DOI: 10.6084/m9.figshare.14384585
title: Dataset of Suction Pressure Dynamics of Sea Lampreys, Petromyzon marinus

description: Abstract<b></b>Sea lamprey, a destructive invasive species in the Laurentian Great Lakes and conservation target in North America and Europe, is among very few fishes that possess and use oral suction, yet suction has not been exploited for sea lamprey control or conservation. Knowledge of specific characteristics of sea lamprey suction (e.g., amplitude, duration, and pattern of suction events; hereafter ‘suction dynamics’) may be useful to develop devices that detect, record, and respond to the presence of sea lamprey at a given place and time. Previous observations were limited to adult sea lampreys in static water. <br>In this study, pressure sensing panels were constructed and used to measure oral suction pressures and describe suction dynamics of juvenile and adult sea lampreys at multiple locations within the mouth and in static and flowing water. An array of sensors indicated that suction pressure distribution was largely uniform across the mouths of both juvenile and adult lampreys; but some apparent variation was attributed to obstruction of sensing portal holes by teeth. Suction pressure did not differ between static and flowing water when water velocity was lower than 0.45 m/s. Such information may inform design of new systems to monitor behavior, distribution and abundance of lampreys.<b></b>Methods<b>The Pressure-Sensing Apparatuses:</b>Commercial vacuum pressure sensors (Honeywell 40PC0152A) were used to construct the sensing system for monitoring vacuum pressures exerted by sea lampreys on test surfaces. Each pressure sensor had an operating pressure range of 0 kPa to –103.4 kPa and response time of 1 ms maximum. Two types of pressure-sensing apparatuses were developed for comprehensive experiments, including a panel with a single sensing port, and a panel with a 9-port circular pressure sensing matrix, respectively.<br><b>Experimental Animals:</b>Three experiments were conducted in 2019 and 2020 using spawning phase adult and parasitic juvenile sea lampreys. Prior to tests, body weight, total body length, and mouth diameter were measured for most, but not all sea lampreys. All sea lamprey experiments were performed in accordance with protocols and guidelines approved by Michigan State University's Institutional Animal Care and Use Committee (IACUC, No. 02/18-028-00). After the suction pressure experiments in this study, the sea lampreys were housed for use in further research by Hammond Bay Biological Station.<br><strong>Data Collection</strong>:During each test, a sea lamprey was gently held with its mouth centered over the port on the acrylic plate until it attached to the plate via oral suction. Pressure data from the sensor, measured in kPa, were acquired by an Arduino processor board (Arduino Uno for single port sensor; Arduino Mega 2560 for 9-port sensing panel) at a sampling frequency of 200 Hz and stored in a computer.<br><strong>Data Analysis:</strong>For each individual sea lamprey, maximum observed suction pressure, minimum observed suction pressure, and median leakage time were calculated during each test. Non-parametric Mann-Whitney U Tests were used to test the null hypothesis that maximum free suction pressure (in static or flowing water without being manually pulled) and median leakage time did not differ between life stages (juvenile vs. adult; sexes combined for adults) or between sexes (male vs. female; adult life stage only). Test statistics and p-values were calculated according to [Zar, JH. Biostatistical analysis. 1999]. Simple linear regressions were used to determine if maximum suction pressure were related to body weight within each group (i.e., adult male, adult female, juvenile). Linear regressions were also used to determine if leakage time was related to maximum suction pressure within each group. Coefficient of determination (R2) was used as an indicator of strength of association between independent (e.g., body weight) and response variables (e.g., max. suction pressure). Two-sided T tests were used to test the null hypothesis that the slope between independent and dependent variables was not equal to zero. Regression analysis were conducted using the Regression Analysis Tool in Microsoft Excel 2008.