Cardiovascular performance of six species of field-acclimatized centrarchid sunfish during the parental care period.

Parental care is an energetically costly period of the life history of many fish species characterized by extended high intensity activity. To date, there have been no studies that have investigated the cardiovascular correlates of extended parental care in fish. Using Doppler flow probes, the cardiovascular performance of six syntopic centrarchid fish species (N=232) that provide sole, male parental care was examined across a range of water temperatures that encompass their reproductive periods (14-26 degrees C).

A longitudinal and cross-sectional analysis of total body oxygen store development in nursing harbor seals (Phoca vitulina).

This study compared the efficacy of longitudinal and cross-sectional sampling regimes for detecting developmental changes in total body oxygen (TBO(2)) stores that accompany behavioral development in free-ranging harbor seal pups. TBO(2) stores were estimated for pup (n = 146) and adult female (n = 20) harbor seals. Age related changes were compared between pups captured repeatedly during the lactation period (longitudinal dataset) and a second group of pups handled only once (cross-sectional dataset).

Erythropoietin concentration in developing harbor seals (Phoca vitulina).

Tissue hypoxia elicits the production of erythropoietin (Epo), a hormone that stimulates red blood cell production. In young diving mammals, oxygen is stored primarily in the blood, and blood oxygen stores increase significantly during the first weeks of life. In an effort to establish the role of Epo during this period of blood development, this study measured Epo concentration in plasma of 134 harbor seal (Phoca vitulina) pups and adults.

Diving heart rate development in postnatal harbour seals, Phoca vitulina.

Harbour seals, Phoca vitulina, dive from birth, providing a means of mapping the development of the diving response, and so our objective was to investigate the postpartum development of diving bradycardia. The study was conducted May-July 2000 and 2001 in the St. Lawrence River Estuary (48 degrees 41'N, 68 degrees 01'W).

Developmental changes in cardiorespiratory patterns associated with terrestrial apnoeas in harbour seal pups.

During the nursing period seals undergo several physiological and behavioural changes. A key component of development is increased cardiorespiratory control, fundamental for breath-holding and thus diving. This study focused on the ontogenetic changes in cardiac responses to respiration in quietly resting, pre-weaned harbour seal pups (Phoca vitulina).

Understanding fish behavior, distribution, and survival in thermal effluents using fixed telemetry arrays: a case study of smallmouth bass in a discharge canal during winter.

Advances in telemetry have facilitated the continuous monitoring of fish position and movement. At present, there are few examples where this approach has been applied to environmental monitoring or assessment. Here we 1) present a case study that used a fixed antenna array and continuously scanning coded receiving system to monitor the movement of radio-tagged smallmouth bass ( Micropterus dolomieu) in a thermal discharge canal on Lake Erie during the winter of 1998/1999, and 2) evaluate the use of fixed telemetry arrays for environmental monitoring.

Effects of incremental increases in silt load on the cardiovascular performance of riverine and lacustrine rock bass, Ambloplites rupestris.

Rock bass (Ambloplites rupestris) are a widespread centrarchid species with both riverine and lacustrine populations. After precipitation events, rivers often carry elevated silt loads, where as lakes generally remain free from suspended silt and sediment. To examine the physiological effects of silt on rock bass, we conducted a series of experiments using fish from Lake Opinicon and the Grand River in Ontario.

Low temperature cardiac response to exhaustive exercise in fish with different levels of winter quiescence.

We examined the cardiac responses of different fish species to anaerobic exercise at low temperatures (3 degrees C). Three species of sympatric warmwater fish with perceived differences in winter activity were used for this comparative study: the winter-quiescent largemouth bass (Micropterus salmoides); the winter-active white bass (Morone chrysops); and the intermediately winter-active black crappie (Pomoxis nigromaculatus). Perceived differences in winter activity were reflected in cardiac responses; e.

Determination of fish community composition in the untempered regions of a thermal effluent canal--the efficacy of a fixed underwater videography system.

High flows and deep waters associated with thermal discharge canals invoke safety concerns and preclude the use of conventional fish sampling methodologies. Despite these challenges, it is critical that assessments of thermal effects from power generation do not rely solely on data collected in the plume, but also focus on fish living in the canal, particularly in regions above the zone of tempering influence. We deployed a fixed underwater videography apparatus to monitor the community composition and abundance patterns of fish in the Nanticoke thermal generating discharge canal on the north shore of Lake Erie from February 1, 1999 until July 31, 1999.