Starting a compilation on PS applicable to this thread.
Food of Three Species of Sunfishes
(Lepomis, Centrarchidae) and
Their Hybrids in Three
Minnesota Lakes •
DAVID A. ETNIER
TRANS. AMER. FISH. SOC., 1971, NO. 1
It is interesting
to note that hybrids between green sunfish
and pumpkinseeds from Sieverson and
Long Lakes agreed more closely with pumpkinseeds
than with bluegills in regard to the
consumption of Hyalella and snails, while the
Squaw Lake hybrids that were predominantly
between green sunfish and bluegill agreed
more closely with bluegill in this regard. Fish
were a rather insignificant food for hybrids,
but were more frequently ingested by hybrids
than by any of the parental species. A consistently
high percentage of hybrid stomachs
contained food (Table 4).
Transactions of the American Fisheries Society 116:98-102, 1987
Test of Genetic Differentiation in Growth of Stunted and
Nonstunted Populations of Yellow Perch and Pumpkinseed
DANIEL HEATH 1 AND DEREK A. ROFF 2
pumpkinseed
Lepomis gibbosus populations of Lac Hertel, Qu6-
bec.
Pumpkinseeds have been known to
be stunted since 1973 (W. C. Leggett, McGill University,
unpublished data), and again anecdotal
evidence suggestsa much longer period of stunting
Fish
The species of fish found in Lac Hertel include the following eight species:
northern pike (Esox lucius)
rock bass (Ambloplites rupestris)
yellow perch (Perca flavescens)
pumpkinseed sunfish (Lepomis gibbosus)
golden shiner (Notemigonus crysoleucas)
mudminnow (Umbra limi)
white sucker (Catostomus commersoni)
brown bullhead (Ictalurus nebulosis)
This is not the info I have previously read.
Vital Statistics of a Michigan Fish Population, with Special Emphasis on the Effectiveness of Stocking 15-cm Walleye Fingerlings
PERCY W. LAARMAN
North American Journal of Fisheries Management 1981;1:177–185
Mean total mortality rates of smallmouth bass (Micropterus dolomieui), bluegills (Lepomis macrochirus), pumpkinseeds (Lepomis gibbosus), and black crappie (Pomoxis nigromaculatus) were 60, 66, 72, and 58%,
MICHIGAN DEPARTMENT OF NATURAL RESOURCES
FISHERIES DIVISION
Redear Sunfish Management in Michigan
Gary L. Towns
Fisheries Technical Report 2003-3
September 30, 2003
http://www.michigandnr.com/PUBLICATIONS/PDFS/ifr/ifrlibra/technical/reports/2003-3tr.pdfAfter several years of observations, an
Indiana Department of Natural Resources,
fisheries biologist reported that redear sunfish
didn’t seem to “stunt” in growth like some other
panfish species (Neil Ledet, 1987, personnel
communication)
Some fisheries managers have speculated
that redear sunfish may out-compete native
panfishes in Michigan, especially pumpkinseed.
Redear sunfish and pumpkinseed both consume
snails. In fact, no other native fish species in
Michigan’s inland lakes uses snails as a primary
food item, so it is logical to assume that there
will be competition between these species. In
centrarchids, molariform teeth are present only
in redear sunfish and pumpkinseed (Trautman
1957), and mollusk-eating in centrarchids is
usually associated with increases in the
proportion of molariform teeth on the
pharyngeal jaws, among other things (Lauder
1983).
Huckins’ (1997) observations from a pond
competition experiment, and from fish surveys,
suggested that pumpkinseed and redear sunfish
compete, and that competition for snails is the
mechanism of the interaction. Redear sunfish
were superior to pumpkinseed in exploiting
snails. However, this study also suggested that
pumpkinseed may be better able to eat softbodied
prey items - such as aquatic insects.
Huckins’ analysis of pumpkinseed and redear
sunfish populations in two Michigan lakes (Lee
Lake, Calhoun County and Saubee Lake, Eaton
County) suggested the greater crushing strength
of redear sunfish allowed them to shift from a
diet of soft-bodied insects to a diet of snails at an
earlier age than pumpkinseed. Pumpkinseeds
≤2.6 in were consuming primarily soft-bodied
prey such as insect larvae, the bulk of which
were dipteran. Diets of larger pumpkinseeds
(≥2.6 in SL) also tended to be dominated by
chironomid larvae (about 37% of diet biomass),
with snails making up less of the diet (about
29% of the diet biomass). In contrast, Huckins
found redear sunfish in the same lakes showed a
striking shift in diet between small (<1.6 in SL)
and large individuals. Diets of small redear
sunfish contained approximately 30%-50% each
of snails and zooplankton, and the remainder
was dominated by dipteran larvae. Redear
sunfish larger than 1.6 in showed an extensive
shift to molluscivory - approximately 87% of the
average diet was composed of snails. It is
probable that where snails are prevalent the
superior snail crushing ability provides an
advantage to redear sunfish, but it is not so
overwhelming that pumpkinseed will likely be
extirpated after redear sunfish introductions.
Michigan fishery surveys have found
pumpkinseed populations co-existing with
redear sunfish in lakes that have had large redear
sunfish populations for several decades. Fish
populations in Lake George, Silver Lake, and
Coldwater Lake in Branch County and in
Crooked Lake in Washtenaw County are good
examples. Pumpkinseeds were present in most
recent trap net surveys of these lakes, but in low
numbers. In an effort to further examine this
issue, survey catch data for pumpkinseed were
examined in other lakes where redear sunfish
have been introduced (Table 5). In some
instances, specific pumpkinseed data were not
recorded in early (pre-redear sunfish
introduction) surveys. In other cases, redear
sunfish and pumpkinseed have co-existed for
only a few years, so long-term effects from any
competition could not be measured. However,
in most cases, where pumpkinseed survey data
exist, there seems to be no obvious negative
relationship. In 40 post-redear sunfish
introduction surveys, trap net catch-per-effort
(CPE) of pumpkinseeds decreased in 21
situations, increased in 18, and stayed the same
in 1. However, overall average pumpkinseed
CPE declined from 7.6 to 4.7. Total CPE of
redear sunfish and pumpkinseeds combined
increased in 36 of the 40 surveys.
Pumpkinseed growth index changes showed
no specific pattern after redear sunfish were
introduced. Adequate growth index data for
pumpkinseed (pre- and post-redear sunfish
introductions) were available for 9 lakes. Four
of these indicated that pumpkinseed growth
increased after redear sunfish were introduced,
four indicated decreased pumpkinseed growth,
and one was unchanged. The average of these
nine lakes was an increase in pumpkinseed
growth index from 0.2 to 0.3 in after redear
sunfish were introduced.
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