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Goliath groupers (Epinephelus itajara) are large charismatic species, which are often residents in public aquaria. This study reports a novel approach to feeding techniques for three resident goliath groupers. Because of the size and depth of their exhibit, the groupers were conditioned to hand feed from aquarists. Daily food logs were recorded including the type and number of species, how often the groupers were fed, and how often they accepted the offered food. Mackerel, herring, and sardine represented the highest percentage of the diet, whereas capelin, squid, and shrimp were the lowest percentage. Over a one‐year period, records showed that grouper 1 and grouper 3 ate fairly consistently throughout the year. Grouper 2 had a higher degree of variation in his monthly feeding average with a decrease from May to September and an increase through April. Grouper 1 and grouper 3 took food from the aquarists most consistently with a monthly average of 88.8±10.8 and 89.7±6.15% of the time, respectively. Grouper 2 was not as consistent, hand feeding at only 74.5±16.2% of the time offered. Diet management and behavioral conditioning with the goliath groupers have established consistent husbandry records and therefore better monitoring of the individual fish's long‐term health status. Zoo Biol 27:414–419, 2008. © 2008 Wiley‐Liss, Inc.  相似文献   

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Environmental Biology of Fishes - Rare species necessitate alternative survey techniques and, in the case of exploited resources, any attempt to monitor their abundance with a meaningful benchmark...  相似文献   

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We examined the efficacy of androgens (1.0 mg/kg body mass), testosterone (T), 11-ketotestosterone (11-KT), 17alpha-methyltestosterone (MT), testosterone propionate (TP) or androgen mixture (T, MT and TP in an equal ratio), for induction of sex change in protogynous orange-spotted grouper, Epinephelus coioides. The spawning performance in sex-changed males was also investigated. MT and androgen mixture at a dose of 1.0 mg/kg BW induced a sex transition and completion of spermatogenesis up to the functional male phase. The androgen mixture was most effective. Significantly, higher plasma T levels were found in MT and androgen mixture groups compared to control and other androgen implantation (T, TP or 11-KT) groups. We found that plasma levels of estradiol-17beta (E2) or 11-KT were not different among treated groups. Sex-changed males could successfully fertilize mature eggs. Fertilization and hatching rates were of 23.5-70.4% and 8.4-44.6%, respectively. The data demonstrated that induction of sex change by exogenous androgens in groups could apply to the aquaculture field for seed production.  相似文献   

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Epinephelus itajara is one of the marine fish species most threatened for extinction and it is considered to be “critically endangered” by the IUCN. The present study evaluated the genetic diversity of the species and the genetic/evolutionary relationships of its populations along the Atlantic coast of South America. The results indicate relatively reduced genetic variation, re-emphasizing the low adaptive potential of the species. One of the populations presented relatively high degrees of genetic diversity and it is evolutionary isolated from the all other populations. The evidences indicate the existence of two Evolutionarily Significant Units comprising E. itajara in the Atlantic coast of South America and the conservation prospects for the species must take these evidences into account.  相似文献   

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Egerton  J. P.  Johnson  A. F.  Le Vay  L.  McCoy  C. M.  Semmens  B. X.  Heppell  S. A.  Turner  J. R. 《Coral reefs (Online)》2017,36(2):589-600
Coral Reefs - Fish spawning aggregations (FSAs) are vital life-history events that need to be monitored to determine the health of aggregating populations; this is especially true of the endangered...  相似文献   

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Epinephelus ongus forms spawning aggregations at specific reef sites at Okinawa. The aim of the present study was to describe the spawning behavior of E. ongus based upon underwater video imagery. Epinephelus ongus spawning is usually paired with courting males and females rushing upwards towards the surface during the spawning ascent, with a subsequent release of eggs at the apex of the ascent. In two of four spawning events we observed, however, the ascending pair was joined by additional males. Fish eggs collected at the site were identified as those of E. ongus and confirmed that this species spawns mainly at night during a slack tide. This study is the first documentation of E. ongus spawning behavior in the field.  相似文献   

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In the present study, we examined methods for the cryopreservation of Epinephelus septemfasciatus spermatozoa. The percent motility, average path velocity, and linearity of movement (LIN) of fresh and corresponding post-thaw sperm were evaluated. Sperm motility was investigated using computer-assisted sperm analysis. Five percent dimethyl sulphoxide (Me2SO) with 95% fetal bovine serum (FBS) was the most successful cryoprotectant diluent with a comparative post-thaw motility of 77.6 ± 8.5%; 5% dimethyl formamide was also effective. Fetal bovine serum was significantly better as an extender when compared with artificial seminal plasma, glucose, and trehalose solution. Sperm tolerated a wide range of cooling rates (from 27.1 to 94.3 °C min?1); however, the post-thaw motility of sperm cooled to ?30 °C was significantly lower than that of other cooled temperatures (?40 to ?70 °C). The velocity of post-thaw sperm was significantly lower than that of fresh sperm, although LIN remained the same. For effective cryopreservation of seven-band grouper sperm, samples should be diluted in 5% Me2SO with 95% FBS and cooled to at least ?40 °C before immersion in liquid nitrogen.  相似文献   

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Using Ringer solution as extender, the present study examined the protective effect of dimethyl sulphoxide (Me2SO; 8-12%, v/v) on the cryopreservation of giant grouper (Epinephelus lanceolatus) sperm. The cryopreserved sperm was then successfully applied in interspecific hybridization with tiger grouper (E. fuscoguttatus). Higher motility (90.56 ± 6.58%) and fertilization rate (69.61 ± 4.83%) was achieved in 10% Me2SO with Ringer solution as extender (dilution ratio 1:1), which should no significant difference in comparison with fresh sperm (95.88 ± 1.64% and 73.10 ± 1.28%). There were no statistical differences in both fertilization and hatching rates between hybrid and non-hybrid tiger grouper by using cryopreserved sperm for fertilization, but malformation rate of the hybrid was higher than non-hybrid (17%) (P < 0.05). Survival rate of the hybrid was lower than that of the controls at 15 days post hatching (23% vs 48%). However, hybrids showed survival rate equal to the controls at the end of the 60-day study period. Hybridization of E. fuscoguttatus x E. lanceolatus was successfully achieved using cryopreserved sperm from giant grouper. The cryopreservation of giant grouper sperm and its application in hybridization provided a technical support for further grouper breeding work.  相似文献   

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In the past, two euphausiid species prevailed in the high Arctic Kongsfjorden, the arcto-boreal Thysanoessa inermis (Kroeyer, 1846) and Thysanoessa raschii (Sars. 1964). Both were considered expatriates from the Barents Sea or Norwegian Sea and non-reproductive due to low temperatures. The macro-zooplankton of the fjord has been studied as a component in an ecosystem context since 2006, including baseline investigation of distribution and functional performance of key species. In recent years, three additional krill species were regularly detected in the fjord and are the focus of an intensive long-term study. Of these species, Thysanoessa longicaudata (Kroeyer, 1846) and Meganyctiphanes norvegica (Sars, 1857) are typical for the boreal Atlantic whereas Nematoscelis megalops (Sars, 1883) has a broad distribution in temperate to subtropical provinces. Their occurrence in the Kongsfjorden clearly indicates increasing Atlantic influence. During the 2011 campaign, T. raschii was observed spawning in the field for the first time and showed development up to the naupliar stage in the laboratory. Should more evidence of reproduction be encountered in any of the five krill species in the Kongsfjorden in the future, it will be taken as an indication of a changing environment concerning temperature and food web composition.  相似文献   

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Solid tumor growth is dependent on the development of an adequate blood supply. For years, sprouting angiogenesis has been considered as the exclusive mechanism of tumor vascularization. However, in recent years, another mechanism of tumor vascularization has been identified that does not involve endothelial cells, a process called vasculogenic mimicry (VM). VM describes the unique ability of highly aggressive tumor cells to form vessel-like networks by virtue of their high plasticity. VM has been observed in several tumor types, and its occurrence is strongly associated with poor prognosis. This review focuses on signaling molecules and cascades involved in VM. In addition, the clinical significance of VM regardless of anti-angiogenesis treatment modalities is described.  相似文献   

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We, the Editors and Publisher of Anthropological Forum, have retracted the following article:

Maurice Godelier (2019) Comment on Anthropology: Why it Matters, Anthropological Forum, DOI:10.1080/00664677.2019.1615255

Due to some communication issues, another version of this review has been published elsewhere. Accordingly, this version of the review has been retracted from publication.

We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions.

The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”.  相似文献   

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Interferon (IFN) plays crucial roles in innate immune responses against viral infections. In the present study, we report cloning and characterization of the IFN gene from the sevenband grouper (Epinephelus septemfasciatus), and the anti-viral effects of its recombinant IFN protein in vivo. The isolated cDNA from sevenband grouper IFN encoded a protein consisting of 178 amino acids, and its first 22 amino acids represented a putative signal peptide. We named the identified sevenband grouper IFN gene as SgIFNa1 based on the result from phylogenetic analysis that categorized the deduced protein sequence into fish IFNa family. The expression of SgIFNa1 mRNA in the head kidney cells was induced by synthetic Poly(I:C), which is known as an inducer of IFN. It has also been confirmed that injection of recombinant SgIFNa1 protein (rSgIFNa1) upregulates expression of the Mx gene, which is known as an IFN-responsive gene, in head kidney cells. Moreover, we observed that preliminarily injection of rSgIFNa1 provided significant protection against a lethal challenge of nervous necrosis virus (NNV), which is a serious disease of sevenband grouper. These results demonstrate that SgIFNa1 has anti-viral activity and the administration of rSgIFNa1 to sevenband grouper is effective in preventing severe symptom development after NNV infection.  相似文献   

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