Qualified presumption of safety (QPS) was developed to provide a generic safety evaluation for biological agents to support EFSA's Scientific Panels. The taxonomic identity, body of knowledge, safety concerns and antimicrobial resistance are assessed. Safety concerns identified for a taxonomic unit (TU) are where possible to be confirmed at strain or product level, reflected by 'qualifications'. No new information was found that would change the previously recommended QPS TUs and their qualifications. The list of microorganisms notified to EFSA was updated with 54 biological agents, received between April and September 2019; 23 already had QPS status, 14 were excluded from the QPS exercise (7 filamentous fungi, 6 Escherichia coli, Sphingomonas paucimobilis which was already evaluated). Seventeen, corresponding to 16 TUs, were evaluated for possible QPS status, fourteen of these for the first time, and Protaminobacter rubrum, evaluated previously, was excluded because it is not a valid species. Eight TUs are recommended for QPS status. Lactobacillus parafarraginis and Zygosaccharomyces rouxii are recommended to be included in the QPS list. Parageobacillus thermoglucosidasius and Paenibacillus illinoisensis can be recommended for the QPS list with the qualification 'for production purposes only' and absence of toxigenic potential. Bacillus velezensis can be recommended for the QPS list with the qualification 'absence of toxigenic potential and the absence of aminoglycoside production ability'. Cupriavidus necator, Aurantiochytrium limacinum and Tetraselmis chuii can be recommended for the QPS list with the qualification 'production purposes only'. Pantoea ananatis is not recommended for the QPS list due to lack of body of knowledge in relation to its pathogenicity potential for plants. Corynebacterium stationis, Hamamotoa singularis, Rhodococcus aetherivorans and Rhodococcus ruber cannot be recommended for the QPS list due to lack of body of knowledge. Kodamaea ohmeri cannot be recommended for the QPS list due to safety concerns.

https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2020.5965

Update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA 13: suitability of taxonomic units notified to EFSA until September 2020.

Structural adequacy of the digestive tract supports dual feeding habit in catfish Pachypterus khavalchor (Siluriformes: Horabagridae)

The Western Ghats of India, one of the global biodiversity hotspots and freshwater eco-regions, harbors several fish species which not just form the important part of the world’s freshwater biodiversity yet in addition are the vital segment of livelihood of the neighborhood population. The rate of fish decline in the Western Ghats is alarming. The absence of organized study and data scarcity on basic biology and life history traits of several species could be one reason behind the decline, and thus it is difficult to execute conservation action/s. This is especially true, particularly for data-deficient species for which definite data related to distribution, population size, and trend is not available. The present study deals with the detailed investigation of population dynamics of catfish species, Pachypterus khavalchor, which is data-deficient species inhabiting the Western Ghats of India and forms an important component of freshwater inland fishery, providing nutritional and financial security to the local community. Specimens for the present study were collected monthly for a period of 1 year from the River Panchaganga and length–frequency data were analyzed using FiSAT II software. Length–weight analysis of pooled (male + female) data suggested the fish exhibited higher exponent than expected under isometry, indicating the positive allometric growth of P. khavalchor in the Panchaganga River. The asymptotic length (L∞) and the growth rate (K) were estimated as 149.63 mm and 0.71 year−1 respectively. Potential longevity (tmax) and length at first capture (Lc) were estimated as 4.22 years and 73 mm respectively. The total (Z), natural (M), and fishing mortality (F) were estimated as 2.23 year−1, 0.88 year−1, and 1.35 year−1 respectively. The current exploitation rate (Ecur = 0.60) was found to be almost 90% that gives the maximum relative yield per recruit (Emax = 0.67). Recruitment pattern revealed two peaks, suggesting the fish have two spawning bouts each year. The stock of P. khavalchor in the Panchaganga River may be in near full exploitation under the current harvesting strategy, with a high chance of recruitment failure in the future. Additional studies on the reproductive biology of P. khavalchor would be particularly welcome for the imposition of the seasonal closure for effective conservation of stock.

/pdf/assessing-the-sustainability-of-lepidophagous-catfish-1djv8y75ea.pdf

Assessing the sustainability of lepidophagous catfish, Pachypterus khavalchor (Kulkarni, 1952), from a tropical river Panchaganga, Maharashtra, India

The effect of the environment on fitness in natural populations is a fundamental question in evolutionary biology. However, most empirical field studies of fitness do not experimentally manipulate phenotypes or environmental conditions and rarely investigate more than a single species or population. Thus, the relative importance of the competitive environment versus intrinsic organismal performance in shaping the location, height, and fluidity of fitness peaks on the adaptive landscape remains largely unknown. We experimentally tested the effect of competitive environment on a multi-peak fitness landscape driving a microendemic adaptive radiation of generalist and trophic specialist pupfishes on San Salvador Island, Bahamas. We manipulated phenotypes, by generating lab-reared hybrid crosses, and competitive environment, by altering the frequency of rare phenotypes within field enclosures in their natural hypersaline lake environments on San Salvador. We tracked the growth and survival of 2,611 F4/F5 hybrids for 3 to 11 months in high- and low-frequency treatments replicated across two lake populations. We found strong evidence for frequency-dependent growth rates within and between enclosures, but no evidence for frequency-dependent survival differences. However, both fitness proxies supported a complex fitness landscape isolating generalist phenotypes on a local fitness peak separated by a small fitness valley from a higher fitness peak for molluscivores and a large fitness valley isolating the scale-eating phenotype in all trait dimensions. The striking consistency of this multi-peak fitness landscape across competitive environments, multivariate trait axes, and a previous field experiment provides experimental evidence for stasis, possibly due to fixed biomechanical constraints on organismal performance. These results challenge existing theory and highlight the interplay of organism and environment underlying the static and dynamic features of fitness landscapes.

https://www.biorxiv.org/content/biorxiv/early/2019/09/06/756908.full.pdf

Surprising spatiotemporal stability and frequency-independence across multiple fitness peaks driving adaptive radiation in the wild

Pachypterus khavalchor (Kulkarni, 1952) is a rarely studied but highly exploited catfish species inhabiting the Krishna River system of India. A total of 427 fishes were collected monthly from the Panchaganga River to study its reproductive characteristics. Samples were analysed for length-weight morphometry, sexual dimorphism, gonad weight, and maturity status. Gonadosomatic Index (GSI), hepato-somatic Index (HSI), and stomach fullness index (SFI) were estimated to assess reproductive periodicity and its correlation with the fish condition and energy dynamics. Males had a cone-like genital papilla as a sexually dimorphic character. The male-female ratio was 1:1.02 (not different from 1:1) and females were comparatively larger than the males. Males matured at smaller sizes (7.3 cm) as compared to females (8.9 cm). The absolute fecundity varied from 932 to 24642 eggs.fish-1 while the relative fecundity ranged from 226 to 723 eggs.g-1 of body weight. Regression analysis revealed a significant relationship between fecundity and ovary weight (r = 0.970). The GSI indicated that the breeding season for P. khavalchor is from April to August. The HSI and SFI showed that both males and females have similar seasonal reproductive patterns and feeding behaviour. Due to limited knowledge of its biology, its rare occurrence, and a highly fragmented population, the present study is likely to be useful in designing sustainable management and conservation plans for P. khavalchor.

/pdf/the-reproductive-biology-of-pachypterus-khavalchor-kulkarni-1n7dn9k0w8.pdf

Sushant S. Navarange

Papers

Interplay between behavior, morphology and physiology supports lepidophagy in the catfish Pachypterus khavalchor (Siluriformes: Horabagridae).