Fathead minnows in Europe: preliminary results

Fathead minnows in Europe:
preliminary results
Mr. Michael J. Godard (Cefas-Lowestoft)
J. Robert Britton (Bournemouth University)
Mr. Nicolas Guillerault (Cefas & Univ. F. Rabelais-Tours)
G. Zieba (Cefas-Lowestoft & Univ. of Łódź)
Gordon H. Copp (Cefas-Lowestoft & Bournemouth University)
Background
Fatheads in Europe
• Established in few countries compared to
other N.A. species (e.g. pumpkinseed):
• UK
• Holland*
• Belgium
• Germany?
• France?
*H. Verreycken
(pers. comm.)
Background
Fatheads in Europe
• Fatheads in Europe sold as a pet fish in
aquaria and garden ponds, mainly as ‘rosy
reds’
• Also used as experimental species and
possibly bait fish
• Linked to sudden appearance of Yersinia
ruckeri, the causative agent of enteric
redmouth disease*
*Michel et al. (1986) Bull. Eur. Assoc. Fish. Pathol. vol. 1986
Background
Fatheads in Europe
• Only known paper on feral populations in
Europe is from Flanders (Belgium) - 1st
record and morphology
Anseeuw et al. (2005) Belg J Zool vol. 135
Background
Fatheads in Europe
• In terms of predicted invasive-ness: lower
extent of high risk ranking (both UK &
Flanders)
• Limited distribution
in UK (previously in
garden ponds only)
Copp et al. (2009) Risk Analysis vol. 29
Vandenbergh (2007) PhD Thesis,
Katholieke Universiteit te Leuven.
Background
Fatheads in Europe
• However, most of the established NN
fishes in the UK are nest-guarders
• The current two most invasive fishes are
small-bodied, short-lived, nest guarding
cyprinids (P. parva, L. delineatus)
• Fathead minnow is also a small-bodied,
short-lived, nest guarding cyprinid…
Gozlan et al. (2003) Folia Zool vol. 52
Gozlan et al. (2010) Fish Fisheries (early view)
Study aim
Fatheads in England
Acquire basic biology for risk analy. process
• Sex ratio and pigmentation
• Morphology, age, growth and population
size structure
• Reproduction (fecundity, growth allocation
to gonads, length and age at maturity)
• Compare data with available information
within geographical & climatic context
Study area
Fatheads in England
• First wild-living pop. identified Aug. 2008 in
N. Yorkshire
photo: P. Stebbing
Study area
Fatheads in England
• First wild-living pop. identified Aug. 2008 in
N. Yorkshire
• Introduced as contaminant of golden orfe
(Leucicus idus) consignment ≈10 yrs earlier
photos: G.H. Copp
Study area
Fatheads in England
• Fatheads established in 2 of 5 ponds
(formerly a golden orfe rearing facility)
photo: M.J. Godard
Study area
Fatheads in England
• Fatheads established in 2 of 5 ponds
(former used to rear ornamental fish)
• In Oct.‘09, all 5 ponds combined into 1 pond
Study area
Fatheads in England
• Fatheads established in 2 of 5 ponds
(former used to rear ornamental fish)
• In Oct.‘09, all 5 ponds combined into 1 pond
• In early Feb.‘10 , we had to rescue live
specimens (≈500) for future research
Study area
Fatheads in England
• Fatheads established in 2 of 5 ponds
(former used to rear ornamental fish)
• In Oct.‘09, all 5 ponds combined into 1 pond
• In early Feb.‘10 , we had to rescue live
specimens (≈500) for future research
• Population eradicated with rotenone in midFeb. 2010 by Environment Agency despite
very low risk of dispersal & our on-going
research
Sampling
Fatheads in England
• Sampling undertaken monthly May to
December 2009
• Used minnow traps
(baited with Polish bread)
• Overnight exposure
photo: M.J. Godard
Sex ratio
Fatheads in England
• Ratios (M/F) deviate from parity
• Females predominate in both ponds
0.66
0.45
Pigmentation (ornamental)
Fatheads in England
• Rosy red variety arose from genetic
mutation, with ≈ 20% of populations
expected to be of red variety
Morphology, age, growth etc.
Fatheads in England
• Morphology1 and
age2 still being
processed
1V.
Kováč team
Britton
2J.R.
Growth & Size structure
Fatheads in England
• Morphology and
age still being
processed
• Based on native
range, variations
in growth and lifehistory between
populations to be
expected
*Danylchuk & Tonn (2006) J Fish Biol vol. 68
Age, Growth & Size structure
Fatheads in England
• English pop. size structure (at capture)
• No diff. in mean total length between ponds
Large pond
Small pond
Reproduction – fecundity
Fatheads in England
• No difference in mean egg size in ponds
(both about 0.64 mm diameter)
Reproduction – fecundity
Fatheads in England
• No difference in mean egg size in ponds
(both about 0.64 mm diameter)
• Low absolute fecundity (eggs/fish):
Large pond England =
27 to 973
Small pond England =
18 to 585
From exp. conditions = 1100 to 2100*
*Tillitt et al. (2010) Aquatic Toxicology vol. 99
Reproduction – fecundity
Fatheads in England
• No difference in mean egg size in ponds
(both about 0.64 mm diameter)
• Low absolute fecundity
• Low mean no. eggs/fish:
Large pond England =
397
Small pond England =
259
From exp. conditions = 1200*
*Thorpe et al. (2009) Environ Sci Technol vol. 43
Growth allocation
Fatheads in England
• In our large pond:
• Relative fecundity
decreased with
increasing fish
length (not seen in
small pond)
Growth allocation
Fatheads in England
• In our large pond:
• Relative fecundity
decreased with
increasing fish
length (not seen in
small pond)
• Greater female
allocation to
reproduction (at
smaller sizes)
Males
Growth allocation
Fatheads in England
• In our large pond:
• Greater female
allocation to
reproduction (at
smaller sizes)
• Exp. conditions*,
mean GSIs were:
females =12.1
males=1.25
Males
*Villeneuve et al. (2010) Ecotoxicol Environ Safety vol. 73
Length & age at maturity
Fatheads in England
• Can reach maturity and spawn in first year1
1Held
& Peterka (1973) Trans Amer Fish Soc vol. 103
1Markus (1934) Copeia vol. 1934
Length & age at maturity
Fatheads in England
• Can reach maturity and spawn in first year1
• This may be happening in the small pond,
where very small size at maturity observed:
• Large pond = 46.3 mm TL (higher density)
• Small pond = 36.4 mm TL (lower density)
1Held
& Peterka (1973) Trans Amer Fish Soc vol. 103
1Markus (1934) Copeia vol. 1934
Length & age at maturity
Fatheads in England
• Can reach maturity and spawn in first year1
• This may be happening in the small pond,
where very small size at maturity observed:
• Large pond = 46.3 mm TL (higher density)
• Small pond = 36.4 mm TL (lower density)
• But, probably requires a longer, warmer
summer2 than is typical of England
• To be re-examined when ageing completed
1Held
& Peterka (1973) Trans Amer Fish Soc vol. 103
1Markus (1934) Copeia vol. 1934
2Divino & Tonn (2007) Ecol Freshwat Fish vol. 16
Summary
Fatheads in England
• There is currently NO comparable data from
any of the other feral populations of fathead
minnow in Europe
Summary
Fatheads in England
• There is currently NO comparable data from
any of the other feral populations of fathead
minnow in Europe
• The similar size structure of the populations
is consistent with an absence of piscivorous
fishes*
*Duffy (1998) Can J Fish Aquat Sci vol. 54
Summary
Fatheads in England
• There is currently NO comparable data from
any of the other feral populations of fathead
minnow in Europe
• The similar size structure of the populations
is consistent with an absence of piscivorous
fishes
• Whereas, the shorter length at maturity in
the small pond may be linked to the lower
fathead densities observed
Summary
Fatheads in England
• Rapid maturation & reproduction, and the
apparent life-history plasticity of the feral
fatheads (suggesting a higher invasiveness
risk than indicated by previous RAs)
Summary
Fatheads in England
• Rapid maturation & reproduction, and the
apparent life-history plasticity of the feral
fatheads (suggesting a higher invasiveness
risk than indicated by previous RAs)
• Data from native range suggests this
requires a long 1st year vegetative season,
which does not match the current (benign)
UK climate
Summary
Fatheads in England
• However, our recent modelling work
identified fathead minnow as 1 of 6 species
in the UK expected to benefit from climate
warming (by 2050)
Britton et al. (2010) Freshwat Biol vol. 55
Summary
Fatheads in England
• However, our recent modelling work
identified fathead minnow as 1 of 6 species
in the UK expected to benefit from climate
warming (by 2050)
• This suggests fathead minnows could
become invasive within next 40 years, so
further research needed, with control and/or
eradication in areas of elevated risk of
dispersal into open waters
Future work
Fatheads in England
• Plans for establishment of new populations
in six artificial ponds (5x5 m) in southern
England
• Comparison of growth and life-history traits
in newly introduced populations in these
English ponds and in part of species’ native
range (Ontario, Canada)
Future work
Fatheads in England
• Plans for establishment of new populations
in six artificial ponds (5x5 m) in southern
England
• Comparison of growth and life-history traits
in newly introduced populations in these
English ponds and in part of species’ native
range (Ontario, Canada)
• Consideration of climate change effects
• Hopefully data from other European sites
Acknowledgements
Many thanks to the Fisheries Society of the
British Isles for sponsoring my attendance
at this conference
Acknowledgements
Many thanks to the Fisheries Society of the
British Isles for sponsoring my attendance
and to the funding bodies: UK Defra,
European Commission
& Questions