Hyphessobrycon Herbertaxelrodi Research Articles

Photosynthetic Bacteria as an Alternative Wastewater Treatment in Freshwater Aquarium Fish Set Up

Waste produced from aquaculture ultimately hampered the water quality and growth performance of species cultured. Therefore, the potential exploitation of photosynthetic bacteria (PSB) from aquaculture waste was investigated to treat the wastewater in the fish culture. In this study, the wastewater was collected from a fishpond and cultured in sunlight-exposed sterile bottles for 14 days. In the water additive experiment, five treatments (in a 30 cm3 aquarium) were prepared namely cultured PSB (T1), aquatic plant hornwort (T2), aquatic plant salvinia (T3), positive control (P), and negative control (N). Five individuals of Hyphessobrycon herbertaxelrodi (2.5±0.5 cm length) were placed in each treatment and reared for 30 days. Meanwhile, for the wastewater treatment, four treatments (in a 30 cm3 aquarium) were prepared namely wastewater from the hatchery fishpond (S1), wastewater from the hatchery fish tank (S2), positive control (P), and negative control (N). The results obtained indicate that T1 treatment significantly improved and maintained the water quality as compared to other treatments. The results showed the amount of ammonia and nitrite in S1 and S2 supplied with T1 for 30 days gradually decreased from day 1 until day 18. While zero amount of ammonia and nitrate was acquired from day 21 until day 30 of the wastewater experiment. The treatment with PSB showcased the bacteria's ability to utilize and absorb nutrients, thereby maintaining and improving water quality. The potential use of beneficial bacteria in the culture system can accelerate the nitrogen cycle for a sustainable way of wastewater management.

Motion leadership and local interaction in two species of freshwater fish (Danio rerio and Hyphessobrycon herbertaxelrodi).

The authors studied momentary motion leadership in small groups of black neon tetra (Hyphessobrycon herbertaxelrodi) and zebrafish (Danio rerio), its relationship with local interaction parameters, such as the acceleration and turning angle of the individuals, and the relative locations of the individuals within the group. The purpose was to know whether leadership tended to be monopolised by certain individuals or whether it was equitably shared between them and if there were differences in leadership sharing between these two species, which are known to have different degrees of cohesion and polarisation. The authors filmed groups of two, three, four and eight fishes of each species and tracked their individual motion by image analysis and trajectory extraction. In both species, motion leadership was not monopolized but egalitarian and very short lived, with leadership shifts distributed randomly over time. The duration of leadership episodes decreased as group size increased and was longer in black neon tetra than in zebrafish. Momentary leaders did not tend to be in the front positions, but closer to the centre of the group. Acceleration and turning angle were more extreme in zebrafish than in black neon tetra and in the momentary leaders than the followers in both species. In general, these differences between species and between leaders/followers were qualitatively similar with some differences in detail, indicating that the relationship between motion leadership and local interaction parameters is likely to conform to a general physical law.

Embryonic Development of Black Neon Tetra Hyphessobrycon herbertaxelrodi Géry, 1961

The current study described the embryonic development stages of black neon tetra (Hyphessobrycon herbertaxelrodi), an economic ornamental fish. We characterized the stages of the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching occurring during embryogenesis, which emphasizes changing spectrum of the main development processes from fertilization to incubation. The findings were put forth and photographed by examining live embryos under microscopy. Embryonic development of black neon tetra concluded at 24 ± 0.5°C water temperature at 20-21 hours. The first embryonic division occurs within the first 43 minutes after fertilization, and the process goes on to blastula at 02 hours and 28 minutes. The gastrula stage began at 02.57 hours, while 6 somite segmentation stages were observed to occur at 08.14 hours. Following the pharyngula stage seen between 17 to 20 hours, the hatching occurred at 20-21hours. The results of this study can provide significant benefits to professional breeders in the aquaculture of black neon tetra and other ornamental fish species.

Mitochondrial genomes of four American characins and phylogenetic relationships within the family Characidae (Teleostei: Characiformes).

Mitochondrial genome sequencing has become widely used in numerous fields, including systematics, phylogeny, and evolutionary genomics. To elucidate phylogenetic relationships among members of the family Characidae, we sequenced the mitogenomes of four species within this family, namely, Aphyocharax rathbuni, Hyphessobrycon herbertaxelrodi, Hyphessobrycon megalopterus, and Prionobrama filigera. The mitogenomes were found to be 16,678-16,841bp and encode 37 typical mitochondrial genes (13 protein-coding, 2 ribosomal RNA, and 22 transfer RNA genes). Gene arrangements in the studied species are consistent with those in the inferred ancestral fish. Most protein-coding genes in these mitogenomes have typical ATN start codons and TAR or an incomplete stop codon T-. Phylogenetic relationships based on Bayesian inference and maximum-likelihood methods indicated that A. rathbuni, H. herbertaxelrodi, H. megalopterus, and P. filigera belong to the Characidae family. Of the 15 Characidae species studied, three pairs were of the same genus, but the results for only one pair were well supported. This phylogenetic classification is inconsistent with those described in previous morphological and taxonomic studies on this family. Thus, systematic classification of the Characidae requires further examination. Our findings yield new mitogenomic data that will provide a basis for future phylogenetic and taxonomic studies.

Characterization of the complete mitochondrial genome of Hyphessobrycon herbertaxelrodi (Characiformes, Characidae) and phylogenetic studies of Characiformes

In this study, the complete mitochondrial genome of Hyphessobrycon herbertaxelrodi is presented, and we also discussed its mitochondrial characteristics. The full length of the mitochondrial genome was 17,417 bp, including 13 protein coding genes (PCGs), 2 ribosomal RNAs (12S and 16S), 22 transfer RNA genes, 1 non-coding control region (D-loop), and 1 origin of replication on the light-strand. The total nucleotide composition of mitochondrial DNA was 29.76%A, 29.88%T, 25.35%C, 15.01%G, and AT was 59.64%. The phylogenetic tree suggested that H. herbertaxelrodi shared the most recent common ancestor with Astyanax giton, Grundulus bogotensis, Astyanax paranae, and Oligosarcus argenteus.

Local interaction rules and collective motion in black neon tetra (Hyphessobrycon herbertaxelrodi) and zebrafish (Danio rerio).

We explored the local motion rules used by interacting individuals in small groups of black neon tetra (Hyphessobrycon herbertaxelrodi) and zebrafish (Danio rerio) to ascertain if and how these rules underlie the fishes' global collective coordinated motion. As these 2 species show very different styles of collective motion in terms of cohesion and polarization, we expected to find differences in their individual behavioral rules. We recorded groups of 2, 3, 4, and 8 fish of each species; tracked their individual trajectories; and studied how their individual turning angles and accelerations varied as a function of heading differences, distances, and relative angles to their neighbors. We found that black neon tetra and zebrafish differed in terms of their preferential positions with respect to their neighbors, the magnitude of turning angles and accelerations, and the way these angles and accelerations are modulated by both the distance from neighbors (thus suggesting a "repulsion" zone in black neon tetra but not in zebrafish) and the heading difference and relative angle to neighbors. Our results enable us to infer that, in black neon tetra, avoiding excessive proximity and collision takes priority over cohesion, and cohesion takes priority over polarization. This provides evidence that rules are similar in species of very different genera and that differences are a matter of degree. Our results also provide substantial empirical evidence to support the theoretical assumptions made in agent-based models that simulate coordinated collective motion in many different animal species. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Leadership and collective motion in black neon tetra schools: does the task matter?

ABSTRACTMany fish schools are regarded as leaderless, where any individual can guide the direction of group motion at any given moment. We conditioned a fish school of black neon tetra (Hyphessobrycon herbertaxelrodi) to find food in aparticular location, while another group swam freely with no particular goal. Groups were composed of similar individuals in terms of body size, task knowledge and hunger level. Our hypothesis was that leadership would be less stable when fish were conditioned than when they were not. Although stability tended to be greater in the conditioned group, the hypothesis was not confirmed, as both groups showed asimilar degree of leadership stability. Leadership was not entirely random and some individuals took the lead more often than others. Leaders tended to be at the front of the school and their tendency to lead was loosely related to higher swimming speeds, and not related to task knowledge.

Ionoregulatory Characteristics of Non-Rio Negro Characiforms and Cichlids.

We examined ionoregulatory characteristics of two species of characiform fish and two species of cichlids that are not native to the Rio Negro, an extremely ion-poor, acidic tributary of the Amazon River, in order to gain insight into the origin of the specializations possessed by Rio Negro fish. The two characiform species examined, Congo tetras (Phenacogrammus interruptus) and black neon tetras (Hyphessobrycon herbertaxelrodi), had high-affinity/high-capacity transporters that produce high rates of uptake in dilute water. Na+ uptake for both was pH insensitive (down to pH 3.5). Exposure to 100 μmol L-1 phenamil had no effect on Na+ uptake in either species, while exposure to 1 mmol L-1 NH4Cl- (high external ammonia [HEA]) slightly stimulated Na+ uptake in Congo tetras. Exposure to "Na+-free" water significantly inhibited Na+ uptake (by 65%-85%) but had no effect on net ammonia flux. The two cichlid species examined, convict cichlids (Amatitlania siquia) and red point cichlids (Archocentrus sp.), had high-affinity but low-capacity transporters that yield low rates of uptake in dilute media. Sodium transport was pH sensitive and completely inhibited at pH 3.5. Phenamil exposure inhibited Na+ uptake by 60% in convict cichlids but had no effect on red point cichlids, and exposure to HEA reduced Na+ uptake in both species by 70%-85%. Exposure to "Na+-free" water reduced Na+ uptake by 80%-85%, and in convict cichlids it also reduced net ammonia flux by about 50%. The ionoregulatory characteristics described for both groups are strikingly similar to those for Rio Negro species, and we suggest that they may be ancestral physiological traits for these two groups. Further, if this is the case, it seems likely that these traits existed before the Rio Negro and may explain the great success of these species-rich groups in colonizing the river despite its challenging chemistry.

Differences in shoaling behavior in two species of freshwater fish (Danio rerio and Hyphessobrycon herbertaxelrodi).

Fish can gain significant adaptive advantages when living in a group and they exhibit a wide variety of types of collective motion. The scientific literature recognizes 2 main patterns: shoals (aggregations of individuals that remain close to each other), and schools (aggregations of aligned, or polarized, individuals). We analyzed the collective motion of 2 social fish species, zebrafish (Danio rerio) and black neon tetra (Hyphessobrycon herbertaxelrodi), and compared their patterns of movement and the effect of group size and environmental constraints such as water column height and tank geometry on the collective motion of both species. We recorded the movement of groups of fish (n = 10 and n = 20) using 2 tank geometries: a rectangular shape and a rectangular shape with rounded corners; and we also manipulated the water column height (15 and 25 cm). We extracted the individual fish trajectories and calculated indices of cohesion, coordination, group density and group shape. The results showed that the 2 species had different types of collective motion: the zebrafish's global motion matched that of a shoal, while the black neon tetra's motion matched that of a school. Indirect evidence indicated that the 2 species tended to occupy the vertical space differently while swimming in a group. Finally, we found that tank geometry did not affect group polarization, whereas group size had an effect on black neon tetra density, which was higher in small group sizes than in large ones. (PsycINFO Database Record

A method for resolving occlusions when multitracking individuals in a shoal.

Studying the collective behavior of fishes often requires tracking a great number of individuals. When many fishes move together, it is common for individuals to move so close to each other that some fishes superimpose themselves on others during one or several units of time, which impacts on tracking accuracy (i.e., loss of fish trajectories, interchange of fish identities). Type 1 occlusions arise when two fishes swim so near each other that they look like one long fish, whereas type 2 occlusions occur when the fishes' trajectories cross to create a T- or X-shaped individual. We propose an image processing method for resolving these types of occlusions when multitracking shoals in two dimensions. We assessed processing effectiveness after videorecording shoals of 20 and 40 individuals of two species that exhibit different shoal styles: zebrafish (Danio rerio) and black neon tetras (Hyphessobrycon herbertaxelrodi). Results show that, although the number of occlusions depended on both the number of individuals and the species, the method is able to effectively resolve a great deal of occlusions, irrespective of the species and the number of individuals. It also produces images that can be used in a multitracking system to detect individual fish trajectories. Compared to other methods, our approach makes it possible to study shoals with water depths similar to those seen in the natural conditions of the two species studied.

Visualization of a fish wake using tobacco mosaic virus

TMV and viewed through a crossedpolarizer. Flow disturbances cause the rod-shaped TMV toorient along flow lines and so differentially refract incominglight to produce bright spots in regions of strong shear. Theviral solution is invisible to the naked eye and only becomesapparent under examination through a polarizer. An attrac-tive feature of this technique is that it is harmless to fish,providing a safe alternative for visualizing their wakes.The black neon tetra Fig. 1 of body length 3.6 cmmaintains a steady position by flicking its fins and creatingvortices. The fish’s breathing is marked by a glowing whiteregion created by the suction into its mouth. In Fig. 2, thefish swims upward generating a conical wake whose breadthbrakes by extending its pectoral fins and blowing a vortexring from its mouth.Polarized light can also be used to illuminate a suffi-ciently low dilution of Kalliroscope Fig. 3 that it is invis-ible to the naked eye and benign to fish.

Use of decapsulated Artemia cysts in ornamental fish culture

Two series of feeding experiments were conducted to study the feasibility of using decapsulated Artemia cysts for direct feeding to ornamental fish. The first series evaluated the dietary values of the dried and the brine decapsulated Artemia cysts against two conventional live feeds, Artemia nauplii and Moina for adults and fry of the guppy, Poecilia reticulata Peters. In the second series, brine cysts were used for feeding to fry of four other important ornamental fish species, viz. platy, Xiphophorus maculatus (Gunther), swordtail, X. helleri (Heckel), molly, P. sphenops Cuvier & Valenciennes and black neon tetra, Hyphessobrycon herbertaxelrodi Gery, and the results were compared with those fed Moina. Evaluation of the performance of the fish fed the various diets was based on stress resistance, growth and survival of the fish. Our findings indicated that decapsulated cysts could be used as a substitute for Artemia nauplii or Moina in freshwater ornamental fish culture. Apart from being a hygienic off-the-shelf feed, the direct use of the cysts also signifies a new area of application for low-hatch cysts in the ornamental fish industry, with concomitant saving in feed costs.

The control of ichthyophthiriasis by a medicated food containing quinine: efficacy tests and ultrastructure investigations.

The present report demonstrates that a medicated food containing quinine kills the skin-inhabiting trophozoite stage of Ichthyophthirius multifiliis in ornamental fish. Artificially infected swordtails. (Xiphophorus helleri), black mollies (Poecilia sphenops), and black neons (Hyphessobrycon herbertaxelrodi) were used in the trials. The fish were maintained in groups of 10 or 20 inside aquaria (20 or 60 l) at 25 degrees C. Ultrastructure investigations by means of transmission electron microscopy revealed clear deleterious effects of quinine on the trophozoite stages. Following the initial application the outer limiting membrane of the trophozoite was broken at places. Within the nephridial plasma the plasma bridges were broken in part. After 2 days of treatment the lumen of the alveolar sac became enlarged. The food vacuoles in treated trophozoites were more electron-dense than those in the untreated controls. Numerous lipid droplets were found close to the vacuoles. The degree of damage in the nephridial plasma was intensified. When feeding was prolonged for 3 or more days, all kinds of damage became more extensive as seen in the trophozoites after 1 or 2 days of treatment. In addition food vacuoles in the final stages of digestion were no longer detectable. In long-term feeding tests, when typical ornamental fish species were fed three times daily ad libitum with the medicated food over a 12-week period, the animals showed no adverse clinical symptom. From the toxicological as well as the ecological and economical point of view the feeding of flakes containing quinine has considerable advantages as compared with conventional bath treatment.