Library Open Repository

The eye of the southern calamary Sepioteuthis australis embryos and hatchlings: development, screening pigment migration and pupil response

Downloads

Downloads per month over past year

Bozzano, A and Pankhurst, PM and Moltschaniwskyj, NA and Villanueva, R (2009) The eye of the southern calamary Sepioteuthis australis embryos and hatchlings: development, screening pigment migration and pupil response. Marine Biology: international journal on life in oceans and coastal waters, 156 (7). pp. 1359-1373. ISSN 0025-3162

[img] PDF
Bozzano_et_al_2009.pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.

Abstract

Eye development, optical properties and photomechanical responses were examined in embryos and hatchlings of the southern calamary, Sepioteuthis australis. This species occurs in shallow coastal waters in Australia and New Zealand, and the egg masses were collected in October and December 2004 from Great Oyster Bay, Tasmania. At the earliest developmental stage the eye of the squid was comprised of a hemispherical cup of undiVerentiated neural retina, while presumptive iris cell layers and lentigenic precursor cells enclosed a posterior eye chamber. DiVerentiation of the proximal and distal processes was observed in correspondence with the cornea development and lens crystallization, and occurred before diVerentiation of the neural retina, which was complete prior to hatching. Longer photoreceptor distal processes were Wrst observed just prior to hatching in the dorsal-posterior retina. After hatching, this diVerence was much more evident and higher photoreceptor density was found in the central retina. This indicates that the eye of S. australis at this age uses diVerent retina areas for diVerent visual tasks. Optical sensitivity and resolution suggest that juvenile S. australis are diurnal. This study also found functional photomechanical responses of visual screening pigment migration and pupil constriction in S. australis embryos, although complete functionality of the pupil at this stage was uncertain. However, the pupils of squid aged 2 days closed almost completely under bright conditions, showing that photomechanical responses were highly developed in the juvenile squid. These Wndings indicate that squid embryos are able to perceive visual stimulation, suggesting an early reliance on vision for survival after hatching.

Item Type: Article
Journal or Publication Title: Marine Biology: international journal on life in oceans and coastal waters
Page Range: pp. 1359-1373
ISSN: 0025-3162
Identification Number - DOI: 10.1007/s00227-009-1177-2
Additional Information: The original publication is available at www.springerlink.com
Date Deposited: 19 Jul 2010 00:56
Last Modified: 18 Nov 2014 04:12
URI: http://eprints.utas.edu.au/id/eprint/9966
Item Statistics: View statistics for this item

Repository Staff Only (login required)

Item Control Page Item Control Page