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).

Thank you for your attention