Shrinkage Rates In Newly Hatched Larvae Of Macrobrachium vollenhovenii (Herklot's) (Decapoda, Palaemonidae)

Abstract

The effect of formalin/sea-water solution (2% and 4% formalin conc. buffered with borax) on the total lengths of preserved samples of newly hatched Macrobrachium vollenhovenii larvae was investigated. The influence of an aesthesia on larvae in 2% and 4% formal in was also studied to determine the combine influence of an aesthesia and formal in on these specimen. Shrinkage was similar in all subgroups studied (P>0.05). Prior to shrinkage, specimens showed initial increases in total length, which finally stabilized after 20 days preservation. Larger specimen exhibited lower shrinkage rates than smaller specimens (P>0.05). Shrinkage did not take place in larval stages 4 and 5. Specimens above zoea 5 exhibited a drastic size reduction on preservation. Anesthesia influenced shrinkage drastically.

KEY WORDS: Shrinkage ,Larvae, M. Vollenhovenii , Formalin , Anesthesia.

Global Journal of Environmental Sciences Vol.3(1&2) 2004: 41-43