02_Afanasyev-1.indd UDC 595.384.1(497.6) NEW FINDINGS OF WHITE CLAWED CRAYFISH, AUSTROPOTAMOBIUS PALLIPES (DECAPODA, ASTACIDAE), AND PECULIARITIES OF ITS SPATIAL DISTRIBUTION IN NERETVICA (BOSNIA AND HERZEGOVINA) S. Afanasyev1, O. Lietytska1, O. Golub1, O. Iarochevitch2, K. Mudra2, O. Marushevska2 1Institute of Hydrobiology of NAS of Ukraine, Geroev Stalingrad, 12, Kyiv, 04210 Ukraine E-mail: safanasyev@ukr.net E-mail: lietitska@ukr.net E-mail: oleggolyb@gmail.com 2Blue Rivers® Environmental Consulting, Pushkinska st., 12 b, offi ce 30, Kyiv, 01001 Ukraine E-mail: iaralex@ukr.net E-mail: kmydra@i.ua E-mail: olena.marushevska@gmail.com S. Afanasyev (https://orcid.org/0000-0002-5247-3542) O. Lietytska (https://orcid.org/0000-0001-7026-4093) New Findings of White Clawed Crayfi sh, Austropotamobius pallipes (Decapoda, Astacidae), and Peculiarities of its Spatial Distribution in Neretvica (Bosnia and Herzegovina). Afanasyev, S., Lietitska, O., Golub, O., Iarochevitch, O., Mudra, K., Marushevska, O.  — At the territory of Bosnia and Herzegovina Austropotamobius pallipes (Lereboullet, 1858) is present mainly in the Neretva basin, partly in the Una and Tsetina river basins (Trožić-Borovac et al., 2012). Th is species was registered at elevations from 180 to 1024 m a. s. l., but most habitats are located at elevations from 300 to 600 m a. s. l. Based on indirect data, one can state that more than 2/3 of the crayfi sh population in the Neretva basin is concentrated in the Neretvica basin. Our studies showed that the crayfi sh are very irregularly distributed in the Neretvica basin. Th e crayfi sh are almost absent at well-fl ushed habitats without CPOM (deposits of coarse particulate organic matter, e. g., fallen leaves), as well as at habitats with monotonous boulders or gravel-sand bottom. Th e study of the size structure of the crayfi sh population showed the presence of juvenile crayfi sh with a size of less than 5 cm in the Neretvica River course. Th e most balanced structure of the crayfi sh population represented by juvenile as well as adult species is observed in Gorovnik. K e y w o r d s : Austropotamobius pallipes, habitats, spatial distribution, Neretvica, Neretva (Bosnia and Herzegovina). Zoodiversity, 55(4): 285–294, 2021 DOI 10.15407/zoo2021.04.285 286 S. Afanasyev, O. Lietytska, O. Golub, O. Iarochevitch, K. Mudra, O. Marushevska Introduction White clawed crayfi sh, Austropotamobius pallipes (Lereboullet, 1858), is the most ancient species in the family Astacidae. In Miocene, this species had a wide distribution throughout Europe (Maguire, 2002; Maguire et al., 2004). At present, its habitats got decreased. At present the western boundary of the species distribution has shift ed from Portugal to north-western Spain; northern one — to Scotland, southern one — to Spain, and eastern ones — to Austria and Montenegro. Th eir habitats are decreased in Austria, Corsica, Germany, Lich- tenstein, and Montenegro. It is expected that during the last 10–15 years in Great Britain, France, and Italy, the abundance of this species has decreased by 50–80 % (Souty-Grosset et al., 2006). It has been assessed by IUCN as “endangered” under criterion A2ce. Th is species has been listed under the EU Habitats Directive Annex II and V and therefore requires the designation of special areas of conservation for its protection. It has also been listed under Appendix III of the Bern Convention. Despite its protected status, the biological, ecological, abundance, and diversity of this species is not well-studied. For Bosnia and Herzegovina, there are only a few studies: Entz, 1914; Karaman, 1929, 1963; Šandra and Petrusek, 2008; Trožić-Borovac, 2011; Trožić-Borovac et al., 2012. Th ere is insuffi cient knowledge to understand the biology, behavioral patterns, feeding and habitats of the crayfi sh, their role in the river eco- system, what is needed to develop a program of measures Fig. 1. Map of the research area. 287New Findings of White Clawed Crayfi sh, Austropotamobius pallipes (Decapoda, Astacidae)… Material and methods A study of the distribution of the white-clawed crayfi sh, Austropotamobius pallipes (Lereboullet, 1858), was conducted in the Neretvica River basin in August 2016, May and September 2017 in the frame of complex studies of water fauna of this river in connection with its possible regulation for hydropower needs (fi g. 1). Th e Neretvica is a river in  Bosnia and Herzegovina which has a source on the slopes of Zec mountain at the altitude of 1792 m. Th e river fl ows into Jablanicko Lake (a large water reservoir formed at the Neretva River). Th e Neretvica is a right tributary of the Neretva River. Th e length of the river is 27 km; the catchment area is around 136 km2 (in hydrological station Gorani). Th e average elevation of the river catchment is 376 m above sea level. Th e river valley is U-shaped of the most part its length. U-shaped valley is typical for the lower course of the Neretvica. A single type of channel is typical for most parts of the river. In several places, river channel is braided, but its total length is insignifi cant. Th ere are much wood debris (both trunk and brushwood) in the river channel from very upstream up to the mouth. Th e four largest tributaries  — Obascica, Prolaz, Mala Neretvica, Crni Potok  — enter Neretvica in its middle course, and one tributary — Gorovnik enter in the lower course. As far as there is a defi cit of data about the ecology of this rare species and its habitat preferences, the study was done using the screening method of the maximum number of microhabitats. Th e study was done using scuba diving and special crayfi sh traps with baits, placed in identifi ed and potential crayfi sh habitats. Besides, the crayfi sh were registered using investigatory fi sh catches using electrofi shing based on the BiH permit DOZ- VOLU Federal Ministry of Agriculture, Water Management and Forestry Bosnia & Hercegovina 03-3-24/3- 970/17 A.S. 04.05.2017. Th e following parameters were measured using a metal ruler: total (zoological) length, length of carapace, a width of a carapace in the widest place, and its weight. Th e total number of the measured crayfi sh was 25. Besides, 7 dead crayfi sh were measured. Moreover, more than 20 specimens were observed in nature. Th e caught crayfi sh were tagged using notching at the carapace (Rumyantsev, 1970). Aft er measurements, the caught crayfi sh were released using accurate dorsiventral diving to avoid having air bubbles under the carapace. Results of study For the fi rst time Austropotamobius pallipes was found in Neretvica basin during the spring survey of 2016 during scuba diving observation of mouths of tributaries of Gorovnik (fi g. 1, point 1) and Crni Potok (fi g. 1, point 2). Only two specimens were caught in the habitats outside of the main course. Th ese habitats are characterized by the accumulation of fi ne and middle-size fractions of sand and gravel with a signifi cant share of organic detritus. Besides, during the visual survey of the main course of Neretvica downstream of the Crni Potok one dead crayfi sh was found (fi g. 1, point 3), and during the survey of the riparian zone near Podhum 1 (fi g. 2, area 1) the remains of one more specimen were found. In traps placed in deep spots along the main course of the Neretvica from Prolaz tributary till the mouth, the crayfi sh were not found. A study using the electrofi shing conducted during May–September 2017 along the whole river and its tributaries allowed the identifi cation of peculiarities of the crayfi sh distribution in the Neretvica river basin. It showed that the crayfi sh are distributed ir- regularly. Th e maximum elevation above the sea level, where the crayfi sh were found (one dead specimen) was 918 m a. s. l. Th e fi rst location starting from the river source, where signifi - cant concentrations of the crayfi sh were found was in the mouth of Prolaz Rver (coordi- nates 43 49´56.3˝ N 17 52´58.3˝ E) (fi g. 1, point 4). Th e average elevation is 753 m a. s. l. It is located 11 km downstream from the source. Th e form of the valley is U-shaped. Th e riverbed type is classifi ed as a single channel type. Flow types are turbulent, broken stand- ing waves, unbroken standing waves, and rippled. Th e average width of Prolaz was 2.5 m and varied from 1.1 to 3.5 m. Bed elements included bars, rocks, and step/pools. Th e average depth of Prolaz was 0.15 m, with a maximum of 0.25 m. Th e average velocity of Prolaz was 0.2 m/s, with a maximum of 0.6 m/s (fi gs 2, 3). 288 S. Afanasyev, O. Lietytska, O. Golub, O. Iarochevitch, K. Mudra, O. Marushevska Distribution of bottom habitats in the places of the crayfi sh catch: megalithal  — 30  %, macrolithal  — 20  %, me-solithal  — 20  %, micro- lithal  — 8  %, psam-mal  — up to 3  %, CPOM (deposits of coarse particulate organic matter, e. g. fallen leaves)  — 12  %. An assessment by hy- drobiological parameters us- ing the Methodology of the fi eld protocol) (Afana-syev, 2002), showed that the wa- ter quality in the river corre- sponds to the category “very clean” and “high biological status” in all seasons. Th e value of ТВІ and ВВІ indexes is 10 points. Saprobic index of Pantle&Buck calculated by macrozoobenthos is 1.2–1.5, which corresponds to α-oligosaprobic zone. Found at this location 4 specimens (one female) had a length from 6.3 to 8.2 cm and were quite regularly distributed along the location, preferring the habitats with the depths of 0.25–0.3 m and the slowest fl ow. One more crayfi sh of the size 4.2 cm was found in the mouth of the tributary. Further downstream the Neretvica till the confl uence with the Crny Potok (fi g. 1, area 1), a few crayfi sh were found in the main river course and at the mouths of the tribu- taries of Obascica and Mala Neretvica using electrofi shing. In total, 5 crayfi sh were found. At the confl uence of the Crny Potok and Neretvica, a signifi cant concentration of the crayfi sh was found (coordinates 43°49´33.9˝ N 17°51´20.8˝ E) (fi g. 1, point 2; fi g. 4). Th e average elevation is 699 m a. s. l. It is located 13.5 km downstream the source, in the mouth of the Crny Potok. Th e form of the valley is a U-shaped. Th e riverbed type is classifi ed as a single channel type. Th is site is located in the narrowed part of the Crny Potok canyon. Th ere is a bluff / vertical waterfall with a height of 4–5 m in spring and 2–3 m in autumn. Under the waterfall, there is a deepening with a depth of up to 4 m (in spring) and 2 m (in autumn) (fi gs 4, 5). Fig. 2. General view of the confl uence of the Prolaz tributary into the Neretvica. Fig. 3. Isobath map (depth, m) and isopach map (velocity, m/s) (the locations of the crayfi sh catches are marked with red dots). 289New Findings of White Clawed Crayfi sh, Austropotamobius pallipes (Decapoda, Astacidae)… In the deepening under the waterfall in the Crni Po- tok, only 3 specimens were found; their size was 5, 8 and 6 cm. Directly in Neretvica River, the biggest concentra- tion of the crayfi sh was found at the confl uency with the Crny Potok. Distribution of bottom habitats at the loca- tions of the crayfi sh catches was as follows: HS (hygro- petric sites (water layer on solid su bstrates)  — 10  %, megalithal  — 35  %, macro- lithal  — 20  %, mesolithal  — 10  %, microlithal  — 5  %, psammal  — up to 5  %, CPOM (deposits of coarse particulate organic matter, e. g. fallen leaves) — 15 %. Th e assessment by hydrobiological parameters showed that the water qual- ity in the river corresponds to the category “very clean” and high biological status during all seasons. Th e value of ТВІ and ВВІ indexes is 10 points. Saprobic index of Pantle & Buck calculated by macrozoobenthos is 1.4–1.62, which corresponds to α-oligosaprobic and β-mesosaprobic zones. According to the results of the scuba diving here, more than 20 specimens lived there. In general, the crayfi sh were concentrated at the edges of the hope and behind the rock in the habitats with the slow fl ow and a large amount of plant detritus. Besides, some speci- mens sit at vertical surfaces of boulders and rocks, covered by the moss Fontinalis, as well as hiding behind boulders directly downstream the confl uence. Having place bites made of chicken meat placed for 12 hours, 11 specimens were caught (fi g. 6). Th e smallest one was 7 cm in length and the biggest one — 8.3 cm. Th e sex ratio was 0.83 with male domination. At a distance of more than 50 m upstream and downstream of the confl uence, the crayfi sh were found neither visually nor in traps. Further for 5 km, the crayfi sh were found very rarely in the Neretvica River course. Th e location with the highest concentration of the crayfi sh was found in the mouth of the right tributary of Neretvica–Gorovnik (coordinates 43°47´18.7˝ N 17°49΄24.9˝ E), where they were found along the whole course (150 m) (fi g. 1, point 1; fi g. 7). Th e average Fig. 4. Habitat with the highest concentration of the crayfi sh in Neretvica at the confl uence with the Crni Potok. Fig. 5. Isobath map (depth, m) and isotach map (velocity, m/s) (the locations of the crayfi sh catches using scuba diving are marked with red dots). 290 S. Afanasyev, O. Lietytska, O. Golub, O. Iarochevitch, K. Mudra, O. Marushevska elevation is 416 m a. s. l. It is located 50 m upstream from the confl uence with the Neretvica River. Th e form of the valley is U-shaped. Th e riverbed type is classifi ed as a single channel type. Maps of depths are created for the site of 30 m length. Flow types are broken stand- ing waves, unbroken standing waves, and rippled. Th e average width was 2 m and varied from 1.5 to 7 m (fi g. 8). Bed elements included bars and step/pools. Th e average depth was 0.15 m, with a maximum of 0.3 m. Th e average velocity was 0.2 m/s, with a maximum of 0.4 m/s (fi g. 8). Th e distribution of bottom habitats in the location with the highest crayfi sh concentrations are as follows: megalithal — 5 %, macrolithal — 30 %, mesolithal — 20 %, microlithal — 10 %, psammal — 10 %, CPOM — 20 %. Th e assessment by hydrobiological parameters using Methodology of the Field proto- col showed that the water quality in the river corresponds to the category “very clean” and high biological status during all seasons. Th e value of ТВІ and ВВІ indexes is 10 points. Sap- robic index of Pantle & Buck calculated by macrozoobenthos is 1.3–1.5, which corresponds to α-oligosaprobic zone. Th e number of the crayfi sh in the habitats with slow fl ow 0.11–0.2 m/s with cobble and gravel deposits and many roots and plant detritus can reach 2–3 items per m2. Th e sizes of the specimen varied from 4.3 to 8 cm. Sex ratio was 0.83 with male dominance. Further in the main riverbed and upstream the confl uence with tributary Gorovnik only a few specimens were found using electrofi shing. Th e crayfi sh habitat at the lowest elevation (268 m a. s. l.) was found in Neretvica (fi g. 9). 19 km downstream its source. Th e form of the valley is U-shape. Th e riverbed type is classifi ed as a single channel type. Fig. 6. Extraction of the crayfi sh from the trap at Neretvica near the confl uence with the Crny Potok. Fig. 7. Typical crayfi sh habitats in the Gorovnik. 291New Findings of White Clawed Crayfi sh, Austropotamobius pallipes (Decapoda, Astacidae)… Maps of depths are created for the site of 50 m length. Flow types are turbulent, broken standing waves, unbroken standing waves, and rippled. Th e average width was 8 m and var- ied from 5.5 to 12 m. Bed elements included bars, rocks, and step/pools. Th e average depth was 0.35 m, with a maximum of 0.6 m. Th e average velocity was 0.4 m/s, with a maximum of 1.2 m/s (fi gs 10). Distribution of bottom habitats at the locations with the crayfi sh are as follows: megalital  — 5  %, macrolithal  — 30  %, mesolithal  — 25  %, microlithal  — 15  %, psam- mal — 15 %, CPOM — 10 %. Assessment by hydrobiological parameters showed that the presence of Lyngbya and Oscillatoria, as well as the increase of the number of Oligochae- Fig. 8. Isobath map (depth, m) and isotach map (velocity, m/s) — autumn 2017. Fig. 9. Lowest habitat of the crayfi sh in the Neretvica. 292 S. Afanasyev, O. Lietytska, O. Golub, O. Iarochevitch, K. Mudra, O. Marushevska ta, signals the organic pollution of the river because of the fi sh farm located upstream. Saprobic index of Pantle & Buck calculated by macrozoobenthos is 1.6–1.8, which corre- sponds to β-mesosaprobic zone. Values of ТВІ and ВВІ correspond to 7–9 scores, which correspond to water quality “very clean” in spring and “clean” in autumn and 1–2 classes of eco status. All observed specimens were found behind boulders at depths 0.2–0.3 m and velocity 0.2–0.8 m/s. Out of 6 caught species of the size varying from 6.2 to 7.5 cm, only two were females. Th e size structure of the crayfi sh populations at diff erent localities is presented in fi gu- re 11. Th e most balanced structure of the population, represented by the juvenile as well as adult species is in the Gorovnik. Discussion of the results In the territory of Bosnia and Herzegovina, A. pallipes is present mainly in the Neretva basin, partly in the Una and Tsetina River basins (Trožić-Borovac et al., 2012). Th is spe- cies was registered at elevations from 180 to 1024 m a. s. l., but most habitats are located at elevations from 300 to 600 m a. s. l. Water temperature, measured during surveys var- ied from +7 to +20 °С. Saprobic index defi ned by the composition of macroinvertebrates and phytobenthos shows that the crayfi sh is present in clean and slightly polluted waters Fig. 10. Isobath maps (depth, m), isotach map (velocity, m/s) — autumn. Fig. 11. Size structure of cray fi sh by locations. 293New Findings of White Clawed Crayfi sh, Austropotamobius pallipes (Decapoda, Astacidae)… (Trožić-Borovac et al., 2012). Based on indirect data, one can state that more than 2/3 of the crayfi sh population in the Neretva basin is concentrated in the Neretvica basin. According to our data, the maximum elevation where the crayfi sh were found in the Neretvica River basin was 918 m a. s. l., located 8 km downstream its source, minimal — 268 m a. s. l., located 19 km downstream the source. Temperature diapason was from +5 to +12.4 °С. Depth diapason was from 0.1 to 1 m (mostly till 0.4 m). Diapason of velocities was from 0 to 0.6 m/s (mainly 0.2–0.3 m/s). Saprobic index of Pantle & Buck calculated by macrozoobenthos in the locations with crayfi sh concentrations was 1.2–1.8. Our studies showed that the crayfi sh are very irregularly distributed in the Neretvica basin. Th e crayfi sh are almost absent at well-fl ushed habitats without CPOM (deposits of coarse particulate organic matter, e. g., fallen leaves), as well as at habitats with monotonous boulders or gravel-sand bottom. Signifi cant heterogeneity of bottom habitats as a precon- dition for the high concentration of the crayfi sh is mentioned in the study of (Demers et al., 2003). In the Neretvica River, the obligatory condition of mass concentrations of crayfi sh is the presence of CPOM at the level of not less than 10 % from the total area of substrates as well as the presence of at least 6 types of bottom habitats. In the Neretvica River, such conditions were present at confl uences with tributaries as well as at their mouths. Th e study of the size structure of the crayfi sh population showed the presence of juve- nile crayfi sh with a size of less than 5 cm in the Neretvica River course. Th e most balanced structure of the crayfi sh population represented by juvenile as well as adult species is ob- served in Gorovnik (fi g. 11). Many authors state about the competition inside of one spe- cies population of many crayfi sh species, leading to the fact that adult species will remove juvenile ones (Stain, 1977; Lodge and Hill, 1994). Th e main reasons for this include canni- balism and competition for habitats, stimulating juvenile crayfi sh to occupy free from adult habitats (Momot, 1993; Lodge and Hill, 1994). But if this hypothesis is correct then small crayfi sh should be met in more diverse habitats than adults who occupy the most “comfort- able” habitats. Th is tendency was not observed in the Neretvica basin. Moreover, quite long stretches of the river were not inhabited by the crayfi sh (neither adult, not juvenile ones). Th is confi rms the presence of additional factors, aff ecting the distribution of the crayfi sh. In our study, such a factor can be the presence of predator fi sh. In the Neretvica basin dur- ing the ichthyological surveys 3 trout species were found, in stomachs of which remains of A. рallipes were found. Without discussion of the peculiarities of the quantitative distribu- tion of the fi sh, one can note that in the places of the crayfi sh concentrations, electrofi sh- ing showed lower density of the fi sh compared with other locations. Besides, in the upper reaches of the Neretvica, as well as in its mouth where the crayfi sh was not observed, the fi sh abundance was much higher than in the rest of the riverbed and tributaries (except the upper reaches of the Chrny Potok, where there were very high trout concentrations and crayfi sh were absent). Observation of the impact of predators on the survival of the crayfi sh envisages that the juvenile crayfi sh, which is very vulnerable for predator fi sh, will prefer the shallow waters or the habitats with CPOM concentrations at the bottom, where they can hide (Englund, 1999; Englund and Krupa, 2000). Adult crayfi sh are less vulnerable to the fi sh and can occupy deeper waters to avoid land predators such as otter and mink. Such a spatial distribution of the crayfi sh was fi xed in the Neretvica basin. Th e small up to 5 cm crayfi sh were found in shallow waters, where the trout enters during spawning only. According to our research clawed crayfi sh were found at elevations from 268 m to 918 m a. s. l. in the Neretvica basin. Th e sex distribution varied from 0.33 to 0.83 in favour of males. Th e crayfi sh were irregularly distributed and this can be explained by the charac- ter of bottom h abitats as well as pressure from predators. Th e biggest concentration of the crayfi sh was fi xed in the habitats with slow fl ow and presented of the debris and plant detri- tus, where small crayfi sh can hide from predators. Mass concentrations of the crayfi sh were fi xed in the mouths of tributaries wherein highly heterogeneous habitats juvenile crayfi sh can hide in shallow waters. Th e obligatory precondition for the population reproduction 294 S. Afanasyev, O. Lietytska, O. Golub, O. Iarochevitch, K. Mudra, O. Marushevska is the presence of habitats with a high amount of СРОМ at the bottom. Th is fact should be taken into account during hydropower construction when downstream of the dike because of the phenomenon of sedimentation hunger and absence of the small fraction juvenile crayfi sh could lose an opportunity to hide. References Afanasyev, S. A. 2002. Development of European Approaches to Biological Assessment of the State of Hydro- ecosystems and Th eir Application to the Monitoring of Ukrainian Rivers. 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