Predator-induced vertical behavior of a ctenophore

Abstract

Although many studies have focused on Mnemiopsis leidyi predation, little is known about the role of this ctenophore as prey when abundant in native and invaded pelagic systems. We examined the response of the ctenophore M. leidyi to the predatory ctenophore Beroe ovata in an experiment in which the two species could potentially sense each other while being physically separated. On average, M. leidyi responded to the predator's presence by increasing variability in swimming speeds and by lowering their vertical distribution. Such behavior may help explain field records of vertical migration, as well as stratified and near-bottom distributions of M. leidyi.

Elevating the predatory effect: Sensory-scanning foraging strategy by the lobate ctenophore M nemiopsis leidyi

“…The mean capture efficiency of encounters below 8 mm s −1 was 75.0%. However, there were very few events that occurred at swimming velocities above 6 mm s −1 because M. leidyi generally swims with a mean velocity of 2 mm s −1 (Titelman et al ). Although in turbulence, higher swimming speeds are observed (Sutherland et al )…”

“…These behavioral capabilities enable M. leidyi to sense the presence of copepods in the fluid between the lobes and close the lobes before contact is made, greatly enhancing retention efficiencies (Costello et al ). M. leidyi is also known to use chemosensory capabilities to avoid predators (Titelman et al ). Therefore, while more research needs to quantitatively evaluate the sensory capabilities of M. leidyi , present knowledge indicates that they are likely capable of detecting even passive prey before the prey contact the auricles.…”

“…Capture efficiencies and ingestion rates of passive suspension feeders are highly sensitive to flow conditions and are frequently reduced at both low and high flow levels (Best ; Sebens et al ). Although flow rates through M. leidyi are directly related to the swimming rates (Colin et al ), measured capture efficiencies did not decline during more rapid swimming [except at the highest swimming speeds which are not commonly observed (Titelman et al ) except at times in turbulent environments (Sutherland et al )]. Feeding rates of many aquatic predators, most commonly ambush foragers, are characterized by decreased performance at higher turbulence levels so that feeding rates exhibit a dome‐shaped curve in relation to turbulence intensity (Mackenzie et al ; Saiz et al ).…”

Fine-scale planktonic habitat partitioning at a shelf-slope front revealed by a high-resolution imaging system

“…Since some lobate ctenophores have been demonstrated to alter their swimming speed and vertical distribution in the presence of Beroe spp. predators (Titelman et al, 2012), the vertical separation between Beroe spp. and lobate ctenophores could indicate avoidance behavior or top down regulation.…”

Benthic ctenophores (Platyctenida: Coeloplanidae) in South Florida: predator–prey interactions

“…; Costello & Coverdale ; Sullivan & Gifford ; Titelman et al. ). Much of this work has resulted from the realization that ctenophores play a pivotal role in affecting pelagic food chains and trophic structure, fisheries stocks, and the success of invasive species (Costello et al.…”