Petromyzon Research Articles

Research on Sex-Ratio-Variable Sea Lamprey Populations Based on Logistic and Lotka-Volterra Models

The increasing prevalence of invasive species like the sea lamprey poses significant challenges to aquatic ecosystems. This study explores the potential ecological impacts of the sea lamprey’s unique ability to alter its sex ratio. This paper developed mathematical models based on Logistic and Lotka-Volterra equations to simulate the impact of sex ratio changes on population dynamics, genetic diversity, and ecosystem stability. In this model, the carrying capacity of the sea lamprey's environment is linked to its food supply. According to the model developed in this paper, sea lampreys are more likely to develop into males when food is scarce, which is consistent with observed behavior. Additionally, the findings suggest that the sea lamprey's mechanism for adjusting its sex ratio provides it with a significant advantage over other species, both in terms of competition and predation. The findings highlight the dual role of sex ratio variability in enhancing population resilience while potentially reducing genetic diversity, providing insights into managing invasive species and preserving biodiversity.

Biomass prediction of sea lamprey population based on dynamic feature matrix composite differential equation system

This article presents a mathematical model to predict sea lamprey biomass, addressing the species' impact on the Great Lakes fishery. The model, comprising a Dynamic Age Pyramid and a Multi-species Lotka-Volterra system, captures the complex life stages and behaviors of sea lampreys. It simulates their diet, habits, and growth parameters across different ages, considering their adaptive sex ratio variation. Key findings include the model's ability to dynamically update sea lamprey population characteristics annually in response to environmental changes. Simulations show that populations with dynamic sex ratios reach equilibrium faster, with an increasing female proportion over time in resource-rich environments. However, these populations exhibit less resilience to rapid environmental shifts compared to those with stable sex ratios. The study concludes that the model offers a valuable tool for understanding complex organism-environment interactions and enhances traditional ecological models by providing a dynamic, biologically meaningful population feature matrix. This innovation aids in managing invasive species like sea lampreys without harming native ecosystems.

Fish Species Spinal Cord Injury Models Utility for Research: A Systematic Review of Methodologies and Outcomes

Context: Spinal cord injury (SCI) is a devastating condition that results in severe disability and significant comorbidities. The complex pathophysiology of SCI repair and difficulties understanding neural regeneration are treatment challenges. Objectives: The aim of this study is to systematically review the diverse applications of various fish species as models for SCI research. Evidence Acquisition: PRISMA guidelines were used to review observational and interventional studies that utilized fish species as SCI models, published from inception to July 2023. Two independent reviewers screened and performed the data extraction. One independent reviewer assessed the risk of bias for the included studies. Results: Five thousand six hundred and thirty-three records were reviewed, and 144 met the inclusion criteria and were categorized by fish species. The majority of studies employed complete transection injuries, with the remainder being crush injuries, laser injuries, electro-ablations, and demyelination with substances. Zebrafish (Danio rerio) were most commonly utilized 102/144 (71%), primarily with larval models. Other models included Lamprey (Petromyzon marinus and Lethenteron reissneri); Goldfish (Carassius auratus); European eel (Anguilla Anguilla); Knifefish (Apteronotus leptorhynchus and Apteronotus albifrons); Sailfin Molly (Poecilia latipinna); and African turquoise killifish (Nothobranchius furzeri). Conclusions: This systematic review highlights that fish models, particularly zebrafish, goldfish, and European eels, are important models for further defining SCI pathophysiology and regenerative processes. These models provide a less complex model to gain insights into apoptosis and glial networks.

Peering into the eye of the sea lamprey: what can stable isotopes in lamprey eye lenses reveal about their life history?

Peering into the eye of the sea lamprey: what can stable isotopes in lamprey eye lenses reveal about their life history?

Interaction model between sea lampreys and ecosystem based on Logistics model

Interaction model between sea lampreys and ecosystem based on Logistics model

Olfactory Projections to Locomotor Control Centers in the Sea Lamprey.

Although olfaction is well known to guide animal behavior, the neural circuits underlying the motor responses elicited by olfactory inputs are poorly understood. In the sea lamprey, anatomical evidence shows that olfactory inputs project to the posterior tuberculum (PT), a structure containing dopaminergic (DA) neurons homologous to the mammalian ventral tegmental area and the substantia nigra pars compacta. Olfactory inputs travel directly from the medial olfactory bulb (medOB) or indirectly through the main olfactory bulb and the lateral pallium (LPal). Here, we characterized the transmission of olfactory inputs to the PT in the sea lamprey, Petromyzon marinus. Abundant projections from the medOB were observed close to DA neurons of the PT. Moreover, electrophysiological experiments revealed that PT neurons are activated by both the medOB and LPal, and calcium imaging indicated that the olfactory signal is then relayed to the mesencephalic locomotor region to initiate locomotion. In semi-intact preparations, stimulation of the medOB and LPal induced locomotion that was tightly associated with neural activity in the PT. Moreover, PT neurons were active throughout spontaneously occurring locomotor bouts. Altogether, our observations suggest that the medOB and LPal convey olfactory inputs to DA neurons of the PT, which in turn activate the brainstem motor command system to elicit locomotion.

Lake Superior fish community and fisheries, 2001–2022: An era of stability

Lake Superior is the least anthropogenically impacted of the Laurentian Great Lakes ecosystems, yet dramatic changes to the fish community are evident. Previous published works chronicled those changes and the efforts to rehabilitate the fish community through the year 2000. Here, we review through the year 2022, where post-rehabilitation stability was driven by lean lake trout (Salvelinus namaycush namaycush) as the most abundant piscivore in nearshore waters, siscowet lake trout (Salvelinus namaycush siscowet) as the most abundant piscivore in offshore waters, and a healthy, intact assemblage of native prey species, which created ecological redundancies and helped stabilize the food web. Stocking of non-native salmonines was reduced 74%, and populations of Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) were maintained through natural reproduction. Despite reduced stocking, yield from recreational fisheries was stable. Likewise, developments in population modeling led to evaluations and refinement of management strategies that helped create stability for lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) fisheries. With lake trout rehabilitation achieved, focus shifted toward rehabilitation of native brook trout (Salvelinus fontinalis), lake sturgeon (Acipenser fulvescens), and walleye (Sander vitreus). Despite continued control efforts, sea lamprey (Petromyzon marinus) abundance increased considerably, and estimates of fish killed by lampreys averaged 2.65 million kg annually. Environmental changes have benefited sea lampreys and fostered thermal habitats more suitable to non-native organisms, posing new challenges for managers and researchers. Nevertheless, the post-rehabilitation stability in the contemporary fish community will help provide resilience to future perturbations in the ecosystem.

Predicting the sea lamprey population dynamic and ecosystem stability based on sex ratio corrected logistic model

Predicting the sea lamprey population dynamic and ecosystem stability based on sex ratio corrected logistic model

High throughput long-read sequencing of circulating lymphocytes of the evolutionarily distant sea lamprey reveals diversity and common elements of the variable lymphocyte receptor B (VLRB) repertoire.

The leucine-rich repeat-based variable lymphocyte receptor B (VLRB) antibody system of jawless vertebrates is capable of generating an antibody repertoire equal to or exceeding the diversity of antibody repertoires of jawed vertebrates. Unlike immunoglobulin-based immune repertoires, the VLRB repertoire diversity is characterized by variable lengths of VLRB encoding transcripts, rendering conventional immunoreceptor repertoire sequencing approaches unsuitable for VLRB repertoire sequencing. Here we demonstrate that long-read single-molecule real-time (SMRT) sequencing (PacBio) approaches permit the efficient large-scale assessment of the VLRB repertoire. We present a computational pipeline for sequence data processing and provide the first repertoire-based analysis of VLRB protein characteristics including properties of its subunits and regions of diversity within each structural leucine-rich repeat subunit. Our study provides a template to explore changes in the VLRB repertoire during immune responses and to establish large scale VLRB repertoire databases for computational approaches aimed at isolating monoclonal VLRB reagents for biomedical research and clinical applications.

Acute toxicity of lampricides to non-target species of concern in the Lake Champlain watershed

Previous research evaluated the toxicity of the lampricide 4-nitro-3-(trifluoromethyl)phenol (TFM) and the combination of TFM with 1 % niclosamide (TFM:1%Nic) to multiple non-target species in the Laurentian Great Lakes. However, few toxicity studies have been conducted for species of concern in Lake Champlain (NY and VT). We conducted 12-hour flow-through toxicity tests with 4 species of native mussels, 6 species of fish, and 1 amphibian species. All tests included exposure of invasive larval Petromyzon marinus (sea lamprey) and were conducted with concentrations that bracketed the predicted minimum lethal concentration required to control larval sea lamprey. Mussel species’ NOEC, LOEC, LC25, and LC50 values ranged from 1.33 to 2.12, 1.71–2.66, 1.75–3.05, and 2.03–4.84 times field determined LC99.9s for sea lamprey (×SLLC99.9) in TFM-only toxicity tests, and from 1.36 to 1.70, 1.68–2.03, 1.86–2.10, and 2.35–2.68 × SLLC99.9 for TFM:1%Nic toxicity tests, respectively. Fish species NOEC, LOEC, LC25, and LC50 values ranged from 0.60 to 1.89, 0.73–2.13, 0.72–2.11, and 0.76–2.18 × SLLC99.9 in TFM-only toxicity tests, and from 0.64 to 2.48, 0.85–3.10, 0.74–3.05, and 0.78–3.16 × SLLC99.9 for TFM:1%Nic toxicity tests, respectively. Amphibian species NOEC, LOEC, LC25, and LC50 values ranged from 0.74 to 0.75, 0.85–0.95, 0.83–0.87, and 0.85–0.91 × SLLC99.9 in TFM-only toxicity tests, and from 0.63 to 0.65, 0.80–0.88, 0.77–0.82, and 0.78–0.87 × SLLC99.9 for TFM:1%Nic toxicity tests, respectively. Generally, mussel species were tolerant, fish sensitivities were variable, and the amphibian species was sensitive to TFM and TFM:1%Nic.

The distribution and chemosensory responses of pharyngeal taste buds in the sea lamprey Petromyzon marinus.

Little is known about the chemosensory system of gustation in sea lampreys, basal jawless vertebrates that feed voraciously on live prey. The objective of this study was to investigate taste bud distribution and chemosensory responses along the length of the pharynx in the sea lamprey. Scanning electron microscopy and immunocytochemistry revealed taste buds and associated axons at all six lateral pharyngeal locations between the seven pairs of internal gill pores. The most rostral pharyngeal region contained more and larger taste buds than the most caudal region. Taste receptor cell responses were recorded to sweet, bitter, amino acids and the bile acid taurocholic acid, as well as to adenosine triphosphate. Similar chemosensory responses were observed at all six pharyngeal locations with taste buds. Overall, this study shows prominent taste buds and taste receptor cell activity in the seven pharyngeal regions of the sea lamprey.

The Impact of Sex Ratio Adjustment on Population Dynamics and Ecosystems in Marine Sea Lampreys

The Impact of Sex Ratio Adjustment on Population Dynamics and Ecosystems in Marine Sea Lampreys

Research on the Sex Ratio Variation of Sea Lampreys and Its Ecological Impact Based on the Lotka-Volterra Competition Model

Research on the Sex Ratio Variation of Sea Lampreys and Its Ecological Impact Based on the Lotka-Volterra Competition Model

Wetted Ramps Selectively Block Upstream Passage of Adult Sea Lampreys

Dams fragment stream habitats and fishways around dams typically serve few species that are strong swimmers or jumpers. We tested a prototype wetted ramp designed to allow upstream passage of small-bodied fishes while blocking upstream movement of invasive sea lampreys in the Laurentian Great Lakes. We tested short, smooth ramps with 5–10 mm water depth in various combinations of ramp angle, water flow, and swim channel width with the aim to selectively block adult migrating sea lampreys (Petromyzon marinus) while passing sub-adult white suckers (Catostomus commersonii) and creek chubs (Semotilus atromaculatus). Sea lampreys easily passed a 0.75 ramp at a 5° angle, but very few individuals passed a similar ramp at a 10° angle, and none passed a longer ramp at a 5° angle. Limiting the amplitude of tailbeats in a narrow channel did not hamper lampreys or the other species. Greater water flow, and thereby greater immersion depth on the ramp, fostered passage for all species. Smaller-bodied individuals of creek chubs and white suckers performed best on the ramp. We showed that wetted ramps could be incorporated into fishways at low-head dams to aid the passage of smaller-bodied fishes while also blocking the spawning migration of adult sea lampreys.

Speed kills? Migrating sea lamprey increase speed when exposed to an antipredator cue but make worse short-term decisions

There is growing evidence that a natural repellent, injury-released alarm cues, can be used to guide the movements of invasive fishes to achieve management goals. However, because this process involves perception, downstream cognitive processing of sensory information affects decisions regarding expression of antipredator behavior. Response habituation, wherein repeated or continuous exposure to a cue reduces behavioral response rates, is an oft-cited challenge for use of predation cues as conservation tools. Habituation may be delayed or prevented by altering the concentration and/or the temporal pattern of odor release (pulses of odor vs continuous application). We examined the effects of varying odor concentration and exposure regime (continuous vs pulsed) on behavioral response of adult sea lamprey (Petromyzon marinus) to conspecific alarm cue in a two-choice maze. We found that exposure to alarm cue induced more frequent and rapid upstream movement, regardless of exposure regime. There was also clear evidence of a speed-accuracy tradeoff, wherein sea lamprey that took longer to arrive at the bifurcation in the maze were more likely to avoid the arm activated with alarm cue. We could not ascertain the value of increasing concentration or pulsing the alarm cue on preventing habituation, as habituation did not occur. We hypothesize dishabituation to the alarm cue occurred immediately prior to testing due to handling that may have inadvertently simulated an unsuccessful predator attack. If true, incorporating dishabituating stimuli may prove a useful means to maintain the efficacy of alarm cue when applied as a repellent to manipulate the movements of sea lamprey.

WITHDRAWN: The main threats facing the eel (Anguilla anguilla) and the sea lamprey (Petromyzon marinus) in Galicia (NW Spain) through Partial Least Squares Path Modelling

Migratory fish are very important species from an ecological and socioeconomic point of view, but they suffer the effects of many threats such as climate change, pollution, or overfishing, thus contributing to the decline of these species. To study the main factors influencing these species, Partial Least Squares Path Modelling (PLS-PM) methodology has been used to analyse and quantify the main threats facing two highly relevant migratory species: the eel (Anguilla anguilla) and the sea lamprey (Petromyzon marinus). Based on this statistical approach, two models have been developed for a total of 14 rivers located in the Autonomous Community of Galicia (NW Spain), one for the eel and the other for the lamprey. For the construction of the models, the influence of environmental factors, surface water quality and anthropogenic impacts on the population of these species has been studied. Two scenarios have also been simulated to assess how the application of corrective measures to reduce the anthropogenic impact implies important improvements to the eel and lamprey populations. The results of the models developed indicate that the variables analysed predict 69% of the eel "Population", with the weight of the measured variables (MV) 'Water treatment plants' having the most substantial weight (W=0.939) followed by the significant negative influence of 'Surface area of reservoirs and rivers' (W=-0.746). Similarly, in the lamprey model, an R2 of 0.58 has been obtained, where the negative influence of the MV "Agricultural nitrate discharge points" (-0.938) stands out substantially. In relation to the scenarios developed for both species, we highlight that the application of measures aimed at reducing anthropogenic pressure manages to mitigate the impact by 4.82% in the case of eel and by 1.37% in the case of lamprey. The set of models and scenarios proposed will make it possible to design preventive and corrective measures to mitigate the impacts affecting these populations, guaranteeing the integrated management of these species, and improving future decision-making, thus strengthening environmental governance.

Editing Streptomyces genome using target AID system fused with UGI-degradation tag.

The utilization of Streptomyces as a microbial chassis for developing innovative drugs and medicinal compounds showcases its capability to produce bioactive natural substances. Recent focus on the clustered regularly interspaced short palindromic repeat (CRISPR) technology highlights its potential in genome editing. However, applying CRISPR technology in certain microbial strains, particularly Streptomyces, encounters specific challenges. These challenges include achieving efficient gene expression and maintaining genetic stability, which are critical for successful genome editing. To overcome these obstacles, an innovative approach has been developed that combines several key elements: activation-induced cytidine deaminase (AID), nuclease-deficient cas9 variants (dCas9), and Petromyzon marinus cytidine deaminase 1 (PmCDA1). In this study, this novel strategy was employed to engineer a Streptomyces coelicolor strain. The target gene was actVA-ORF4 (SCO5079), which is involved in actinorhodin production. The engineering process involved introducing a specific construct [pGM1190-dcas9-pmCDA-UGI-AAV-actVA-ORF4 (SCO5079)] to create a CrA10 mutant strain. The resulting CrA10 mutant strain did not produce actinorhodin. This outcome highlights the potential of this combined approach in the genetic manipulation of Streptomyces. The failure of the CrA10 mutant to produce actinorhodin conclusively demonstrates the success of gene editing at the targeted site, affirming the effectiveness of this method for precise genetic modifications in Streptomyces.

Evaluation or RetrogressionThe sex ratio dettermination pattern of lamprey

In this study, we investigate the profound impacts of the sex determination pattern in the invasive sea lamprey on ecological dynamics and focuses on how the pattern influences the population based upon the interplay of system stability. In the initial segment, we employ the Lotka-Volterra model and system dynamics to study lamprey sex ratios correlation with ecosystem stability. Focusing on food impact on lamprey sex ratio, it can be delved that its sex determination maintains the prey population at a consistently low level, thereby affecting population stability. The following segment explores lamprey sex ratios evaluations utilizing system dynamics model based on Analytic Hierarchy Process (AHP). Cellular Automata (CA) is employed for cross-validations, revealing nuanced insights into the adaptive advantages and vulnerabilities of lampreys reproductive strategy, highlighting the resilience of lamprey populations under natural pressures. Our modeling, with visualizations and simulations, supports findings and highlights avenues for future research. This study contributes to the evaluations of bio sex ratio switching, contributing for the possible ecosystem conservation strategies.

Study of species relationship analysis based on the CMFR model

This study employs the Composite Multi-Factor Relationship (CMFR) model to delve into the complex interactions between sea lampreys and their prey within the Great Lakes, using a dataset from 2001 to 2011. It reveals how fluctuations in the sex ratio of lampreys alongside environmental factors critically influence the stability of the ecosystem. Through meticulous integration of data regarding plankton conditions and lamprey sex ratios, the research outlines the profound impact these variables have on predation behaviors and, subsequently, the ecological balance. The findings illuminate the utility of the CMFR model in shedding light on species interactions, providing vital insights for the strategic management of invasive species to safeguard ecosystem health. Additionally, the study emphasizes the importance of considering diverse biological and environmental factors in ecosystem management, offering valuable strategies for maintaining biodiversity and ecological stability. This comprehensive analysis contributes significantly to our understanding of predator-prey dynamics and the broader implications for aquatic ecosystem sustainability.

Logistic and Lotka-Volterra based dynamic ecological modeling of Sea lamprey.

Logistic and Lotka-Volterra based dynamic ecological modeling of Sea lamprey.