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Abundance of Cottus poecilopus is influenced by O2 saturation, food density and Salmo trutta in three tributaries of the Rožnovská Bečva River, Czech Republic


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The distribution patterns of alpine bullhead Cottus poecilopus in three tributary streams of the Rožnovská Bečva River (Danube basin) were studied with respect to temperature, oxygen concentration and saturation, shading, current, conductivity, total organic carbon (TOC), nitrates and phosphates, biochemical oxygen demand (BOD5), pH, redox potential, bottom grain structure, density of macroinvertebrates and the abundance of brown trout Salmo trutta. Sites with lower abundance per hectare of C. poecilopus differed significantly in dissolved oxygen saturation, density of macroinvertebrates during the autumn period (positive correlation with C. poecilopus) and in abundance per hectare of S. trutta (negative correlation). These results indicate that these factors significantly influence the distribution of this endangered species in the studied catchment and that stocking of S. trutta will impair its recovery.
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Journal of Fish Biology (2015) 86, 805811
doi:10.1111/jfb.12565, available online at
Abundance of Cottus poecilopus is inuenced by O2
saturation, food density and Salmo trutta in three tributaries
of the Rožnovská Beˇ
cva River, Czech Republic
R. B*, J. K*, M. K§, B. L¶, T. M
D. R*  M. R§
*Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Hydrobiology,
Na Sádkách 7, 370 05, ˇ
Ceské Budˇ
ejovice, Czech Republic, Faculty of Science, University of
South Bohemia, Branišovská 31, 370 05, ˇ
Ceské Budˇ
ejovice, Czech Republic, §Department of
Ecology and Environmental Sciences, Faculty of Science, Palack´
y University in Olomouc,
u 11, 783 71, Olomouc, Czech Republic, Správa CHKO Beskydy, Nádražní 36, 756
61, Rožnov pod Radhoštˇ
em, Czech Republic, Faculty of Science, Ostrava University, 30.
Dubna 22, 701 03, Ostrava, Czech Republic and **Faculty of Economics, University of
South Bohemia, Studentská 13, ˇ
Ceské Budˇ
ejovice, Czech Republic
(Received 30 July 2014, Accepted 26 September 2014)
The distribution patterns of alpine bullhead Cottus poecilopus in three tributary streams of the
Rožnovská Beˇ
cva River (Danube basin) were studied with respect to temperature, oxygen con-
centration and saturation, shading, current, conductivity, total organic carbon (TOC), nitrates and
phosphates, biochemical oxygen demand (BOD5), pH, redox potential, bottom grain structure,
density of macroinvertebrates and the abundance of brown trout Salmo trutta. Sites with lower
abundance per hectare of C. poecilopus differed signicantly in dissolved oxygen saturation, density
of macroinvertebrates during the autumn period (positive correlation with C. poecilopus)andin
abundance per hectare of S. trutta (negative correlation). These results indicate that these factors
signicantly inuence the distribution of this endangered species in the studied catchment and that
stocking of S. trutta will impair its recovery.
© 2014 The Fisheries Society of the British Isles
Key words: Alpine bullhead; brown trout; macroinvertebrates; organic carbon; shading; water temper-
Alpine bullhead Cottus poecilopus Heckel 1837 inhabits European mountain streams.
Its main areas are Scandinavia and the Baltic region, and the Carpathian Mountains
(Kottelat & Freyhof, 2007). In the Czech Republic, C. poecilopus is limited to the Odra
River (Baltic Sea basin) and Morava River (Black Sea basin) drainages. In this coun-
try, the ecologically similar, close relative bullhead Cottus gobio L. 1758 occurs in the
Elbe River (North Sea basin) (Starmach, 1965; ˇ
r, 1969). Cottus poecilopus often
coexists with brown trout Salmo trutta L. 1758 in well-oxygenated mountain streams
Author to whom correspondence should be addressed. Tel.: +420387775891; email:
© 2014 The Fisheries Society of the British Isles
012345 kmZákopecký stream
Solanecký stream
Roznovská Becva
Czech Republic
F. 1. Study area and location ( ) in the Czech Republic (VE, Vermíˇ
rovskýstream; ST, Starozuberskýstream;
ZA, Zákopeckýstream).
(Lusk et al., 2008) and is categorized as being of least concern on the European red list
(Freyhof & Brooks, 2011) while in the Czech Republic it is categorized as near threat-
ened (Lusk et al., 2011). Cottus poecilopus is adapted to a narrow range of conditions,
and can therefore be considered a bio-indicator species (Hanel & Lusk, 2005). In the
Czech Republic, the occurrence of C. poecilopus is limited to clear unpolluted streams
as they are particularly sensitive to water temperature and dissolved oxygen concen-
trations. The aim of this study is to investigate the inuence of physical and chemical
factors on C. poecilopus and to identify the main determinants of its abundance.
Cottus poecilopus were sampled in three tributaries of the Rožnovská Beˇ
cva River
(the Vermíˇ
y, Starozubersk´
y and Zákopeck´
y streams) in October 2010 (Fig. 1).
Electroshing was performed in eight 100 m long sections, three sections located in
each of the Vermíˇ
y and Starozubersk´
y streams and two in the Zákopeck´
y stream
(Table I). Mean width varied between 36 and 43 m. The water depth was measured
with a calibrated bar at 10 sites in each section and the average depth was calculated.
Before sampling, the study sections were screened off with a 5 mm bar mesh net. This
prevented the sh from escaping. Each section was sampled twice, 1 h apart, in the
upstream direction with a battery electroshing device SEN 8 A, 192– 423 V(manu-
factured by Bednáˇ
r; and two catches were conducted in each
section. As the smallest individuals are very difcult to catch, only C. poecilopus 1
year and older and total length >40 mm were sampled. Fish abundance (number of sh
ha1) was calculated for each sampling event and the overall abundance estimate was
determined using the two-catch method of Seber & LeCren (1967).
The middle part of each section was marked and physical and chemical vari-
ables of water (temperature, dissolved oxygen, oxygen saturation, pH, conductivity,
redox potential and current) were measured on the day of sampling, and every
month from October 2010 to September 2011. Water temperature was measured
in the shade at a depth of c. 10 cm away from the main stream ow. Temperature,
© 2014 The Fisheries Society of the British Isles, Journal of Fish Biology 2015, 86, 805–811
T I. Basic characteristics of each sampled river section, mean ±.. of oxygen saturation, abundance of macroinvertebrates in autumn (Ma) and
in spring (Ms), mean ±.. of Cottus poecilopus (Cp) and Salmo trutta (St) total length (LT), captured numbers and calculated sh per hectare
saturation (%)
(n100 m1)
(n100 m1)
VE1 08259667 ±1361 834 2168 0 ±0 148 ±30 0 122 0 3050
VE2 2140 10000 ±1250 1445 2525 80 ±18 106 ±20 9 131 215 3119
VE3 3165 10025 ±1113 2094 2223 70 ±10 118 ±30 90 38 2093 884
ST1 07259742 ±1092 584 2102 0 ±0 128 ±16 0 88 0 2200
ST2 2630 10050 ±1383 1602 1119 77 ±9 116 ±27 11 114 262 2715
ST3 3850 10033 ±1256 897 1614 82 ±14 119 ±25 27 14 750 389
ZA1 0925 10083 ±1094 1792 3940 80 ±20 147 ±20 83 40 1977 953
ZA2 1850 10183 ±1075 1312 3143 90 ±11 117 ±29 50 53 1163 1233
n, number; VE, Vermíˇ
rovskýstream; ST, Starozuberskýstream; ZA, Zákopeckýstream.
© 2014 The Fisheries Society of the British Isles, Journal of Fish Biology 2015, 86, 805–811
pH and redox potential were measured using a Greisinger GHM 3530 portable
multimeter ( Dissolved oxygen content and oxygen
saturation were measured by a Hanna Oxy-check dissolved oxygen meter, and
temperature-compensated conductivity was determined by a Hanna DIST3 conductiv-
ity meter ( A Flo-mate 2200 owmeter (www.
was used to measure current velocity at three points in the main stream ow of each
section. Total organic carbon (TOC) was measured by Pt-catalysed high-temperature
combustion on a Formacs analyser (Skalar Analytical; Determina-
tion of nitrates and phosphates was done on mixed water samples taken from each
section. To prevent further microbial decomposition, 15 ml of chloroform CHCl3was
added to the sample. A Dr 2000 spectrophotometer (Hach Company;
was used to analyse nitrate and phosphate levels. Determination of biochemical
oxygen demand (BOD5) was made during August 2011 using an OxiTop Control 6
BOD respirometer system (Wissenschaftlich-Technische Werkstätten;
Macroinvertebrate sampling was performed during the autumn (October 2010) and
spring (April 2011). A metal frame benthic net with a mesh size of 500 μm and an area
of 1089 cm2was used for quantitative sampling of macroinvertebrates at three points
of each stream section. The macroinvertebrates were preserved in a 4% formaldehyde
solution. Macroinvertebrates were identied to family level and density was expressed
as number m2. Three samples of the bottom substratum were taken in each section
in July 2011 with a metal shovel. After drying, sediment samples were sieved through
mesh sizes 20, 10, 7, 3, 07, 04, 009 and 0083 mm. All grain size fractions were
weighed and the per cent mass of each size was calculated.
The abundance ha1of C. poecilopus was log10(x+1) transformed prior to the anal-
ysis to ensure the normality of data. Forward stepwise regression was used to choose
appropriate explanatory variables. Because of the low number of data points, the
Akaike information criterion (AIC) (R Core Team; did not reach
its minimum value before a total t was achieved (a total t corresponds to using all of
the seven available variables). Therefore, the chosen criterion was that the increase in
r2with each added variable needed to be at least 3%. These revised stepwise analyses
were conducted in Statistica 10 (Statsoft Inc.;
The abundance of C. poecilopus (Y, numbers ha1) increased with the O2saturation
(XO,%;r2=089), increased with density of macroinvertebrates with autumn (XM,
numbers m2;r2=094) as a second predictor variable and decreased with density
of S. trutta as a third predictor variable (XS, numbers ha1;r2=098) (Table I). The
correlations between C. poecilopus abundance and each of these factors are shown
in Fig. 2 and the full model is Y=−414400 +04579XO+00010XM10622XS
(F3,4 =10303, P<0001). The other factors were not signicantly correlated with C.
poecilopus abundance and not included in the model.
The lowest limit of oxygen saturation tolerated by C. gobio is 74% (Legalle et al.,
2008). ˇ
r (1969) reported a higher oxygen requirement for C. poecilopus and this
may be the reason why this species occupies higher altitude sites than C. gobio in
the Carpathian Mountains. There were no, or very limited, local sources of pollution
in the area studied, and the values of BOD5and TOC indicated good water quality.
The observed variations in oxygen saturation observed along the 1– 3 km long stream
sections were sufcient, however, to inuence the distribution of C. poecilopus during
its seasonal cycles, particularly in summer.
© 2014 The Fisheries Society of the British Isles, Journal of Fish Biology 2015, 86, 805–811
Oxygen saturation (%)
Macroinvertebrates (XM m
96 97 9899 100 101 102 103
400 600 800 1000 1200 1400 1600 1800 2000 2200
2·6 2·83·0 3·2 3·4 3·6 3·8
Log10 number of
Salmo trutta
(n + 1) of Cottus poecilopus
F. 2. Log10 (n+1) of Cottus poecilopus ha1(Y) on (a) oxygen saturation (XO)(Y=−78531 +0811XO;
r2=0899, t=803, d.f. =6, P<0001), (b) density of macroinvertebrates in autumn (XMm2)
(Y=−0835 +00024XM;r2=06394, t=383, d.f. =6, P<001) and (c) number of Salmo trutta ha1
(log10 XS)(Y=87255 19057XS;r2=01884, t=−304, d.f. =6, P<005). 95% .. are given ( ).
The dominant families of macroinvertebrates found in all the sampled sections were
Gammaridae, Heptagenidae, Baetidae, Elmidae, Chironomidae and Leuctridae. The
abundance of autumn macroinvertebrates in all sections was within an order of mag-
nitude of that reported in the spring (Table I). Higher temperatures may speed up the
emergence of adult insects and result in the lower abundance found in warmer sections.
© 2014 The Fisheries Society of the British Isles, Journal of Fish Biology 2015, 86, 805–811
This was reported by Vannote & Sweeney (1980) and Marten & Zwick (1989). The pre-
ferred diet of C. poecilopus is usually Chironomidae, Ephemeroptera and Trichoptera
larvae (Holmen et al., 2003; Hesthagen et al., 2011).
The abundance ha1of C. poecilopus showed an inverse relationship with the abun-
dance ha1of S. trutta. While Lusk et al. (2009) assumed that shery management
does not have a signicant effect on C. poecilopus, the present data suggest a negative
inuence from the S. trutta stocking that occurs in this river. A dense S. trutta popula-
tion in the investigated streams has been supported by the angling association, which
periodically stocks and harvests S. trutta in 2 year cycles. Over 75% of S. trutta were
age 2+years. Both C. poecilopus and S. trutta appeared to prefer the most productive
parts of the mountain streams where they may compete for food when their popula-
tion density is high (Hesthagen & Heggenes, 2003). In Norway, an 80% diet overlap
was found between C. poecilopus and S. trutta (Hesthagen et al., 2004) and the newest
observations of Louhi et al. (2014) suggest a negative effect of young S. trutta on C.
Thus, C. poecilopus occurs in streams with high oxygen saturation and high abun-
dance of macroinvertebrates, but appears to avoid areas with a high density of S. trutta.
The other factors studied appeared have minor inuence on the distribution of C. poe-
cilopus in the study streams. Salmo trutta stocking can hence have a negative effect on
the occurrence and distribution of this rare sh species.
We would like to thank E. Tošenovsk´
y, V. Uvíra and the Palack´
y University in Olomouc
for providing eld and technical assistance and T. J˚
uza and J. Matˇ
ena for help writing the
manuscript. L. Tse kindly corrected the English. We are grateful to anonymous reviewers and
assistant editor of Journal of Fish Biology for helpful suggestions. The study was supported by
the project 181 145/2013/P of the Grant Agency of the University of South Bohemia.
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... Bullheads are characterized by sedentary behavior (Reyjol et al. 2009) that allows for the assessment of local environmental disturbances (Jolly et al. 2012). It was found that these fish avoid habitats with a high density of brown trout (Salmo trutta) (Baran et al. 2015). In the Tatra mountains, the most numerous populations were recorded at altitudes between 911 and 979 m a.s.l. ...
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Skulls of alpine bullhead sampled from the Javorinka stream in the Tatra Mountains, West Carpathians, were analyzed to determine concentrations of S, Cl, K, Ca, P, Rb, Zn, Mn, Mb, Fe, Ti, Sn, Co, Ni, Cu, As, Se, Pb, Sb, Ba, Hg, Cr, Ag, and Cd. The stage of development is the most influential factor determining element concentrations in the sampled bullhead, as fry were more polluted than adult fish. The different diets consumed by fry and adult bullhead plays a key role in the accumulation of chemical elements in their bodies. Young bullheads live in small natural embankments containing higher levels of a mixture of sedimentary minerals and microorganisms than in running water. Thus, newly hatched bullheads may serve as excellent indicators of water quality in mountain creeks or streams, as they can indicate the higher pollution of water or prey in their habitats (small bays with sandy bottoms) when compared to the preferred habitat of adult individuals.
... The cold water fish Cottus poecilopus was also reported to be abundant in streams with high oxygen saturation and high abundance of macroinvertebrates (Baran et al., 2015). Another study of aquatic organisms found that among-pond variation in community structure of freshwater zooplankton was partially explained by pH and dissolved oxygen (HolmesSingh, 2016). ...
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... Stocking hatchery brown trout is known to have a negative impact on the growth and survival of various stream dwelling species (Buoro, Olden, & Cucherousset, 2016). Alpine bullhead are less abundant at sites with a high abundance of S. trutta (Baran et al., 2014). However, the effect of habitat degradation and trout stocking on the capacity of Alpine bullhead populations to resist natural disturbances like flash floods has not been addressed. ...
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The density, diet and habitat use of brown trout (Salmo trutta) and Siberian sculpin (Cottus poecilopus) were studied in the subalpine River Atna in southeastern Norway in the autumn during a six year period (1986–1991). There was an inverse relationship between the density of brown trout and Siberian sculpin. Diet overlap, as indicated by the Schoener index, was high between the two species, ranging between 0.48 and 0.86. Chironomid larvae and other aquatic insects were the most common food items for both species. Brown trout also consumed substantive amounts of surface insects. Siberian sculpin typically occupied sites with finer substrates and greater water depths than brown trout, even though there was considerable overlap in habitat use between the two species. Because the two species shared similar habitats, we suggest that the potential for species interactions exists, particularly at sites where density of sculpin is high.
Where two successive catches, c1 and c2 are taken with the same effort from a population, an estimate of the size of the population, ñ, is given by $\tilde{n}=c_{1}{}^{2}/(c_{1}-c_{2})$ , with a variance ${\rm var}\ [\tilde{n}]=[c_{1}{}^{2}c_{2}{}^{2}(c_{1}+c_{2})]/(c_{1}-c_{2})^{4}$ Estimates from more than two successive catches, from single catches and of mortality rates are discussed and formulae given. Simple mark-recapture experiments can be combined with repeated catch experiments.
Stream-dwelling salmonids and bullheads occupy similar resource niches in northern rivers. It is therefore tempting to assume that they might be involved in a competitive interaction, with potential implications for the habitat use and growth of brown trout (Salmo trutta). We conducted artificial-stream experiments to test whether a putative competitor, Alpine bullhead (Cottus poecilopus), had an effect on the habitat use of under-yearling (0+) and yearling (1+) trout. We hypothesised that (i) 1+ trout would be competitively superior to 0+ trout, forcing the younger fish to suboptimal habitats, and that (ii) bullhead might affect the habitat use and prey selection of 0+ trout but less so that of 1+ trout. Against our predictions, no effect of bullhead was found on the habitat use of either age class of brown trout. Instead, yearling trout seemed to force bullheads to suboptimal microhabitats with high current velocities. Presence of yearlings also decreased the growth of under-yearling fish and caused a shift in their diet composition. These findings suggest that competitive interactions may not limit the coexistence of brown trout and bullheads in boreal rivers. Intraspecific interactions between trout age classes may be more important, with potentially detrimental effects on the growth and overwintering success of 0+ trout.
Adult body size and fecundity of several species of hemimetabolous aquatic insects were shown to depend largely on thermal conditions during larval growth. We suggest that an "optimum" thermal regime exists where adult size and fecundity are maximized; temperature regimes warmer or cooler than the "optimum'' result in small and less fecund adults. Two hypotheses concerning river water temperatures and size variation of adult insects are described. First, maximum adult size reflects an equilibrium between several developmental processes that appear highly temperature dependent, viz., (i) the rate and duration of larval growth, and (ii) the specific time in larval development that adult structures begin maturing and the rate of this maturation process. Second, a species distribution both locally within drainage systems and over a large geographic area is limited, in part, by lowered fecundity as adult size gradually diminishes in streams of increasingly cold or warm temperature cycles. The importance of riv...
1. Egg development and larval growth of Protonemura intricata (Ris, 1902) (Plecoptera: Nemouridae) were studied in the laboratory and in the Breitenbach, a small stream-in Germany (F.R.G.). 2. The mean number of eggs in batches collected from the field was 627 (S=314). 3. Mean batching success in the laboratory was 60–100% at 2–18°C. Cumulative hatch in individual batches could be described by asymmetrically sigmoid curves. The length of the hatching period was positively correlated with the length of the incubation period. 4. The incubation period of I', intricata normally consists of an initial dormancy followed by subsequent development. The length of embryonic development (Y. days) is strongly inversely temperature (T, °C) dependent and can be described by the equation: 5. The length of dormancy is dependent on oviposition dale, and is shorter the later that the eggs are laid. It also depends on temperature during incubation and is increased by rising temperatures. As a consequence, larvae hatch more or less synchronously in the field during autumn. Total incubation period, i.e. dormancy and actual development, exhibits a complex dependence on both incubation temperature and oviposition date. Under constant laboratory temperatures, a late sharp fall in temperature can terminate dormancy earlier. 6. Photoperiod probably induces dormancy and may already act on the last larval instars of the parent generation. The dormancy of P. intricata is classified as an oligopause (Müller. 1970, 1976). 7. In the laboratory. P. intricata larvae from early batches with long dormancy grew faster than larvae from late batches with direct development. Final size was the same in both cases. This acted against the population synchrony induced through egg dormancy. Benthos samples suggest the same in the field. 8. Avoidance of the suboptimal summer conditions in streams by the cold stenothermous P. intricata is suggested to partly explain the success of the species, which contributes more to total emergence biomass than do other Plecoptera in the Breitenbach.
Habitat competition in brown trout Salmo trutta and Siberian sculpin Cottus poecilopus was investigated by varying density, fish size, and species composition in stream channels providing areas of different substratum particle sizes. In allopatry, both small (52 ± 4 mm LT) and large (86 ± 6 mm LT) brown trout exhibited strong preference for the intermediate (8–11 cm diameter) and large (17–21 cm) gravel substrata. There was a tendency for more brown trout to occupy finer (2–4 cm) substrata with increasing density, in particular for large brown trout. Also, more small brown trout were observed on finer substrata when tested with large brown trout, suggesting interspecific competition for restricted space. Both small (56 ± 6 mm LT) and large (88 ± 10 mm LT) Siberian sculpin preferred the large gravel in all tests, and did not change their substratum preferences much with increasing densities, suggesting higher tolerance for ‘crowding’. The large Siberian sculpin preferred the coarser substratum, and the largest individuals were consistently found on it. In sympatry with large Siberian sculpin, habitat displacement of brown trout occurred, indicative of interspecific competition. A higher proportion of small and large brown trout occupied the finer substrata than in allopatry. Habitat selection by large Siberian sculpin appeared to be unaffected by species composition and density. Small Siberian sculpin were displaced to finer substrata when tested with large Siberian sculpin, suggesting intraspecific competition. The results indicate that Siberian sculpin are potential habitat competitors for young brown trout.