Control of spawning in the tunicateStyela plicata by variations in a natural light regime

✍ Scribed by West, Alan B. ;Lambert, Charles C.

• Book ID: 102891261
• Publisher: John Wiley and Sons
• Year: 1976
• Tongue: English
• Weight: 555 KB
• Volume: 195
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401950211

✦ Synopsis

Abstract

The physical parameters controlling the release of gametes in Styela plicata were studied in laboratory experiments designed to simulate environmental conditions. Gravid animals left in constant light did not spawn until subjected to a minimum dark period followed by a sufficient amount of light. The maximum spawning success, determined by laboratory experiments, was found during the period between September, 1974 and March, 1975. The minimum dark adaption time, derived statistically from the spawning curve, was found to be 8 hours, 30 minutes. Increasing the dark adaption time resulted in decreasing the amount of light necessary to induce spawning. The total time for an entire spawning cycle (i.e., from the beginning of the dark adaption period to gamete release) was found to be approximately 24 hours. Field collection data supported the laboratory observations showing gamete release in the late afternoon, close to sunset. The amount of dark adaption affects the amount of light necessary to induce spawning suggesting a reversible photochemical reaction. Temperature limits for spawning in the laboratory were found to be 11–28°.