Effect of growth on reproduction in the freshwater amphipod,Hyalella azteca(Saussure)

✍ Scribed by David W. Moore; J. Daniel Farrar

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 639 KB
• Volume: 328
• Category: Article
• ISSN: 1573-5141
• DOI: 10.1007/bf00018709

✦ Synopsis

A gradient in H. azteca growth was created by reducing food ration . .Tests were initiated with neonates (<48 h old) and the effects of an altered food ration on survival and growth were examined after 10 and 49 days . Growth rates decreased significantly with reduced food ration (10 day growth rates ranged from 1 .2 tg d -1 in the highest feeding regime to 0 .5 tg d -1 in lowest feeding regime) . Survival after 10 days was not affected by ration, ranging from 86 to 96% . A growth rate of 1 .2 jig d -1 at day 10 resulted in mean dry weight (1 .0 mg), survival (62%) and reproduction (9 .3 neonates/female) at day 49 similar to reported values for this species . Growth rates <0 .9 Ag d-1 at day 10 corresponded to significantly reduced reproduction at day 49 (i .e ., < 1 neonate per female) . Time to the onset of amplexus increased with decreasing ration suggesting reduced ration may have delayed reproduction .