Crustacean larva raising method and apparatus

Details Crustacean larva raising method and apparatus Crustacean larva raising method and apparatus

2002-06-24

2003-05-13

Abbott, Yvonne (Department: 3644)

Animal husbandry

Aquatic animal culturing

Crustacean culturing

C119S205000

Reexamination Certificate

active

06561134

ABSTRACT:

This invention relates to a crustacean larva raising method and apparatus.
This invention has particular but not exclusive application to larva raising method and apparatus for use with Thenus spp., and for illustrative purpose reference will be made to such application. However, it is to be understood that this invention and inventive elements thereof could be used in other applications, such as rock lobster and slipper lobster larvae.
There have been many attempts made to develop larva-rearing strategies for commercial species of crustacea. To date these have been concentrated on developing strategies for species of rock and slipper lobster larvae. A summary of these processes is given in Table 1.
TABLE 1
No. sur-
Tank
Species
Authors
Survival
vived
size
South African
Kittaka
<1%
1 from
100
l
rock lobster
(1988)
15,000
(
Jasus lalandii
)
Southern rock
Kittaka et al.
<1%
2 from
100
l
lobster (
Jasus
(1988),
16,000
72
l × 4
edwardsii
)
Illingworth et al.
<1%
1 from
(1997)
 6,000
European rock
Kittaka and Ikegami
<1%
1 from
100
l
lobster (
Palinurus
(1988)
 5,000
elephas
)
Japanese rock
Yamakawa et al.
<1%
1 from
1
l
lobster
(1989)
 1,000
bowls
(
Panulirus
Kittaka and Kimura
<1%
2 from
100
l
japonicus
)
(1989)
20,000
Slipper lobsters
Takahashi and
 1.8%
6/330
100
l
(Ibacus spp.)
Saisho (1978)
(nistos)
Marinovic et al.
15%
6 from
7
l
(1994)
   40
A chronology of larval efforts is given in Table 2.
TABLE 2
Bay Lobster
Year
species
Survival
Other Species
Survival
1978
Slipper lobsters
6 from 40
(Ibacus spp)
Takahashi and
Saisho
1988
South African rock
1 from 15,800
lobster
(
Jasus Ialandii
)
Kittaka
1988
Southern rock
2 from 16,000
lobster
(
Jasus edwardsii
)
Kittaka et al.
1988
European rock
1 from 5,000
lobster
(
Palinurus elephas
)
Kittaka and Ikegami
1989
Japanese rock
1 from >1,000
lobster
1 from 20,000
(
Panulirus
japonicus
)
Yamakawa et al.
Kittaka and Kimura
1994
Slipper lobster
6 from 330
(
Ibacus peronii
)
Marinovic et al.
1995
Successful
1 larvae/L
larval rearing
up to 100
by small vessel
(Survival
(1 L glass
0-80%)
bowls)
1997
Southern rock
1 from 6,000
lobster
(
Jasus edwardsii
)
Illingworth et al.
The present four major commercial-research rearing tank systems for rock and slipper lobster larvae are, for the Southern rock lobster, (
Jasus edwardsii
) the systems developed by the Tasmanian Aquaculture and Fisheries Institute (TAFI), for
J. edwardsii
and the Eastern rock lobster, (
Jasus verreauxi
) the systems developed by the National Institute of Water and Atmospheric Research (NIWA) of New Zealand, for the Japanese rock lobster, (
Panulirus japonicus
) the system developed by Fisheries Research Institute of Mie (FRIM), the Japan Sea-Farming Association (JSFA) and Research Institute for Science and Technology of The Science University of Tokyo, all of Japan. The broad features of these systems and the results published are as follows:
1. (TAFI)
Southern rock lobster
10 l water in 30 l tanks
Stocking density of 20 newly hatched larvae per l
No juveniles obtained.
2. Upwelling tank system (NIWA)
Southern rock lobster
Combination of 4×72 l tanks
Stocking density of 26 newly hatched larvae per l
Only one juvenile survived in 1990
3. Zero water movement tank system (FRIM)
Japanese rock lobster
150-180 l in 200 l tanks
Stocking density of 20 newly hatched larvae per l
Less than 1% survival to the juvenile stage (up to 10 juveniles)
4. (JSFA)
Japanese rock lobster
150-180 l in 200 l tanks
Stocking density of 20 newly hatched larvae per l to 1 final stage larvae per l
Approximately 1% survival to the juvenile stage (up to 100 juveniles)
Thenus spp., commonly known as Moreton Bay bugs, Slipper lobsters and Bay lobsters, are found along the entire northern coast of Australia from Shark Bay in Western Australia to Coffs Harbour in northern New South Wales (Kailola et al., 1993). There are two Thenus species: Mud bugs (Thenus sp.) and Sand bugs (
Thenus orientalis
). Mud bugs are brown overall and have brown stripes on their walking legs, while Sand bugs are speckled overall and have spots on their walking legs. Mud bugs prefer a bottom of fine mud, and are typically trawled from inshore coastal waters of 10 to 30 meters depth. Sand bugs tend to prefer sediments with a larger, coarser particle size, and are usually trawled from a depth of 30 to 60 meters in the coastal shelf and offshore areas.
Currently, commercial aquaculture of Moreton Bay bugs is not being carried out anywhere in the world. The major hurdle in commercialisation is the difficulty in maintaining the bugs through the larval stages. Like other slipper or rock lobster species, Moreton Bay bugs have a very characteristic flattened larval stage called the phyllosoma. They circulate in the plankton, rising and falling in the water column, and this makes it difficult to adjust the culture environment.
Recently however, a comprehensive study of the culture conditions of Moreton Bay bug phyllosomas was undertaken, suggesting high potential for commercial aquaculture of these species (Mikami, 1995). Phyllosomas of Moreton Bay bugs pass through four larval stages in 25 to 35 days, with a high level of survival on a small scale and take one year to achieve commercial size (250 g).
Following the study by Mikami (1995), further research has been undertaken by the present applicant over the past five years. The major aim of this study is the commercialisation of Moreton Bay bug aquaculture from the small, experimental scale. To date, the single most important issue has been to solve the technical aspects of Moreton Bay bug larval rearing.
In one aspect this invention resides in a crustacean larva raising method including the steps of:
providing a tank adapted to hold larva raising medium to a depth of at least 10 cm;
continuously supplying substantially sterilized, filtered larva raising medium to said tank through a plurality of outlets disposed about the tank and adapted to cause horizontal circulation of said medium and having an outlet flow velocity selected to prevent larva damage;
continuously draining said medium through a drain assembly including a larva screen having a flow velocity of said medium therethrough selected to prevent damage to larvae, and
maintaining said medium at a temperature selected to accommodate the larva species to be raised.
In a further aspect, this invention resides broadly in crustacean larva raising apparatus including:
a supply of substantially sterilized, filtered larva raising medium;
a tank adapted to hold said larva raising medium to a depth of at least 10 cm;
a plurality of outlets connected to said supply and adapted to deliver and cause horizontal circulation of said medium in said tank;
drain means having a larva screen and configured to maintain a selected level in said tank, and
temperature control means for said medium.
The larval rearing tank may be round or oval in horizontal cross section such that a continuous one-way circulation may be maintained. Alternatively, the larval rearing tank may comprise an annular tank. As a yet further alternative, the larval rearing tank may comprise an annular raceway having straight portions closed by end portions. Preferably, the raceway comprises a modular construction of curved and straight portions, whereby the linear dimensions and thus holding capacity may be selected. For example, the modular components may be moulded in plastics material and be adapted to be bolted up in assembly to form the raceway. The modular components may be provided with preformed joint sealing, or may in the alternative be sealed with an in situ cast sealing such as curable silicon or other sealant.
The tank depth is preferably less than one meter. Preferably, the water depth is maintained at about 10 to 20 cm. This relatively shallow depth will allow increasing feeding frequency of larvae. In the case of the preferred annular and or modular raceway construction, the section of the raceway may be for example 30 cm deep. Whilst the width of the section may be of any suitable dimension det

Affiliated with

Also associated with

Rating

Crustacean larva raising method and apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Crustacean larva raising method and apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Crustacean larva raising method and apparatus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3086213