Biological Science: Research Developments and Innovations Vol. 6

Behavioral Responses of a Fresh Water Indian Air-breathing Fish Channa punctatus Exposed to Rogor in Laboratory Environments

Pintu Kumar Azad — 2026-11-04

Rogor (dimethoate), an organophosphate pesticide, can enter freshwater systems and affect non-target fish at sub-lethal concentrations. This laboratory study examined dose- and time-dependent behavioural responses of the freshwater air-breathing fish Channa punctatus following exposure to fractions of a predetermined 96-h LC₅₀ of 0.74 mL/20 L. Fish were assigned to a control group and three treatment groups receiving 1/5 LC₅₀ (0.148 mL/20 L), 1/3 LC₅₀ (0.247 mL/20 L), or 1/2 LC₅₀ (0.370 mL/20 L). Opercular movement, surfacing frequency, locomotor activity, feeding response, and stress-related abnormalities were assessed at 48, 72, and 96 h and at 10, 20, 30, and 40 days. Behavioural disturbances generally increased with concentration and exposure duration. Group B showed comparatively transient changes, whereas Groups C and D displayed more persistent increases in opercular movement and surfacing, reduced swimming performance, delayed feeding, lower food consumption, and higher stress-severity scores. By day 40, Group D showed a 62% reduction in mean swimming velocity and marked feeding suppression. Mortality was recorded in Groups C and D but not in the control or Group B. Principal component analysis indicated clear dose-related separation of behavioural responses, with sustained multi-endpoint impairment evident at higher exposures. Within the controlled laboratory conditions, these findings show that prolonged Rogor exposure was associated with progressive behavioural disruption in C. punctatus and support the use of behavioural endpoints alongside conventional toxicity measures.

Phytoplankton Community Structure as an Indicator of Eutrophication Risk in an Industrialized Tropical Bay: A Case in Bojonegara, Banten Bay, Indonesia

Endang S. Srimariana — 2026-11-04

Industrial and residential activities can influence nutrient availability and phytoplankton community structure in tropical coastal ecosystems. This study evaluated spatial and temporal variations in phytoplankton communities and their relationships with physicochemical conditions along the river–estuary–sea gradient of Bojonegara coastal waters, Banten Bay, Indonesia. Water and phytoplankton samples were collected from six stations representing riverine, estuarine, and marine environments during five sampling periods in 2023. Phytoplankton identification revealed 43 genera distributed among five classes: Bacillariophyceae, Chlorophyceae, Cyanophyceae, Dinophyceae, and Euglenophyceae. Bacillariophyceae and Cyanophyceae were the principal components of the phytoplankton community. Bacillariophyceae were generally associated with marine environments characterized by higher salinity and greater water transparency, whereas Cyanophyceae were more prominent in riverine and estuarine environments influenced by freshwater inputs. The Shannon–Wiener diversity index ranged from 0.979 to 1.769, indicating spatial differences in community diversity. Physicochemical measurements demonstrated variations in salinity, transparency, turbidity, nitrate, and phosphate concentrations among the sampling stations. Principal component analysis indicated that the first two components explained approximately 70.80% of the total variance. Bacillariophyceae and Dinophyceae were associated with higher salinity and transparency, while Chlorophyceae and Euglenophyceae showed associations with nutrient variables. These findings indicate that phytoplankton composition reflects environmental gradients in Bojonegara coastal waters and may provide complementary biological information for monitoring nutrient enrichment and potential eutrophication risk in industrially influenced tropical coastal environments.

Heterosis and Hybrid Breeding in Silkworms: Biological Basis and Commercial Applications

Priyangana Chetia — 2026-11-04

Hybrid breeding has shaped commercial production of mulberry silk, yet the connection between the phenotypic advantage of crosses, its underlying biology and its reliability under commercial rearing remains incompletely resolved. This critical narrative review evaluates heterosis in the domesticated mulberry silkworm, Bombyx mori, with attention to parental genetic resources, cross architecture, reciprocal and sex-specific effects, molecular mechanisms, stress adaptation, reeling quality and farm-level performance. Peer-reviewed genetic, genomic, transcriptomic, proteomic and breeding studies were appraised alongside evidence from controlled-rearing and farmer-field assessments published through 14 August 2026. Heterosis emerges as a trait-, cross- and environment-dependent outcome rather than an intrinsic property of any hybrid class. Evidence for favourable variation in cocoon and silk-related traits is substantial, but comparisons depend strongly on whether the reference is a parental mean, the superior parent or a commercially relevant check. Single, three-way and double crosses cannot be ranked universally, and general combining ability, genetic distance and marker associations are informative without being sufficient predictors of field performance. Molecular studies identify changes in metabolic regulation, protein synthesis and tissue-specific gene expression, with markedly different expression patterns among hybrid systems. These findings support biological plausibility but seldom identify causally necessary alleles or demonstrate independent field benefits. A smaller emerging evidence base links thermotolerant parentage and double-hybrid performance to cocoon and reeling outcomes under tropical conditions; replication, exposure measurement, seed quality and economic assessment are often inadequate for broad deployment claims. A proposed translation framework links verified parental identity, factorial testing, environmental robustness, independent reeling assessment and producer-level economics. Future progress requires multi-location randomised trials, validated genomic prediction and integrated assessments of resilience and raw-silk quality. Commercial usefulness should be judged by reproducible, risk-adjusted performance rather than heterosis percentages alone.

From Biodiversity to Bioactivity: A Decade of Prospecting for Plants with Insecticidal Potential

Silvana Aparecida de Souza — 2026-11-04

Plant extracts are a promising source of bioactive substances with potential for developing alternative strategies for managing insect pests. This chapter presents a ten-year trajectory of bioactive plant prospecting carried out within a research programme associated with the Federal University of Grande Dourados, using Plutella xylostella as the main biological model for evaluating extract activity. Twenty-five publications from 2016 to 2026 were reviewed, including 22 experimental studies on the pest, one study on selectivity to a parasitoid, one pollination study and one review on botanical insecticides and bees. Across this period, 33 plant taxa belonging to 13 families were investigated, considering different plant organs, extraction methods, solvents and concentrations. The studies showed that the bioactivity of the extracts can be expressed through different responses, including mortality and changes in development, reproduction, feeding and oviposition. Chemical characterisation revealed different classes of metabolites and, in some studies, individual compounds, although it is still not possible to attribute the observed activity to specific constituents. Taken together, the results show plant diversity to be a relevant source for prospecting substances with insecticidal potential and, at the same time, point to the steps needed to turn the identified bioactivity into technologies applicable to pest management, especially extract standardisation, agronomic validation and assessment of selectivity to non-target organisms.

Invasive Insect Pests in Global Agriculture: Biological Invasions, Climate Change and Biosecurity Challenges

Goutam Hosamani — 2026-11-04

Invasive insect pests pose a persistent threat to crop production, rural livelihoods and international plant-health systems. Their impacts emerge not from biological traits alone but from interactions among commodity movement, establishment dynamics, changing climatic suitability, agricultural landscapes and the capacity to detect and manage incursions. This critical narrative review integrates evidence on introduction pathways, population ecology, climate-mediated pest risks, contrasting invasion histories and biosecurity interventions. Peer-reviewed ecological, entomological, economic and policy research was critically assessed, with emphasis on the distinction between observations, experimental results, model-based projections and management proposals. International plant trade and other human-mediated movements create repeated opportunities for introduction, although interception records are imperfect proxies for propagule pressure. Temperature affects insect development and survival nonlinearly, while rainfall variability, landscape management, host availability and natural enemies can counteract or amplify warming effects. Studies of fall armyworm, tomato pinworm, brown marmorated stink bug, invasive fruit flies and spotted lanternfly illustrate why successful spread cannot be reduced to one universal invasion mechanism. Economic assessments establish substantial burdens but differ markedly in taxonomic scope, reporting completeness and treatment of counterfactual losses. Biosecurity evidence favours layered prevention, targeted surveillance, rapid diagnosis and timely response; nevertheless, the effectiveness of individual measures is often uncertain outside particular pathways and regions. Integrated pest management and biological control can reduce dependence on reactive insecticide use, but their long-term value depends on resistance evolution, non-target risks and institutional feasibility. The review argues for connecting pathway-level arrival data to mechanistic establishment models, field-validated climate scenarios, equitable economic assessments and explicit decision thresholds. A risk-adaptive biosecurity approach is warranted, provided uncertainties and trade-offs are represented transparently rather than masked by apparently precise global forecasts.