of helminth parasites in H. stellata. Using morphological and molecular approaches, four species of nematodes were found parasitic in this fish host, including the adults and fourth‐stage larvae of Raphidascaroides nipponensis Yamaguti 1941; adults and third‐stage larvae of Raphidascaris lophii (Wu 1949), third‐ and fourth‐stage larvae of Hysterothylacium larval type IV‐A of Shamsi, Gasser & Beveridge 2013 and third‐stage larvae of Hysterothylacium amoyense (Hsü 1993). Halieutaea stellata represents a new host record for the three last‐named nematodes. Raphidascaroides nipponensis with the highest prevalence (82.5%) and intensity (mean = 13.5) of infection was considered as the dominant parasite species in H. stellata. The detailed morphology of the different developmental stages of the four nematode species was studied using light and scanning electron microscopy. All nematode species were also genetically characterized by sequencing and analysing the internal transcribed spacer (ITS) of the ribosomal DNA. This study provides further data on the occurrence of nematode parasites in H. stellata and also contributes to facilitate an accurate and rapid diagnosis of the infection by these little‐known nematodes. 相似文献
6.
Heavy loads of parasitic freshwater pearl mussel (Margaritifera margaritifera L.) larvae impair foraging,activity and dominance performance in juvenile brown trout (Salmo trutta L.) 下载免费PDF全文
下载免费PDF全文 Karl Filipsson Tina Petersson Johan Höjesjö John J. Piccolo Joacim Näslund Niklas Wengström E. Martin Österling 《Ecology of Freshwater Fish》2018,27(1):70-77
The life cycle of the endangered freshwater pearl mussel (Margaritifera margaritifera) includes a parasitic larval phase (glochidia) on the gills of a salmonid host. Glochidia encystment has been shown to affect both swimming ability and prey capture success of brown trout (Salmo trutta), which suggests possible fitness consequences for host fish. To further investigate the relationship between glochidia encystment and behavioural parameters in brown trout, pairs (n = 14) of wild‐caught trout (infested vs. uninfested) were allowed to drift feed in large stream aquaria and foraging success, activity, agonistic behaviour and fish coloration were observed. No differences were found between infested and uninfested fish except for in coloration, where infested fish were significantly darker than uninfested fish. Glochidia load per fish varied from one to several hundred glochidia, however, and high loads had significant effects on foraging, activity and behaviour. Trout with high glochidia loads captured less prey, were less active and showed more subordinate behaviour than did fish with lower loads. Heavy glochidia loads therefore may negatively influence host fitness due to reduced competitive ability. These findings have implications not only for management of mussel populations in the streams, but also for captive breeding programmes which perhaps should avoid high infestation rates. Thus, low levels of infestation on host fish which do not affect trout behaviour but maintains mussel populations may be optimal in these cases. 相似文献
7.
Hossein Ouraji Khosro Jani Khalili Ghaffar Ebrahimi Seyed Ali Jafarpour 《Aquaculture International》2011,19(4):683-691
Kutum Rutilus frisii kutum is known as a valuable commercial species in the southern part of Caspian Sea. Artificial rearing of fry has been introduced
as an alternative to supply kutum fry in order to restock the kutum population in the Caspian Sea. The aim of this study was
to find the suitable time to transfer kutum larvae from live food to artificial feed. The experiment began on day 3 post-
hatching and lasted for 21 days. Mean initial weight of larvae was 4.5 mg. Five experimental groups including Group A (zooplankton
alone for 21 days), Group B (12 days zooplankton + 9 days artificial feed), Group C (8 days zooplankton + 13 days artificial
feed), Group D (4 days zooplankton + 17 days artificial feed) and Group E (artificial feed alone for 21 days) were considered
for this experiment. According to the obtained results, the specific growth rate of kutum larvae varied from 8.01 to 13.58%
day−1, and the highest and lowest specific growth rate were found in A and E treatments, respectively. The lowest mean body weight
(24.6 mg) was found in larvae fed on artificial feed for 21 days. However, survival rates of kutum larvae fed mixed zooplankton
for 8 and 12 days (85.83 and 89.33%, respectively) were comparable with those of larvae fed live food during the entire experiment
(91.6%). The lowest survival rate (69.16%) was found in larvae fed artificial feed during the entire experiment. 相似文献
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İhsan Çelik Pınar Çelik Şükran Cirik Mert Gürkan Sibel Hayretdağ 《Aquaculture Research》2012,43(9):1260-1275
The embryonic and larval development of black skirt tetra, Gymnocorymbus ternetzi, are described under controlled laboratory conditions. In addition, major histomorphological changes and the allometric growth patterns during larval development have been described. The laboratory‐reared broodstock, that is 1 year of age, were spawned. Hatching occurred 20–21 h after spawning at 24 ± 0.5°C. The cleavage was finished in 2 h and the early blastula stage occurred at 2:04 hours after spawning. The gastrulation started at 3:20 hours and 30% epiboly was observed at 3:34 hours after spawning. Eight‐somite stage was observed at 08:33 hours. And embryonic developmental stage was completed at 21 h after spawning. The newly hatched larvae were 1442 ± 14.3 μm in mean total length (TL). The mouth opened at 3 days after hatching (DAH). The yolk sac had been totally absorbed and the larvae started to swim actively within 3–4 days. Notochord flexion began at 11 DAH. The metamorphosis was completed and the larvae transformed into juveniles at 32 DAH. In this paper, the full developmental sequence from egg to juvenile of G. ternetzi is described for the first time. 相似文献
9.
Ofelia S. Reyes Marietta N. Duray Corazon B. Santiago Manuele Ricci 《Aquaculture International》2011,19(1):155-164
The free-living nematode, Panagrellus redivivus, was tested as live food for grouper Epinephelus coioides larvae during the first feeding stage. A series of experiments were conducted to determine the acceptability of the free-living
nematodes in grouper larvae at first feeding, the optimum nematode density and the response of the larvae to nutritionally
enriched nematode. All experiments were conducted in 200-L conical tanks filled with 150-L filtered seawater and stocked at
15 larvae L−1. Duration of feeding experiments was up to day 21 (experiment 1) and 14 days (experiment 2 and 3). Brachionus plicatilis and Artemia (experiment 1) and Brachionus plicatilis alone (experiment 2 & 3) was used as the control treatment. Observations indicated that the grouper larvae readily fed on
free-living nematodes as early as 3 days posthatching, the start of exogenous feeding. Optimum feeding density for the larvae
was 75 nematodes ml−1. The enrichment of cod liver oil or sunflower oil influenced the total lipids and n-3 highly unsaturated fatty acids of P. redivivus, which in turn influenced those of the grouper larvae, however, growth and survival of the larvae were not affected (P > 0.05). The results from this investigation showed that the nematode, P. redivivus, can be used as first live food for grouper larvae from the onset of exogenous feeding until they could feed on Artemia nauplii. 相似文献
10.
The aim of the present study was to clarify the effect of a feeding regimen of live food enriched with docosahexaenoic acid
(DHA) on the rates of abnormal morphology in larval brown sole Pseudopleuronectes herzensteini. Live foods were enriched with oil emulsion to produce both high-DHA and low-DHA content. Larvae in group 1 (control) were
fed low-DHA-content live foods throughout the experiment. Conversely, larvae in group 2 were fed high-DHA live foods from
15 days post-hatching (dph), when larvae were D stage. Larvae in group 3 were fed high-DHA live foods from 25 dph, when larvae
consisted mainly of E stage. The occurrence of normal morphology development in group 2 was significantly higher (P < 0.05) than those of groups 1 and 3, suggesting that normal morphology of brown sole is determined during the critical larval
period (D–E stages). 相似文献
11.
Effects of starvation on survival,growth and development of Exopalaemon carinicauda larvae 下载免费PDF全文
下载免费PDF全文 This study aimed at evaluating the effects of two starvation modes (fasting‐feeding mode and feeding‐fasting mode) on survival, growth and development of mysis larvae of Exopalaemon carinicauda. It showed that food restriction significantly affected the survival, growth and development in both starvation modes. With the extension of initial starvation period, a significantly reduced survival rate during metamorphosis was observed. In the fasting‐feeding mode, the duration of metamorphosis was extended and the body lengths of the individuals, which experienced successful metamorphosis to the post‐larval stage 1, were much shorter. In the feeding‐fasting mode, the extension of initial feeding period led to dramatically increased survival rate and body lengths, while there was no significant difference in duration of metamorphosis of those groups that reached to post‐larval stage. The 50% point‐of‐no‐return and the 50% point‐of‐reserve‐saturation were 3.85 days and 4.81 days respectively. The results of this study indicate that E. carinicauda mysis have the ability to withstand or recover from relatively extended starvation, but to ensure the success of commercial seedling, timely and adequate feeding is necessary. The information obtained from this study could provide a basis to optimize the feeding schedule of artificial seedling of E. carinicauda. 相似文献
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An experiment was conducted to evaluate the rearing performance of different larval stages for optimum growth and survival during fingerling production of Clarias batrachus with an aim to reduce the rearing time of the catfish larvae in a hatchery system. The larvae were reared for 5, 10 and 15 days before stocking them in the nursery tanks. No significant (P < 0.05) difference could be found in length increment at the end of first week of rearing. But the total length was reduced during rest three weeks in five days old larvae compared to that of other two higher age groups. In 5 days old larvae the reduced weight (P < 0.05) was observed during the entire rearing period. However, the specific growth rate (SGR) did not vary among the groups. The survival rate as well as total biomass was decreased while stocking five days old larvae for rearing, compared to that of other two age groups. 相似文献
14.
Jens‐Eike Taeubert Marco Denic Bernhard Gum Michael Lange Juergen Geist 《水产资源保护:海洋与淡水生态系统》2010,20(7):728-734
- 1. The complex life cycle of endangered European freshwater pearl mussel Margaritifera margaritifera L. involves an obligatory parasitic phase on a host fish. Knowledge on the host–parasite interaction and on the suitability of different host fish species and strains is required both for the management of wild fish and mussel populations as well as for improving the efficiency of captive breeding methods.
- 2. In this study, the suitability of different salmonid strains for hosting glochidia was tested, including Danube salmon (Hucho hucho L.) and three brown trout (Salmo trutta L.) strains from inside and outside the freshwater pearl mussel distribution range. All brown trout strains as well as Danube salmon were successfully infected with freshwater pearl mussel glochidia and encystment of mussel larvae was detected.
- 3. One brown trout strain originating from the natural pearl mussel distribution range was identified as the most suitable host, revealing the highest fish‐weight‐normalized infection rates and highest glochidial growth rates, whereas endemic Danube salmon was least suitable. Under natural conditions, the role of Danube salmon may be attributed to the long‐distance dispersal of glochidia in the Danube system, whereas sedentary brown trout appear to be the most important hosts at a local scale.
- 4. Successful infection of suitable hosts and the maintenance of these host–parasite systems in calcareous water were demonstrated in this study. These results indicate that neither the infection process nor the encystment phase of freshwater pearl mussels is dependent on low lime concentrations.
- 5. The results of this study suggest that careful selection and management of appropriate host fish strains is mandatory for sustainable conservation management of freshwater pearl mussel populations. Copyright © 2010 John Wiley & Sons, Ltd.
15.
Development and design of adequate feeding protocols on sea cucumber larvae are necessary for improvements on larvae growth, survival and production of competent juveniles. This work assessed the Holothuria arguinensis larvae growth and survival, fed with three different single microalgae diets of Chaetoceros calcitrans, Isochrysis galbana and Tetraselmis chui, and two microalgae diets based on a combination of C. calcitrans and T. chuii (C:T; 1:1) and C. calcitrans, T. chuii and I. galbana (C:T:I; 1:1:1) during 2 months. Holothuria arguinensis larvae fed with T:C:I, showed higher survival and larger larval and stomach sizes than the ones fed with the other diets. Comparing the results obtained from the single diets, H. arguinensis larvae fed with I. galbana grew and survived better during the first 5 days. However, higher growth was obtained on the larvae fed with C. calcitrans from day 5 to day 12; since this day, larvae fed with T. chuii showed the largest size. These results could be related to the different microalgae size and morphology, in addition to the nutritional value of the different microalgae used. However, no competent larvae that metamorphosed into doliolaria were obtained during this experiment. The tanks used were transparent, which could be causing light stress to the larvae, since competent larvae were obtained in opaque production tanks in our aquaculture installations during the same time period. The combined diet of C. calcitrans, T. chuii and I. galbana (C:T:I) could improve the growth and larvae competency of H. arguinensis. 相似文献
16.
Gavin L. Butler Stuart J. Rowland Peter R. Baverstock Stephen Morris 《Ecology of Freshwater Fish》2012,21(1):23-33
Abstract – Understanding the larval ecology of individual fish species is fundamental in ensuring their long‐term conservation. The endangered eastern freshwater cod, Maccullochella ikei, is endemic to the Clarence and Richmond River systems of north‐eastern New South Wales, Australia. Little is known about the behaviour of larval M. ikei in the wild, particularly before and after the swim‐up stage, and following dispersal from the nest site. The aims of this study were to quantify the swimming ability, depth selection, light preference and substrate selection of hatchling to day‐30 M. ikei under controlled laboratory conditions, and to describe its growth and development over the same period. Maccullochella ikei larvae grew constantly but not consistently during the experiment. Exogenous feeding commenced around day 12, prior to the full exhaustion of the yolk. Maximal swimming ability improved daily, but maximum swimming speed declined significantly between days 12 and 13 and remained low. Maccullochella ikei larvae were initially photonegative but were positively phototactic by day 10. Depth selection was for the benthos until day 8, beyond which time larvae dispersed to all depths when released. Substrate selection was for sand in younger larvae but changed to upstream substrates as the experiment progressed. The results of the current study suggest that the period between day 10 and day 20 is critical in the early ontogeny of M. ikei, when it switched phototrophic behaviour, transitioned from endogenous to exogenous feeding and experienced a decline in swimming ability. 相似文献
17.
Temperature effects on hatching and viability of Juvenile Gill Lice,Salmincola californiensis 下载免费PDF全文
下载免费PDF全文 Salmonids of the genus Oncorhynchus, distributed throughout the Pacific Rim, can be infected by the gill lice species Salmincola californiensis (Dana, 1852), which makes them one of the most broadly distributed gill lice species. Despite their broad distribution and valuable obligate salmonid hosts, relatively little is known about S. californiensis. We evaluated effects of temperature on timing of S. californiensis hatching and survival of copepodids, and provide information on brood size and variability. Our results suggest that temperature was a primary driver of timing of S. californiensis hatching and post‐hatching survival. Prior to this study, the free‐swimming stage of S. californiensis was reported to survive approximately 2 days without a suitable host. We observed active copepodids 13 days after hatch with some individuals from most (>90%) viable egg sacs at all temperature treatments surviving ≥5 days. Our findings indicate that warmer temperatures could increase development rates of gill lice at certain life stages, potentially increasing fecundity. This information coupled with predictions that warmer water temperatures could intensify crowding of coldwater fishes, stress, and parasite transmission suggests that climate change could exacerbate negative effects of S. californiensis on ecologically and economically important salmonids. 相似文献
18.
Yukinori Mukai Audrey Daning Tuzan Sitti Raehanah Muhamad Shaleh Bernardette Mabel Manjaji-Matsumoto 《Fisheries Science》2010,76(6):921-930
Larvae of the sutchi catfish Pangasianodon hypophthalmus hatch with morphologically immature features, but sensory organs develop rapidly as the fish grow. By 1 day old, yolk-sac
larvae showed notochord flexion, and by 2 days old larvae were observed to have consumed a large part of the yolk sac. At
this stage, larvae had well-developed eyes, olfactory organs with ciliated receptor cells, inner ears with semicircular canals,
and numerous taste buds, and they commenced ingestion of rotifers, Artemia nauplii, and artificial compound feed. Two-day-old larvae had many free neuromasts on the surface of the head and flanks
and clearly showed rheotaxis. By 20 days old, free neuromasts in postflexion larvae had sunk under the skin. At this later
stage, larvae swam against a water current and schooled along the side of the fish tank. Rapid development of sensory organs
and notochord flexion would be an adaptation for survival in conditions of flowing water, as in the Mekong River. In this
study, we show that development of the lateral line in the postflexion stage seems to be closely related to larval behavior,
suggesting that these developments could be essential for sutchi catfish larvae survival. 相似文献
19.
The present study provides information on the histomorphological development of digestive system of discus, Symphyosodon spp., larvae during the first month of life. Discus larvae are altricial at hatching, with an undifferentiated digestive
tract and a large yolksac, which is completely consumed within 7 days. The mouth opens 3 days after hatching (DAH) and the
larvae starts feeding on AF Artemia at 4 DAH when offered. At 3 DAH the digestive tract is differentiated with distinct esophagus, stomach anlage, and mid- and
hindguts. At 5 DAH, discus larvae is an active feeder, equipped with partly developed jaws and ossified gill arches and an
inflated swim bladder. The liver and pancreas are present and supranuclear inclusion vacuoles (SIV) appear in the hindgut
for the first time. Gastric glands in stomach were first observed 7 DAH and proliferated by 11–13 DAH. SIV were a common feature
in the midgut and hindgut epithelium until 15–23 DAH. Therefore, exclusive use of artificial diets should be postponed until
2–3 weeks after hatching. 相似文献
20.