New records of the occurrence of Megaleporinus macrocephalus () (Characiformes, Anostomidae) from the basins of the Itapecuru and Mearim rivers in Maranhão, Northeastern Brazil

The “piaussu”, Megaleporinus macrocephalus is an anostomatid fish species native to the basin of the Paraguay River, in the Pantanal biome of western Brazil. However, this species has now been recorded in a number of other drainages, including those of the upper Paraná, Uruguay, Jacuí, Doce, Mucuri, and Paraíba do Sulrivers. This study presents two new records of the occurrence of M. macrocephalus, in the basins of the Itapecuru and Mearim rivers in the state of Maranhão, in the Brazilian Northeast. The piaussu is a large-bodied fish of commercial interest that is widely raised on fish farms, and its occurrence in the Itapecuru and Mearim rivers is likely the result of individuals escaping from fish tanks when they overflow during the rainy season. Morphological analyses and sequences of the Cytochrome Oxidase Subunit I (COI) gene confirmed the taxonomic identification of the specimens as M. macrocephalus. The COI sequences were 99.66% similar to those of M. macrocephalus deposited in the BOLDSystems database. These records extend the known distribution of M. macrocephalus to the basins of the Itapecuru and Mearim rivers in the Brazilian Northeast, highlighting a new case of introduction of exotic fish species into Brazilian river basins.

Climate Change in Fisheries and Aquaculture: Analysis of the Impact Caused by Idai and Kenneth Cyclones in Mozambique

Fisheries and Aquaculture are among the most popular activities in coastal regions of the world. In addition, both correspond to high-risk activities within a climate change context as they are vulnerable to environmental changes that threaten the socio-economic sustainability of the fishing communities that depend on fish for food security and income generation. In 2019, the central part of Mozambique was hit by two unprecedented cyclones: Idai and Kenneth that killed over 600 people and left nearly 2.2 million people in need of urgent assistance. The aim of the present study was to investigate the impacts these cyclones had on fisheries and aquaculture in the provinces of Sofala and Zambézia in Mozambique. The study further seeks to propose strategies that could be adopted by the communities to minimize the risks in the future. For the construction of the database, both secondary and primary data collection approaches were used to characterize the cyclone events. Secondary data was collected through sector reports and previously published articles, while primary data was collected through interviews with fishers, sector employees, and aquaculture producers in the affected provinces. The results revealed that these natural events had both a direct and indirect impact on fishing, as they affected more than 1,440 fishermen that lost 590 vessels, 1,800 fishing gear, and 67 boat engines in Sofala province. In Zambézia province, aquaculture producers lost 169 fish ponds, two cages, and 606,000 lost fry, while in Sofala province, 58 fish tanks, 204 cages, and 257,500 fish fry were lost. Overall, our study reveals the vulnerability of fisheries and aquaculture to extreme events particularly the cyclones in Mozambique. Lack of knowledge regarding climate change, advanced preventive measures, and poor adaptive capacity makes the sectors more vulnerable to disasters. Therefore, it is recommended to improve awareness programs, introduce measures and policies that promote resilience and optimum adaptive efficiency.

The Roman fish tanks of the Western Mediterranean basin as potential scenarios for research on sea-level changes

PurposeThis paper analyses Roman fish tanks, which have functional elements that could be used to research on palaeo-sea-levels. Thus, the conditions of 37 installations in the Western Mediterranean basin are reviewed to identify those that have the best environmental and constructive conditions to be analyzed.Design/methodology/approachThe methodology was largely based on the review of existing scientific bibliography dealing with sea-level variations from studies on historical constructions, existing historical documentation on Roman fish tanks on the Mediterranean coast, as well as the fieldwork carried out in fish tanks on the Mediterranean coasts.FindingsThe Roman coastal fish tanks located in the shoreline of the Western Mediterranean Sea have turned out to be an excellent indicator of sea-level changes. Nevertheless, current coastal retreat, erosion and storm surges are posing significant threats to their preservation, and they could be considered as a heritage at risk of disappearance. Moreover, variations in the tectonic behaviour of the different coastal sectors make it challenging to select these facilities as an indicator of the sea level.Originality/valueThe analysis of Late Holocene sea-level changes and palaeoenvironments from archaeological and biological evidences, although not without difficulties, is very convenient because it provides very precise data that cannot be obtained with other absolute dating methods. This approach is increasingly gaining popularity with researchers and is very innovative in its method of combining the results of several scientific disciplines.

Case of flexor tenosynovitis caused by Mycobacterium arupense

Mycobacterium arupense is a member of the Mycobacterium terrae complex (MTC) that is implicated in bone and joint infections, among others. This group of environmental pathogens can be found in soil, reclaimed and drinking water systems, rodents, fish tanks and bioaerosols in duck houses. Interestingly, while M. arupense is genotypically closely related to the other agents in the MTC, antibiotic susceptibility of these mycobacteria can vary widely and empiric antibiotic therapy is controversial. Our case report contributes to the very limited literature on M. arupense tenosynovitis—as only six cases have been reported since 2008—and sheds light on different courses of treatment. While previous cases have been successfully treated, a streamlined course of therapy for M. arupense tenosynovitis is still needed.

Aqualabyrinth – A New Enrichment for Laboratory Zebrafish Under Analysis for Future Production

In the field of laboratory animals, there have been considerable improvements in environmental enrichment for mammalian species, but little remains available for aquatic species, in particular fish. Recent publications have shown benefits in providing laboratory Zebrafish (Danio rerio) certain types of enrichments, such as substrate and plants. This research article proposes a novel tank enrichment called the Aqualabyrinth, and the benefit of its use in laboratory Zebrafish. While the enrichment won 3rd place at the 2020 Janet Wood Innovation Award (JWIA) competition, the Aqualabyrinth is not yet available on the market. This novel enrichment proposes similar if not more qualities than current aquatic enrichments commercially available. More specifically, its ease of usage, maintenance, and modular configuration options make it an ideal choice for Laboratory fish tanks. Results showed interaction on average up to 10.5 per 3 fish within a 30 second test interval versus 6.25 per 3 fish within 30 seconds interval for a mouse igloo. With the additional benefits highlighted in this study, the Aqualabyrinth proves to be an efficient and practical environmental enrichment option, pending collaboration with interested manufacturers.

Acoustic survey at Genova (Italy) Aquarium aiming at characterizing the acoustic of tropical marine environment

An acoustics survey has been performed at Genova (Italy) Aquarium aiming at characterizing the acoustic environment of tropical underwater habitats. Mid-term (5-7 days) and short-term measurements (10-20 min) within different fish tanks containing tropical habitats have been chosen for a preliminary analysis. Eco-acoustic indices and statistical-related acoustic indices have been applied to derive information on the population activity and determine the bio-acoustic richness. Such approach will be used to compare environments with different degree of disturbance and derive information on the environmental quality of both artificial and natural habitats

Comparative characteristics of the conditions for harvesting, transportation and spawning of pike perch in fish farms in Kazakhstan

A description of biotechnical methods of harvesting pike perch in natural reservoirs, methods of catching pike perch spawners, keeping in adaptation cages and transporting pike perch from fishing sites to the farm is given. Pike perch breeders were caught from the reservoirs with fixed and floating nets during the period: in the Kapshagai reservoir from 10 to 20 April; in the Syrdarya river — from April 20 to May 5. The adaptation was carried out in cages located in the coastal zone. Transportation to the fish farm was carried out in live fish tanks with a volume of 1 and 3 m³ with water aeration. The reproduction of pike perch was carried out in two fish farms of the Republic of Kazakhstan. The data on spawning of pike perch in two ways are given: in cages on nests; as well as the receipt of reproduction products by the factory method from “flowing” producers. In the first case, females and males were placed in cages in a ratio of 1:1 and 1:2; a spawning nest was installed in each cage and spawning was monitored. In the second case, from the “flowing” pike perch breeders ready for spawning, reproductive products (eggs and sperm) were obtained, fertilization and degluing were carried out with a suspension of white clay. The monitoring of hydrochemical indicators was constantly carried out, the dates of the beginning and end of spawning of pike perch were determined. The article presents the fish-breeding and biological characteristics of pike perch producers participating in spawning. The mass of spawned pike perch females in LLP “Halyk Balyk” ranged from 2 kg to 2.5 kg, males — 1.5–2.5 kg; females weighing 2.1–2.6 kg were used in the Republican State Enterprise “Kamyshly-Bashsky Fish Hatchery”; males — from 1.2 kg to 2.4 kg. Based on the results of the research, biotechnical standards were developed for the preparation of pike perch producers in water bodies, for transportation to fish farms, standards for spawning of pike perch in various ways.

The Cave of Adventure

Is it better to live in truth, or to live a happy lie? What if you could choose to forget past pain? In this work of choose your own adventure style philosophical short story of fiction, you are in the role of the main character, a female scientist studying the memory length of fish. While walking through the park you take an underground passage that has a new, and mysterious, offshoot passage to a cave full of fish tanks. There, you meet a child, the child you didn’t have, in the relationship that didn’t work out. The child takes you to another chamber with humans floating in water in stasis, living out their most blissful lives in their minds. You are given the choice, to join them in the tank to live out your remaining days as a successful scientist, with a loving husband, and a child or, to leave the cave, and enter the painful lonely life that lays ahead of you outside the cave.

Efficacy of some synthetic antibiotics on Streptococcus pneumoniae and Proteus mirabilis isolated from fish tanks

Effects of some synthetic antibiotics on Streptococcus pnemoniae and Proteus mirabilis isolated from cultured Clarias gariepinus, an important food fish raised in a concrete tank was carried out to ascertain their remedies on mortalities of the Clarias gariepinus adult fish. Streptococcus pnemoniae and Proteus mirabilis were isolated from the gill and skin of diseased fish and water samples and identified by standard microbiological methods.The bacteria isolates were tested for sensitivity on ten (10) antibiotics namely Amoxycillin, Gentamicin, Nitrofurantoin, Erythromycine, Augmentin, Tetracycline, Naladoxic acid, Cotrimoxazole, Cloxacillin and Ofloxacin. These organisms reacted differently to the different antibiotics that were used - Ofloxacine, Gentamycin and Erythromycine had highest zones of inhibition of 26mm and 26mm, 24mm and 19mm, 16mm and 17mm respectively around Streptococcus pnemoniae and Proteus mirabilis, but Naladoxic acid, Augmentin, Cloxacillin and Amoxycillin had no inhibition zones around both organisms. It is therefore recommended that Ofloxacine, Gentamycin and Erythromycine can be used to combat S. pnemoniae and P. mirabilis diseases in fish farms because of their high antibacterial potentials against the test organisms.