Functional changes of the visual system of the damselfish Dascyllus marginatus along its bathymetric range

Brokovich, Eran, Ben-Ari, Tomer, Kark, Salit, Kiflawi, Moshe, Dishon, Gal, Iluz, David and Shashar, Nadav (2010) Functional changes of the visual system of the damselfish Dascyllus marginatus along its bathymetric range. Physiology and Behavior, 101 4: 413-421. doi:10.1016/j.physbeh.2010.07.006


Author Brokovich, Eran
Ben-Ari, Tomer
Kark, Salit
Kiflawi, Moshe
Dishon, Gal
Iluz, David
Shashar, Nadav
Title Functional changes of the visual system of the damselfish Dascyllus marginatus along its bathymetric range
Journal name Physiology and Behavior   Check publisher's open access policy
ISSN 0031-9384
Publication date 2010-11-01
Year available 2010
Sub-type Article (original research)
DOI 10.1016/j.physbeh.2010.07.006
Open Access Status Not yet assessed
Volume 101
Issue 4
Start page 413
End page 421
Total pages 9
Place of publication Philadelphia, PA United States
Publisher Elsevier Inc.
Language eng
Abstract Shallow-water zooplanktivorous fish rely on their vision for foraging In shallow water feeding efficiency decreases in dim light and thus the fish cease foraging at crepuscular hours Creatures living in the lower parts of their depth ranges are expected to be exposed to limited light levels for longer hours However observations of the zooplanktivore Dascyllus marginatus showed little change in foraging duration down to 40 m deep We asked whether the visual system s functionality changes with depth along the depth range of this damselfish we examined eye and retina anatomy for changes in visual acuity and light sensitivity and used the optomotor response to test for spatial and temporal light summation We found only minor changes in the anatomy of the eye that are not expected to affect visual sensitivity or acuity However behavioural experiments showed that the deeper water fish s test performance exceeded those of fish in shallow water under lower light levels We found that deeper water fish responded to the optomotor test at lower light levels and also had more discriminating visual acuity in low light which can Increase their potential reactive distance The plastic adaptive ability of the visual system to low light levels may explain the fish s ability to inhabit deeper reef habitats and thus expand their depth range limits (C) 2010 Elsevier Inc All rights reserved
Formatted abstract
 Shallow-water zooplanktivorous fish rely on their vision for foraging. In shallow water, feeding efficiency decreases in dim light and thus the fish cease foraging at crepuscular hours. Creatures living in the lower parts of their depth ranges are expected to be exposed to limited light levels for longer hours. However, observations of the zooplanktivore Dascyllus marginatus showed little change in foraging duration down to 40 m deep. We asked whether the visual system's functionality changes with depth along the depth range of this damselfish; we examined eye and retina anatomy for changes in visual acuity and light sensitivity and used the optomotor response to test for spatial and temporal light summation. We found only minor changes in the anatomy of the eye that are not expected to affect visual sensitivity or acuity. However, behavioural experiments showed that the deeper water fish's test performance exceeded those of fish in shallow water under lower light levels. We found that deeper water fish responded to the optomotor test at lower light levels and also had more discriminating visual acuity in low light, which can increase their potential reactive distance. The plastic adaptive ability of the visual system to low light levels may explain the fish's ability to inhabit deeper reef habitats and thus expand their depth range limits.
Keyword Gulf of Aqaba
Spatial summation
Temporal summation
Coral Reef Fish
Technical diving
Deep Sea
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID SfP 981883
740/04
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biological Sciences Publications
 
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