Lobster Health in Early Life-Stages

LOBSTER HEALTH IN EARLY LIFE-

STAGESAndrea Battison &

Jean Lavallée

AVC Lobster Science Centre

Disease Knowledge Base?

Adult Larvae & Juveniles Gaffkemia

Bumper Car Calcinosis Shell disease …..

?? ?? ?? ?? …..

Need for Knowledge? Hatcheries:

Increasing number/production

Increased risk of production-related disease can be anticipated

Develop strategies to decrease & mitigate risks Increase overall production

Hatcheries:Potential Disease Risks Intensive production model

High density Artificial food source Artificial water source Artificial water movement patterns enclosed space, ‘walls’

STRESS general increased risk of

disease

Hatcheries:Potential Release Risks?

Expose ‘wild’ larvae to hatchery-origin infectious disease

Pre-release screening programs in other species e.g., re-introduction

Approach…

Document the disease level in hatchery-reared larval population

Compare to disease level in wild larval populations

Document Disease Level:Hatchery All life stages:

Egg Larval Stages I - IV

Multiple production times Early summer Mid-summer Late-summer

Document Disease Level: Hatchery Tissue for histological examination

100 eggs/production cycle 100 of each larval stage/production cycle 50% examined, 50% stored as reference material

Stage III

Larval Histology

Findings: Surface Fouling (gills)

Mild to moderate Stage III

Stage IV

Husbandry?

Findings: Erosion & Ulceration

Mild Multifocal Stage II – IV

Trauma?

Findings Protozoan infection

mortality (1 tank, one cycle only)

Gills - primary site of infection

Mild to marked, inflammation with melanin

Protozoal Infection:Gill

Protozoal Infection:Gill

Findings Protozoan infection

mortality (1 tank, one cycle only) Gills - primary site of infection Mild to marked, inflammation with melanin

Stages III & IV affected, all production cycles

Opportunist? Food source - negative

Disease Findings: Summary

Lesion Early Summer

Mid-Summer

Late Summer

Surface Fouling

SIII SIII & SIV SIII & SIV

Erosion/Ulceration

SII – SIV SIII

MuscleDegeneration

SII SI – SIII SI

Parasite Migration

SIII & SIV

ProtozoalInfection

SIIISIII - mortality

SIII & SIV

SIV

Summary Documented conditions seen in one

hatchery environment

Primary pathogen or opportunistic?

Decreased overall production? Intervention strategies possible?

Risk to wild-hatched population? Naturally present?

Questions?

Findings: Muscle

Degeneration Mild to moderate Multifocal Stages I –III

Nutritional?Exertional?Normal??

Stage I

Findings Parasite Migration

Mild Muscle Hepatopancreas ± inflammation Stage III & IV

Off-course?? Stage IV