Whole Genome Sequencing and Annotation of Naematelia aurantialba (Basidiomycota, Edible-Medicinal Fungi)

Naematelia aurantialba is a rare edible fungus with both nutritional and medicinal values and especially rich in bioactive polysaccharides. However, due to the lack of genomic information, researches on the mining of active compounds, artificial breeding and cultivation, genetics, and molecular biology are limited. To facilitate the medicinal and food applications of N. aurantialba, we sequenced and analyzed the whole genome of N. aurantialba for the first time. The 21-Mb genome contained 15 contigs, and a total of 5860 protein-coding genes were predicted. The genome sequence shows that 296 genes are related to polysaccharide synthesis, including 15 genes related to nucleoside-activated sugar synthesis and 11 genes related to glucan synthesis. The genome also contains genes and gene clusters for the synthesis of other active substances, including terpenoids, unsaturated fatty acids, and bioactive proteins. In addition, it was also found that N. aurantialba was more closely related to Naematelia encephala than to Tremella fuciformis. In short, this study provides a reference for molecular cognition of N. aurantialba and related researches.

Culex quinquefasciatus larvae development arrested when fed on Neochloris aquatica

Culex quinquefasciatus is a cosmopolitan species widely distributed in the tropical and subtropical areas of the world. Due to its long history of close association with humans, the transmission of arboviruses and parasites have an important role in veterinary and public health. Adult females feed mainly on birds although they can also feed on humans and other mammals. On the other hand, larvae are able to feed on a great diversity of microorganisms, including microalgae, present in natural or artificial breeding sites with a high organic load. These two particularities, mentioned above, are some of the reasons why this mosquito is so successful in the environment. In this work, we report the identification of a microalga found during field sampling in artificial breeding sites, in a group of discarded tires with accumulated rainwater. Surprisingly, only one of them had a bright green culture without mosquito larvae while the other surrounding tires contained a large number of mosquito larvae. We isolated and identified this microorganism as Neochloris aquatica, and it was evaluated as a potential biological control agent against Cx. quinquefasciatus. The oviposition site preference in the presence of the alga by gravid females, and the effects on larval development were analyzed. Additionally, microalga effect on Cx. quinquefasciatus wild type, naturally infected with the endosymbiotic bacterium Wolbachia (w+) and Wolbachia free (w−) laboratory lines was explored. According to our results, even though it is chosen by gravid females to lay their eggs, the microalga had a negative effect on the development of larvae from both populations. Additionally, when the larvae were fed with a culture of alga supplemented with balanced fish food used as control diet, they were not able to reverse its effect, and were unable to complete development until adulthood. Here, N. aquatica is described as a biological agent, and as a potential source of bioactive compounds for the control of mosquito populations important in veterinary and human health.

Entomological Surveillance in Former Malaria-endemic Areas of Southern Italy

Malaria still represents a potential public health issue in Italy, and the presence of former Anopheles vectors and cases imported annually merit continuous surveillance. In areas no longer endemic, the concurrent presence of gametocyte carriers and competent vectors makes re-emergence of local transmission possible, as recently reported in Greece. In October 2017, due to the occurrence of four suspected introduced malaria cases in the province of Taranto (Apulia region), entomological investigations were performed to verify the involvement of local anopheline species. In 2019–2020 entomological surveys were extended to other areas historically prone to malaria between the provinces of Taranto and Matera and the province of Foggia (Gargano Promontory). Resting mosquitoes were collected in animal shelters and human dwellings, larvae were sampled in natural and artificial breeding sites, and specimens were both morphologically and molecularly identified. A total of 2228 mosquitoes were collected, 54.3% of which were anophelines. In all the investigated areas, Anopheles labranchiae was the most widespread species, while Anopheles algeriensis was predominant at the Gargano sites, and Anopheles superpictus and Anopheles plumbeus were recorded in the province of Matera. Our findings showed a potentially high receptivity in the surveyed areas, where the abundance of the two former malaria vectors, An. labranchiae and An. superpictus, is related to environmental and climatic parameters and to anthropic activities.

Structural Abnormalities of Spermatozoa in Triploid Gynogenetic Crucian Carp (Carassius auratus)

The spermatozoa of triploid gynogenetic crucian carp (Carassius auratus) (3nDTCC) possess a spermatogenesis process with a normal genetic background. However, the genetic materials of these spermatozoa do not completely inherit gynogenetic progeny in general. Understanding the intrinsic mechanism may be helpful for developing breeding strategies of gynogenetic fishes. In this study, the spermatozoa ultrastructure was systematically studied in diploid red crucian carp and 3nDTCC to demonstrate their cytological structural differences. In addition, the artificial breeding tests of 3nDTCC(♀) with different ploidy spermatozoa were performed to verify the contributions of genetic materials from 3nDTCC spermatozoa to the gynogenesis progeny. Furthermore, the mRNA expression of centriole-related genes (i.e., cep57, cetn1, rootletin, and nek2) involved in spermatozoa packaging was also determined by quantitative real-time PCR (qPCR) to illustrate the molecular expression characteristics of the spermatozoa packaging process in 3nDTCC. The results reveal the adaptive features of spermatozoa in 3nDTCC, including the loose midpiece structure, abnormal head structure, and abnormal expression of centriole-related genes, which may influence the motility of spermatozoa and make it not involved normally in the genetic composition of the gynogenesis offspring.

Sex ratio, gonadal and condition indexes of the Asiatic hard clam, Meretrix meretrix in Marudu Bay, Malaysia

Duisan L, Salim G, Ransangan J. 2021. Sex ratio, Gonadal and Condition indexes of the Asiatic Hard Clam, Meretrix meretrix in Marudu Bay, Malaysia. Biodiversitas 22: 4895-4904. Asiatic hard clam, Meretrix meretrix is one of the important shellfishery resources in Marudu Bay, Sabah, Malaysia. It is among the most popular clam species being widely traded in the local wet markets around Sabah, Malaysia. Unfortunately, the shellfishery management for this species has not been well established. In addition to overexploitation, habitat destruction is also one of the significant threats to this species due to the extensive land use of the coastal areas in Sabah. Hence, conservation and breeding efforts for this species are greatly required. Therefore, the current study was conducted to examine the sexual maturity of the clam with respect to shell length classes for artificial seed production purposes. For this study, a total of 86 clam specimens were randomly collected from mudflats in Marudu Bay. The specimens were utilized for gonad histological and condition analyses. The clams were grouped into three shell length classes; (3.00-4.99) cm, (5.00-6.99) cm, and (7.00-8.99) cm prior to the analyses. Results showed the natural stock of the Asiatic hard clams in Marudu Bay was dominated by females (1.39:1) over males with no hermaphroditism observed. The gonadal index was recorded higher among clams with shell lengths between 5.00 and 6.99 cm. The condition index analysis also recorded high (>4.0) for clams in all the shell length classes. The findings of this study suggest that the clams with shell lengths between 5.00 cm and 7.00 cm are already fully matured and can be utilized as a broodstock candidate for an artificial breeding program in the hatchery.

Rapid authenticity testing of artificially bred green turtles (Chelonia mydas) using microsatellite and mitochondrial DNA markers

Sea turtles are threatened by climate change and human activity, and their global populations continue to decline sharply. The Chinese government encourages artificial breeding of sea turtles to reduce the use of wild populations. However, artificial breeding of sea turtles is still fairly difficult, and some facilities may illegally purchase wild turtle eggs and then sell incubated turtles by marketing them as artificially bred turtles, which adds another threat to an already endangered species. Therefore, it is necessary to find a reliable method to distinguish the authenticity of artificially bred individuals. In this study, we investigated a turtle farm in southern China, that contained more than 400 green turtles, which were claimed to have been bred in captivity. Parentage testing of turtles from this farm was successfully conducted using two nuclear microsatellites combined with a mitochondrial D-loop DNA marker. Genetic matching of all 19 adults and randomly selected 16 juvenile turtles revealed that none of the juvenile turtles had a matching parent combination among the adult turtles. Therefore, we speculated that the green turtles in this farm were from the wild and that their origin of birth was mainly the Sulu Sea. The methods and molecular markers used in this study could be a reference for rapid authenticity testing of green turtles in future forensic enforcement and population management.

One hundred typical mistakes and violations of biotechnics of artificial breeding of Pacific salmon

The article lists the main and typical mistakes in the process of artificial breeding of Pacific salmon. All errors and violations are grouped by the periods of the production process (stages of the biotechnical chain), starting from working with producers and ending with the release of juveniles into natural reservoirs and watercourses. In addition, the degree of severity, economic and environmental consequences of such violations of biotechnics – immediate or delayed in their manifestations-are briefly described.

Status of Chinese Carp Fisheries in Tunisian Freshwater Reservoirs: Threats and Opportunities

The current paper aims to diagnose the state of fisheries of three Chinese carp species whish have been introduced in Tunisian reservoirs since 1981: (silver carp Hypophthalmichthys molitrix, herbivorous carp Ctenopharyngodon idella and bighead carp Aristichthys nobilis) and seeks to study the benefits and risks associated with their introduction. Chinese carps cannot reproduce naturally in freshwater reservoirs. Eventually, artificial breeding operations and seeding of the dams with farm-produced fry are carried out by the Technical Centre of Aquaculture every year. Statistical analyses have shown a strong correlation between the landed quantity and the number of fries stocked each year. The impact assessment showed that the risks and benefits associated with the introduction of the three species are variable. Regarding their benefits, it was clear that the herbivorous carp has provided effective and sustainable control of the extensive development of aquatic vegetation in the eutrophic reservoirs and canal systems. The value of the other two species, though, remains less obvious, particularly for the bighead carp. The consequences of their introduction on ecosystems and native species seem to be negligible, especially when the densities are low. Eventually, it seems judicious to increase the stocking of the herbivorous carp, silver carp and bighead carp in Tunisian reservoirs.

Optimization of Hormone for Artificial Breeding and Seed Production of Clarias batrachus (Linnaeus, 1758) Under Captive Condition

Aims: The study aimed to develop brood stock of Magur (Clarias batrachus), artificial breeding and seed production under captive condition using growth hormones in north-eastern Bangladesh. Study Design: Fifteen pairs of brood Clarias batrachus were used in this experiment. Brood fishes were reared up to maturation for spawning operation in the farm by providing artificial diet for 4-5 months before onset of breeding season. In the present experiment, the brood fishes were induced with three growth hormones viz., Ovupin (100 mg dompridone and 0.2 mg S-GnRHa) at the rate of 1 ml.kg-1 body weight, Flash (20 mg S-GnRHa, 10 mg dompridone IP and propylene glycol) at the rate of 1 ml.kg-1 body weight and Human Chorionic Gonadotropin (HCG) hormone at the rate of 2272 IU.kg-1 body weight; respectively. The broods were injected with single injection in all treatments. Place and Duration of Study: The present study was conducted on induced spawning of Magur (Clarias batrachus) at the Reliance Aqua Farm, Boilor, Trisal of Mymensingh district from March to August, 2016. Methodology: Sexually mature healthy, uninjured male and female fishes were collected from the broodstock ponds for induced breeding. The fishes were transferred in the clean and germ free conditioning tanks for about 6-7 hours. During conditioning, continuous splash of water was given by keeping the male and female separate. The fishes were then weighed individually and injected intramuscularly with Ovupin, Flash and HCG hormone respectively. Only females were injected at 45° angle of the caudal peduncle. About 23-24 hours of post-injection the testes from males were dissected and mixed with stripping eggs for fertilization. Results: The incubation period for fertilized eggs were 23-24 hours for all the treatments. Fertilization rates were 78.20±0.52, 93.09±0.61 and 81.60±0.97 % and hatching rates were 54.93±0.61, 75.77±0.47 and 64.41±0.71 % in Ovupin, Flash and HCG treatments, respectively. Conclusion: This study revealed higher fertilization (93.09 %) and hatching (75.77 %) rate was achieved with Flash hormone. Therefore, Flash hormone could be effective for the artificial breeding and seed production of Magur (Clarias batrachus).