Post on 13-Jan-2016
Breeding performance of Bithynia siamensis goniomphalos populations in relation to prevalence of Opisthorchis viverrini in Northeastern region of Thailand
Thanathip Lamkom1,*, Dechnarong Phosri1
Department of Fisheries, Faculty of Agriculture, Ubon Ratchathani University, Warin chamrab, THAILAND
Opisthochiasis, together with associated cholangiocarcinoma, is one of the human parasitic diseases in lower Mekong area, e.g. Thailand, Lao PDR, Cambodia, and Vietnam (Waikagul, 1998; Sripa et al., 2011; Sitthithaworn et al., 2012).
Introduction
The prevalence of liver fluke infection in Thailand was found in many provinces of Northeast region.
Source: Sripa et al. (2011)
Liver fluke, Opisthorchis viverrini can infect and inhabit within the intrahepatic bile ducts of human through undercooked fish (Grundy-Warr et al., 2012).
Source: modified from Petney et al. (2012)
Bithynia siamensis goniomphalos is recognized as the specific host of transmission in life cycle of liver fluke.
Introduction
4
Bithynia siamensis goniomphalos
There are 3 species in Thailand; B. funiculata, B. s. siamensis, and B. s. goniomphalos
Bithynia snails are oviparous animals which can spawn eggs (3-8 eggs per set) on the natural materials (rocks and gravels).
At 27-28 0C, the developmental period of B. s. goniomphalos eggs ranged 10-12 days (Kruatrachue et al., 1982).
Introduction
The habitat of B. s. goniomphalos was commonly found in the lentic waters, e.g. lakes, ponds, reservoirs and flooding area.
The richness of snail populations depend on physical and chemical parameters of water quality, e.g. salinity (2.5-5.0 ppt), water depth (30 cm), temperature (24.5-31.8 0C), and dissolved oxygen (2.03-7.66 ppm) (Petney et al., 2012).
Introduction
Objectives
To study on the breeding performance, spawningperiod, total number of spawned eggs, and hatchingperiod of B. siamensis goniomphalos in 3 populations.
To study on the embryonic development of B. siamensis goniomphalos.
Materials and methods
Site selection
LA = Lam pao reservoirNH = Nong harn reservoir UB = Ubonrat reservoir
1
2
3
8
Materials and methods
Bithynia samples
♂ ♀
♂
♀
Materials and methods
Broodstock
Materials and methods
Breeding studies
male:female = 2:3 (per box)
Water temperature = 28±1 0C
Light:dark = 8:16 hr
Materials and methods
Breeding studies
12
The embryonic development of Bithynia was divided into 5 stages; cleavage, morula, gastrula, trochophore, and hippo stages.
The yellowish zygote was encapsulated within gelatine which protected the eggs.
1st day
5th day
The 3-4 rows of fertilized eggs were attached tightly on the bottom of aquarium.
Results
1st hr 4th hr 6th hr 9th hr
12st hr 20th hr 22th hr
Zygote Cleavage
Morula
Embryonic development
26th hr 28th hr 44th hr
Trochophore
Veliger
54th hr 63h hr 69th hr
Embryonic development
Embryonic development
Hippo
102th hr 117th hr 164th hr
eye
foot
mouth
midgut gland
operculumproboscis
shell
stomach
tentacleheart
100 µm
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58
0
50
100
150
200
250
LA
UB
NH
day
num
ber
of s
paw
ned
egg
per
day
(egg
s)
Spawning period NH = 7th-60th (54 days)LA = 8th-60th (53 days)UB = 8th-53th (46 days)
Breeding performances
Figure 1 The spawned eggs per day of B. s. goniomphalos in laboratory at 28±10C for 60 days.
LA NH UB
010
20
30
40
50
Population of Bithynia
percenta
ge o
f to
tal eggs
Total number of spawned egg NH = 580±72 eggsLA = 434±123 eggsUB = 276±76 eggs
Breeding performances
Figure 2 The percentage of total spawned eggs of B. s. goniomphalos in laboratory at 28±10C for 60 days.
1 2 3 4 5 6 7 8 9 10 11 12 13 140
200
400
600
800
1000
LA
UB
NH
day
num
ber
of h
atch
ing
egg
(egg
s)
Hatching period
Breeding performances
NH = 7th-13th (7 days)LA = 8th-13th (6 days)UB = 8th-13th (6 days)
Figure 3 The hatching period of B. s. goniomphalos eggs in laboratory at 28±10C.
Discussions and conclusions
The period of embryonic development in three populations ranged 7-13 days.
There are 5 stages of embryonic development; cleavage, morula, trochophora, veliger, and hippo stages.
The breeding performances, spawning period, total number of spawned egg, and hatching period, of snail samples in NH population was faster than the other populations because the environment in NH wetland can support the viable number and embryonic development.
Source: Cantacessi et al. (2013)
The increased specific host, B. s. gonionphalos can accelerate opportunity of O. viverrini prevalence.
Discussions and conclusions
Kiatsopit et al. (2012) explained that the highest number of B. s. goniomphalos was found in Sakon Nakhon (NH) province.
NH
LA
UB
Sripa et al (2011) reported that Sakon Nakhon area (NH) showed the highest incidence of cholangiocarcinoma (CCA).
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