larval development on balanus amphitrite (cirripedia
TRANSCRIPT
Larval development on Balanus amphitrite (Cirripedia: Thoracica): implications in
biofouling and bioinvasion
Dattesh Desai and A. C. AnilNational Institute of Oceanography, Goa
Predation
Misrouting and Dispersion
Starvation
Development in Balanus amphitrite
I
II
Adult
StarvationII
III IVV VI
Experimental protocolThe role of food type temperature and starvation on larval development
Mass reared with S. costatum and C. calcitrans
Age 0 d 1 d 2 d 3 d 4 d 5 d
Starved at 5, 15 & 25º C ,
Every 12h, larvae (n=24) were from starvation batches were reared individually using S.costatum and C. calcitrans
Metamorphic success Instar Duration Total Naupliar Duration
Observations made for
40
60
80
1005° C starved 15° C starved 25° C starved
mor
phos
is
Zero day
Results
0
20
40
C 24 48 72 96 120 144 168 192 216 C 24 48 72 96 120 144 168 192 216 C 24 48 72 96 120 144 168 192 216
Starvation Duration (Hours)
% m
eta
2
3
4
tion
(day
s)
S. costatum C. calcitrans
Results
Zero day
0
1
2
Starvation Duration (Hours)
Inst
ar D
urat
C 24 48 72 96 120 144 168 192 216 C 24 48 72 96 120 144 168 192 216
Experimental protocolComparison of nutritional status of laboratory and field reared larvae
Size
Lab rearedField reared
Leng
th (µ
m)
100
200
300
400
500
600p≤0.001
p≤0.001
II III IV V VI
Wid
th (µ
m)
Instars
100
200
300
400
500
600≤p 0.001
p≤0.001
1
1.5
2
RN
A:D
NA
30°C reared20°C rearedField reared
Results
0
0.5
Larval Age (Days)
0 1 2 3 4 5 6 7 8 9 10
Naupliar development duration – 8-9d
Mixed plankton availability + ?
Grazing rate ?
Rearing of Balanus amphitrite nauplii in the field
Chlorophyll a content of seawater ~ 0.3-4µg/L
Laboratory rearing of Balanus amphitritelarvae
Naupliar development duration – 4-5 daysGrazing rate – 4000 cells/hr/larvaChlorophyll a gain through feeding ~ 2-2.3 µgChl/hr/larva
Reared with 1 x 105 cells/ml of or Chaetoceros calcitrans(0.6 pg Chl/cell)
Chl/hr/larva
Differences
Food chlorophyll a concentration in laboratory15 times higherLonger Naupliar development duration in fieldField reared larvae smallere d ea ed a ae s a eRNA/DNA ratio - 0.5 – 1.7 folds lesser in fieldreared larvae as compared to lab
What are the other contributors that facilitatelarval development?
Thank you