The demand for Striped Bass Morone saxatilis as food and sport fish has generated interest in developing effective transport and handling protocols. Studies have shown that anesthetics and elevated salinity can reduce transport stress in Striped Bass, but no studies have compared stress responses among strains or compared and combined treatments to maximize efficacy. In this study, 1‐h transport trials were conducted with subadults produced from wild‐caught (Florida strain) and domesticated Striped Bass. Fish were transported in freshwater (FW; 0‰) or brackish water (SW; 10‰) alone or containing either metomidate hydrochloride (hereafter, “metomidate”; 1 mg/L) or tricaine methanesulfonate (MS‐222; 25 mg/L). After transport, half the fish from each treatment were sampled for cortisol or stocked in a freshwater recirculating system to monitor their health and behavior for 7 d. In preanesthesia trials, Florida‐strain fish were netted and transferred to baths containing a single anesthetic (induction doses; 5‐mg/L metomidate or 150‐mg/L MS‐222), observed for nociception and recovery, and bled 1 h after anesthesia for cortisol analysis. Results from this traditional approach were compared to results for fish that were first exposed to low anesthetic doses (1‐mg/L metomidate or 25‐mg/L MS‐222) added directly to the culture tank prior to netting and then were transferred to baths containing induction doses of the same anesthetic. In transport studies, cortisol was elevated in the MS‐222 and FW treatment groups compared to the metomidate and SW treatment groups, respectively. Strain, feed consumption, and health were not correlated with cortisol measured following the transport stressor. In the preanesthesia study, metomidate blocked cortisol synthesis if added prior to or following handling, while MS‐222 blocked nociception.

Aspergillus flavus infects peanuts and produces a mycotoxin called aflatoxin, a potent human carcinogen. In infected peanuts, it can also affect peanut seed quality by causing seed rot and reducing seed viability, resulting in low germination. In 2020, peanut seeds in Georgia had lower than expected germination and a high frequency of A. flavus contamination. A total of 76 Aspergillus isolates were collected from seven seed lots and their identity and in vitro reaction to QoI (quinone outside inhibitor) fungicide (azoxystrobin) were studied. The isolates were confirmed as A. flavus by morphological characteristics and a PCR (polymerase chain reaction)-based method using species-specific primers. In vitro, these isolates were tested for sensitivity to azoxystrobin. The mean EC50 values ranged from 0.12 to 297.22 μg/mL, suggesting that some isolates were resistant or tolerate to this fungicide. The sequences of cytochrome b gene from these isolates were compared and a single nucleotide mutation (36.8% isolates) was found as Cyt B G143A, which was associated with the total resistance to the QoIs. Another single mutation (15.8% isolates) was also observed as Cyt B F129L, which had been documented for QoI resistance. Therefore, a new major single mutation was detected in the A. flavus natural population in this study, and it might explain the cause of the bad seed quality in 2020. The high frequency of this new single nucleotide mutation exists in the natural population of A. flavus and results in the ineffectiveness of using azoxystrobin seed treatment. New seed treatment fungicides are needed.

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Understanding patterns in trace element concentrations and water quality within river systems provides a foundation to evaluate retrospective movements and habitat use of fish. Because trace elements are incorporated into calcified structures of fishes relative to water concentrations, baseline maps have application for fisheries management, including for rare species such as sturgeons. Therefore, trace elements [strontium (Sr), barium (Ba), manganese (Mn), zinc (Zn), and magnesium (Mg)], strontium isotopes ( 87 Sr/ 86 Sr), dissolved oxygen and salinity were measured in the Pearl River and Lake Pontchartrain watersheds, within Mississippi and Louisiana, USA for application in assessing riverine use by Gulf Sturgeon Acipenser oxyrinchus desotoi. Water samples were collected during the summerfall period when juvenile Gulf Sturgeon were anticipated to be present and analyzed by solution and multi-collector inductively coupled plasma mass spectrometry. Trace element to calcium (Ca) ratios in Sr, Ba, Zn, and Mg were distinguishable between the upper Pearl River and the Bogue Chitto River tributary, and the upper Pearl River and lower Pearl River. For most trace elements and 87 Sr/ 86 Sr, there was a gradual increase from upper river regions to lower river regions, and large differences between freshwater and saline areas. Lake Pontchartrain watershed rivers were not easily differentiated, but regions of low dissolved oxygen concentrations in the lower reaches suggest available Gulf Sturgeon habitat may be seasonally limited. Therefore, maps of water microchemistry in the Pearl River watershed allow for retrospective analyses of fish watershed use.

The trematode Bolbophorus damnificus (Digenea: Bolbophoridae) has caused significant economic losses since the late 1990s, with deleterious effects on production efficiency in farm‐raised catfish. Previous work has demonstrated that even mild outbreaks, which may go unnoticed by producers, can result in over 60% reduction in net economic returns. Although transmission rates in Channel Catfish Ictalurus punctatus and hybrid catfish (Channel Catfish × Blue Catfish Ictalurus furcatus) are similar in controlled studies, anecdotal industry reports imply that the impacts of B. damnificus on hybrid catfish are less severe. In this study, mortality in juvenile Channel and hybrid catfish exposed to B. damnificus was evaluated in two discrete, replicated infectivity challenges. Mortality curves in Channel and hybrid catfish were consistent with trends previously established for B. damnificus in Channel Catfish, although in both challenges cumulative mortality was significantly lower in hybrids. All exposed fish presented clinical signs consistent with B. damnificus infection—namely lethargy, exophthalmia, distended abdomens, and metacercariae grossly visible below the skin. No mortality occurred and no parasites were observed in control fish. The biological and economic implications of these findings on catfish production are unknown but suggest that hybrid catfish are less susceptible to the deleterious effects and reduced productivity elicited by B. damnificus in Channel Catfish.