Anali za istrske in mediteranske študijeAnnali di Studi istriani e mediterranei Annals for Istrian and Mediterranean Studies 

UDK 5                       Annales, Ser. hist. nat., 29, 2019, 2, pp. 159-280, Koper 2019 ISSN1408-533X 
UDK 5 ISSN 1408-533X (Print) ISSN 2591-1783 (Online) 

Anali za istrske in mediteranske študije Annali di Studi istriani e mediterranei Annals for Istrian and Mediterranean Studies 
Series Historia Naturalis, 29, 2019, 2 
KOPER 2019 
Anali za istrske in mediteranske študije - Annali di Studi istriani e mediterranei - Annals for Istrian and Mediterranean Studies 
ISSN 1408-533X (Tiskana izd.)    UDK 5 Letnik 29, leto 2019, številka 2 ISSN 2591-1783 (Spletna izd.) 
Alessandro Acquavita (IT), Nicola Bettoso (IT), Christian Capapé UREDNIŠKI ODBOR/ (FR), Darko Darovec, Dušan Devetak, Jakov Dulčić (HR), Serena COMITATO DI REDAZIONE/ Fonda Umani (IT), Andrej Gogala, Daniel Golani (IL), Danijel 
BOARD OF EDITORS: Ivajnšič, Mitja Kaligarič, Marcelo Kovačič (HR), Andrej Kranjc, Lovrenc Lipej, Vesna Mačić (ME), Alenka Malej, Patricija Mozetič, Martina Orlando-Bonaca, Michael Stachowitsch (AT), Tom Turk, Al Vrezec 
Glavni urednik/Redattore capo/ Editor in chief: Darko Darovec 
Odgovorni urednik naravoslovja/ 

Redattore responsabile per le scienze naturali/Natural Science Editor: Lovrenc Lipej 
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Anali za istrske in mediteranske študije - Annali di Studi istriani e mediterranei - Annals for Istrian and Mediterranean Studies 
UDK 5                                                      Letnik 29, Koper 2019, številka 2                                      ISSN 1408-533X (Print) ISSN 2591-1783 (Online) 


VSEBINA / INDICE GENERALE / CONTENTS 2019(2) 
50 LET MORSKE BIOLOŠKE POSTAJE  
NACIONALNEGA INŠTITUTA ZA BIOLOGIJO  
I 50 ANNI DELLA STAZIONE DI BIOLOGIA  
MARINA DELL'ISTITUTO NAZIONALE  
DI BIOLOGIA  
50 YEARS OF THE MARINE BIOLOGY STATION  
OF THE NATIONAL INSTITUTE OF BIOLOGY  
Lovrenc LIPEJ, Domen TRKOV, Domen STANIČ,  
Sara CERNICH & Saul CIRIACO  
First Record of Sergeant Major, Abudefduf  
saxatilis (Linnaeus, 1758) in the Adriatic Sea .........  159  
Prvi zapis o pojavljanju velikega seržanta,  
Abudefduf saxatilis (Linnaeus, 1758)  
v Jadranskem morju  
Valentina PITACCO & Selahattin Ünsal KARHAN  
First Record of Flabelliderma cinari Karhan,  
Simboura & Salazar-Vallejo, 2012 (Polychaeta:  
Flabelligeridae) from the Adriatic Sea ...................  167  
Prvi zapis o pojavljanju vrste Flabelliderma  
cinari Karhan, Simboura & Salazar-Vallejo, 2012  
(Polychaeta: Flabelligeridae) v Jadranskem morju  
Ana FORTIČ, Domen TRKOV, Borut MAVRIČ  
& Lovrenc LIPEJ  
Assessment of Bryozoan Xenodiversity  
in the Slovenian Coastal Sea .................................  173  
Ocena ksenodiverzitete mahovnjakov  
v slovenskem obalnem morju  
Martina ORLANDO-BONACA, Janja FRANCÉ,  
Borut MAVRIČ & Lovrenc LIPEJ  
Impact of the Port of Koper on  
Cymodocea nodosa Meadow ...............................  187  
Vpliv koprskega pristanišča na travnik  
kolenčaste cimodoceje (Cymodocea nodosa)  

IHTIOLOGIJA ITTIOLOGIA ICHTHYOLOGY  
Akraam Faraj KARA, Mohamed AL HAJAJI, Hisham GHMATI & Esmail A. SHAKMAN Food and Feeding Habits of Mustelus mustelus (Linnaeus, 1758) (Chondrichthyes: Triakidae) Along the Western Coast of Libya ......................... Prehranjevalne navade navadnega morskega psa, Mustelus mustelus (Linnaeus, 1758) (Chondrichthyes: Triakidae), vzdolž zahodne obale Libije Youssouph DIATTA, Almamy DIABY, Sihem RAFRAFI-NOUIRA & Christian CAPAPÉ Capture of a Rare Endangered Species Leafscale Gulper Shark Centrophorus squamosus (Chondrichthyes: Squalidae) from the Coast of Senegal (Eastern Tropical Atlantic) .................... Ulov redkega in ogroženega morskega psa Centrophorus squamosus (Chondrichthyes: Squalidae) iz obalnih voda Senegala (vzhodni tropski Atlantik) Sihem RAFRAFI-NOUIRA, Christian REYNAUD & Christian CAPAPÉ Morphological Deformities in a Striped Sea Bream Lithognathus mormyrus (Osteichthyes: Sparidae) from Northern Tunisian Waters (Central Mediterranean Sea) ................................. Morfološke deformacije pri ovčici Lithognathus mormyrus (Osteichthyes: Sparidae) iz severno tunizijskih vod (osrednje Sredozemsko morje)  197 205 211  

Sihem RAFRAFI-NOUIRA, Christian REYNAUD &  
Christian CAPAPÉ  
On a Occurrence of Gadella maraldi  
(Osteichthyes: Gadiformes: Moridae) on the  
Tunisian Coast (Central Mediterranean Sea) ..........  219  
O pojavljanju vrste Gadella maraldi  
(Osteichthyes: Gadiformes: Moridae) ob  
tunizijski obali (osrednje Sredozemsko morje)  
Mohamed Mourad BEN AMOR, Marouene  
BDIOUI, Khadija OUNIFI-BEN AMOR, Christian  
REYNAUD & Christian CAPAPÉ  
Unusual Record of Round Fantail Stingray  
Taeniurops grabata (Chondrichthyes:  
Dasyatidae) from the Tunisian Coast  
(Central Mediterranean Sea) .................................  223  
Nenavadni zapis o pojavljanju morskega biča  
vrste Taeniurops grabata (Chondrichthyes:  
Dasyatidae) iz tunizijskih voda (osrednje  
Sredozemsko morje)  
JADRANSKA MORSKA FAVNA  
FAUNA MARINA ADRIATICA  
ADRIATIC MARINE FAUNA  
Roland R. MELZER, Martin HEß, Manuel A.  
STAGGL, Tihomir MAKOVEC & Borut MAVRIČ  
Hippolyte prideauxiana Leach, 1817: First  
Record for the Northern Adriatic and  
Observations on Mimetic Colouration ..................  231  
Hippolyte prideauxiana Leach, 1817: prvi  
zapis o pojavljanju v severnem Jadranu  
s podatki o barvnemu prikrivanju  
Mona REZAEI, Al VREZEC, Borut MAVRIČ  
& Lovrenc LIPEJ  
Biometry and Population Gender Structure  
of Three Crab Species (Crustacea:  
Decapoda) from Sandy Bottom  
in the Northern Adriatic Sea .................................  235  
Biometrija in spolna struktura pri treh vrstah  
rakovic (Crustacea: Decapoda) iz sedimentnega  
dna severnega Jadrana  

ONESNAŽEVANJE OKOLJA 
INQUINAMENTO DELL’AMBIENTE ENVIRONMENTAL POLLUTION 
Sezginer TUNÇER, Sedat GÜNDOGDU, Cem ÇEVIK & Aytug ZILIFLI 
Belone belone (Linnaeus, 1760) and Spicara smaris (Linnaeus, 1758) Entangled in Plastic Collars in the Dardanelles Strait, Turkey ............... 247 Iglica, Belone belone (Linnaeus, 1760), in girica, Spicara smaris (Linnaeus, 1758), zapleteni v plastični ovoj v ožini Dardanele, Turčija 

Jamila FLIOU, Ali AMECHROUQ, Mohammed ELHOURRI, Ouassima RIFFI & Mostafa EL IDRISSI 
Determination of Heavy Metal Content in a Daphne gnidium L. Plant Using Atomic Absorption Spectroscopy ...................................... 253 
Določevanje vsebnosti težkih kovin v volčinu vrste Daphne gnidium L. z uporabo atomske absorbcijske spektroskopije 
DELO NAŠIH ZAVODOV IN DRUŠTEV 
ATTIVITA DEI NOSTRI ISTITUTI E SOCIETA ACTIVITIES BY OUR INSTITUTIONS AND ASSOCIATIONS 


Simon KERMA 
Half a Century of the Marine Biology Station Piran ............................................ 261 
Pol stoletja delovanja Morske biološke postaje Piran 
Navodila avtorjem ................................................ 267 Istruzioni per gli autori .......................................... 269 Instruction to Authors ............................................ 271 
Kazalo k slikam na ovitku ..................................... 273 Index to images on the cover ................................ 273 

received: 2019-09-03 DOI 10.19233/ASHN.2019.25 

BIOMETRY AND POPULATION GENDER STRUCTURE OF THREE CRAB SPECIES (CRUSTACEA: DECAPODA) FROM SANDY BOTTOM IN THE NORTHERN ADRIATIC SEA 
Mona REZAEI 
Faculty of Natural sciences and Mathematics, University of Maribor, Koroška cesta 160, SI-2000 Maribor, Slovenia e-mail: mona13831383@yahoo.com 
Al VREZEC 
Department for Organisms and Ecosystems Research, National Institute of Biology, Večna pot 111, SI-1000, Ljubljana, Slovenia 
Borut MAVRIČ & Lovrenc LIPEJ 
Marine Biology Station, National Institute of Biology, Fornače 41, Piran, Slovenia 
ABSTRACT 
The aim of the study was to investigate the distribution and population structure of three species of crabs (De-capoda: Crustacea), Medorippe lanata, Liocarcinus depurator and Liocarcinus vernalis for their biometric relation­ships. A total of 1100 specimens of three species were caught from waters off the northern Adriatic Sea in December 2013. Biometric relationships and condition factor (Fulton’s coefficient index) were measured for all the studied species. Size dimorphism was also observed in M. lanata with females showing significantly larger carapace size than males without significant difference in wet weight. The studied species did not differ significantly in the results of the condition index. 
Key words: Medorippe lanata, Liocarcinus depurator, Liocarcinus vernalis, biometry, condition factor, Adriatic Sea 
BIOMETRIA E STRUTTURA DI GENERE NELLE POPOLAZIONI DI TRE SPECIE DI GRANCHI (CRUSTACEA: DECAPODA) DI FONDI SEDIMENTARI DELL’ADRIATICO SETTENTRIONALE 
SINTESI 
Lo scopo dello studio era quello di verificare la distribuzione e la struttura della popolazione di tre specie di granchi (Decapoda: Crustacea), Medorippe lanata, Liocarcinus depurator e Liocarcinus vernalis, per evidenziare le relazioni biometriche. Un totale di 1100 esemplari appartenenti alle tre specie sono stati catturati nelle acque al largo della costa dell’Adriatico settentrionale, nel dicembre 2013. Le relazioni biometriche e il fattore di condizione (indice del coefficiente di Fulton) sono stati calcolati per tutte le specie studiate. Il dimorfismo dimensionale e stato osservato anche in M. lanata, dove le femmine hanno dimensioni del carapace significativamente maggiori rispetto ai maschi, senza differenza significativa nel peso umido. Le specie studiate non differivano significativamente nei risultati dell’indice di condizione. 
Parole chiave: Medorippe lanata, Liocarcinus depurator, Liocarcinus vernalis, biometria, fattore di condizione, mare Adriatico 
235 
INTRODUCTION 
Measurement and analysis of biometric parameters could assist in understanding the biological and physi­ological status of crustaceans. One such importance has been previously shown for fecundity of Potamon koolooense (Rawat et al., 2016). The morphometric and allometric analyses or relation amongst different body segments is functionally significant in biology (Huber, 1985). Investigation of length-weight relationship is widely performed and used to study different aspects of animal and aquatic population such as maturity and health (Patil & Patil, 2012). In this context, the condition factor is used to study and compare the ecological and health characteristics of any species. Condition index differs from growth in that it shows weight for a given length and it is hypothesised that improved condition is achieved through increased weight at a given length (Bolger & Connolly, 1989). 
Sex ratio is an assessment of animals and aquatic population condition which has been defined as an indicator of population behaviour and fecundity (Pan-tulu, 1961). Sex ratio gives important information on separation or disappearance of either sexes in any given ecosystem. This information may be used to investigate possible influence of the environment or human activity on the sex imbalance in the population (if any). However, the imbalance in sex ratio may be simply attributed to the natural behaviour of the population such as seasonal migration of females for spawning (Carlino et al., 2014). 

Crustaceans are the most numerous groups of inver­tebrates in marine ecosystem, with many species facing population decline (Bellido et al., 2011). Our study focuses on brachyuran decapods (Crustacea: Decapoda: Brachyura) since many crab species are endangered by environmental and human factors such as by-catch, where many non-target animals are also killed, caus­ing a decline in crab populations (Bellido et al., 2011). However, many other factors can cause species declines, which are poorly studied in marine crabs. 
The aim of the paper is to explore biometry of three crab species populations in the northern Adriatic Sea, namely the species Liocarcinus depurator (Linnaeus, 1758), Liocarcinus vernalis (Risso, 1816) and Medorippe lanata (Linnaeus, 1767), which are all characteristic for sandy soft bottoms (Manning et al., 1981; Abelló et al., 1991). Although these crabs are frequently caught in fishermen nets as bycatch (Ingle, 1997; Bergmann & Moore, 2001), they are relatively poorly studied. Infor­mation provided by this study will give valuable insight into their ecology and could facilitate future sustainable management of these species in the Adriatic Sea. 
MATERIAL AND METHODS 
Study area 
The 67 sampling stations were distributed over the area shown in Figure 1. Stations occurred at different depths (0–30 m: 39 stations; 30–50 m: 17 stations; 50– 100 m: 11 stations). Crabs of the three studied species were obtained as a by-catch of fishery nets. Sampling took place in the waters off the northern Adriatic Sea in December 2013 as a part of fishery expedition. 
Studied species 
Liocarcinus depurator is distributed in bottoms of the North Sea, Atlantic Ocean, Mediterranean Sea, and also in the Black Sea (Ateş, 1999). It grows up to 50 mm in width and 40 mm in length (Hill, 2007) and can be dis­tinguished from other crabs by the curved rows of white spots on its carapace (Telnes, 2012). It is a predominant brachyuran in the by-catch in Mediterranean demersal fisheries, as deep as 200 m (Sarda & Palomera, 1981). 
L. depurator constitutes a main fraction of the cast-off species in many marine fisheries (Bergmann & Moore, 2001). Crabs often inhabit harbours with the proximity to anchored fishing vessels and feed on trash thrown off the board. 
The grey swimming crab Liocarcinus vernalis is a crab inhabiting shallow waters. It is present in the Mediterranean Sea and from West Africa to the southern North Sea (McCarthy et al., 2005). 
The distribution of benthic crab Medorippe lanata extends from Atlantic Ocean to the Mediterranean (Man­


Fig. 2: The image of two studied crab species: (a) Liocarcinus depurator (Risso, 1816) and (b) Medorippe lanata (Linnaeus, 1767). Sl. 2: Raziskane vrste rakovic: (a) Liocarcinus depurator (Risso, 1816) in (b) Medorippe lanata (Linnaeus, 1767). 
ning et al., 1981) in depths from 9 to 952 m of muddy bottoms (D’Udekem d’Acoz, 1999). Carapace length in females and males has been reported to range from 10­29 and 9-29 mm respectively (Rossetti et al., 2006). This crab is subjected to trawling and eventually discarded due to the lack of commercial value (Biagi et al., 2002). Occasionally it is caught in significant numbers in trawls of fishing vessels and in squid or crab/lobster pots (Ingle, 1997). 
Biometric measurements 
Crab specimens were measured by Vernier calliper with accuracy up to 0.01 mm. The biometric parameters which were measured are the carapace length and width. All crabs were sexed and their wet weight was measured by using digital balance (Palmscale 8; 300g x 0.01 Capacity) (Lara et al., 2013). Due to the damage occurred during sampling, gender could not be identi­fied in four crab specimens, all of L. vernalis. These crabs were excluded from analysis where males and females were compared. 
Data analysis 
Analysis of data was performed using SigmaPlot 13 for Windows (Systat Software Inc. CA, USA). Normal distribution of data was confirmed by the Kolmogorov– Smirnov test. The mean values of two groups (e.g. female and male) of normally distributed data were compared by a Student’s t test. The median values of two groups of data that were not normally distributed were compared using the non-parametric Mann–Whitney U test. Moreo­ver, non-normally distributed data were subjected to Kruskal–Wallis test by ranks followed by the Wilcoxon rank-sum test. Chi-square test was performed to com­pare the rates. A P-value of 0.05 or less was considered as significant. 
In addition, regression analysis was performed to investigate the relationship between carapace weight and length. To compare condition among species in question, Fulton’s condition factor (Fulton, 1904) was calculated as: K=100W/CL3 where W was weight (g) and CL carapace length (cm). 
RESULTS 
Overall survey of the studied populations 
All specimens of crabs were collected from 32 sam­pling stations. The number per station varied from 1 to 92 specimens. Out of 922 crabs, 451 individuals were 
L.vernalis, 317 L. depurator and 154 M. lanata (Tab. 1). 
Except for M. lanata, the number of males in other species was higher than that of females (Tab. 2). The sex ratio in all species (except for M. lanata) was found to be significantly different from 1:1 (chi-square test). 
Tab. 1: The number of analysed males (M) and females 
(F) per crab species. Tab. 1: Število analiziranih samcev (M) in samic (F) raziskanih vrst rakovic. 
Species  Sex  Number of individuals  
Liocarcinus depurator  M >  192  
F +  125  
Liocarcinus vernalis  M >  301  
F +  150  
Medorippe lanata  M >  68  
F +  86  


Tab. 2: Sex ratio in population of examined three crab species. Significant difference from 1:1 ratio was indicated by chi-squared test. Legend: 1 - Regardless of gender in the whole population, 2 - P-values indicate significant difference from hypothetical ratio of 1:1. Tab. 2: Delež samic in samcev pri treh raziskanih vrstah rakovic. Signifikantni odklon od razmerja 1:1 smo pre­verjali s Hi- kvadrat testom. Legenda: 1 - Delež vrste ne glede na spol, 2 – P-vrednost kaže signifikantni odklon od hipotetičnega razmerja med spoloma 1:1. 
Ratios in the population  Chi-square test  
Species  N Females  N Males  Proportion of population1  % Females  % Males  .2  P-Value2  
L. depurator  125  192  34.4  0.39  0.61  6.75  0.009  
L. vernalis  150  301  48.9  0.33  0.67  25.35  <0.001  
M. lanata  86  68  16.7  0.56  0.44  1.35  0.25  

No effect of depth was found on the distribution of the studied crabs. 
Wet weight 
Wet weight was compared among the three studied species (Fig. 3). Non-parametric analysis revealed sig­nificantly higher wet weight in males than in females of 
L. vernalis (Mann–Whitney U test: U=18377, P=0.012). The males of L. vernalis were also significantly larger than males of L. depurator and M. lanata. The difference among females across species was not significant (Wil­coxon rank-sum test: P=0.63). 
Carapace width-carapace length relationships 
Liocarcinus depurator 
Carapace length was on average larger than carapace width in L. depurator. Carapace width ranged from 13.7 to 29.0 mm in males and 14.7 to 27.2 mm in females. Carapace length ranged from 11.2 to 42.3 mm in males and 17.9 to 39.4 mm in females. No statistically significant differences were found between females and males of L. depurator in carapace width and length. There was a significant correlation between carapace width and length for males and females com­bined (Fig. 4). 
Liocarcinus vernalis 
Carapace length was on average larger than cara­pace width. The latter ranged from 10.5 to 26.5 mm in males and 14.7 to 27.2 mm in females. Carapace length ranged from 14.8 to 43.1 mm in males and 14.0 to 37.3 mm in females. No statistically significant differences were found between females and males of L. vernalis in carapace width and length. There was significant cor­relation between carapace width and length for males and females combined (Fig. 5). 

Wet weight (g) 
14,0 12,0 10,0 8,0 6,0 4,0 2,0 0,0 
* 
*  *  

Female Male 
L.depurator 
L.vernalis 
M.lanata 
Fig. 3: Comparison of wet weight among different species and between genders within species. Asterisk indicates a statistical difference (* P<0.05). Sl. 3: Primerjava mokre teže pri različnih vrstah in spolih. Zvezdica označuje statistično razliko (* P<0.05). 
Fig. 4: Scatterplot and relationship between carapace width and length in Liocarcinus depurator (t=69.2; P<0.001). Sl. 4: Razpršeni diagram in odnos med širino in dolžino karapaksa pri vrsti Liocarcinus depurator (t=69.2; P<0.001). 

Medorippe lanata 
Carapace length was on average larger than cara­pace width. Carapace width ranged from 7.0 to 17.35 mm in males and 7.8 to 17.3 mm in females. Carapace length ranged from 10.0 to 35.5 mm in males and 12.7 to 37.8 mm in females. Carapace width, length and height in females of M. lanata were significantly greater than those of males (Mann–Whitney U test: U=2126, 
width
P=0.01, U2107, P=0.008, U=1967, 
widthlength=lengthheight
P=<0.001) (Fig. 6). 
height
There was significant correlation between carapace width and length for males and females combined (Fig. 7). 
Fulton’s condition index 
The differences between males and females in condi­tion index were not statistically significant (Mann-Whitney U test) within and between any of the species (Tab. 3). 


Fig. 6: Carapace width (a), length (b) and height (c) of females (n=86) and males (n=68) of M. lanata. Asterisk indicates a statistical difference (* P<0.05; ** P<0.01). Values (in mm) represent means ± standard error (SE). Sl. 6: Širina (a), dolžina (b) in višina (c) karapaksa pri samicah (n=86) in samcih (n=68) vrste M. lanata. Zvezdica označuje  statistično razliko (* P<0.05; ** P<0.01). Vrednosti (v mm) predstavljajo povprečje in standardni odklon (SE). 

DISCUSSION 
Crab populations 
L. vernalis and L. depurator were caught in higher numbers, which could be a possible indication of their dominance in the ecosystem of the northern Adriatic Sea. These two species represent 70% of all collected individuals. L. vernalis has also been shown previously to be one of the dominant species in Spanish Bay of Cadiz (Drake et al., 1998). One reason for dominance could be the environmental conditions such as depth. It has been shown that L. depurator density is highest at depths between 51–100 m in Iberian Peninsula (Rufino et al., 2005). However, in this study L. depurator and L. vernalis distribution was not affected by depth. Other factor affect­ing population could be the impact of predators which could not be controlled and measured in this study. 
The maximum density of L. depurator was reported to occur in depths below 100 m (Rufino et al., 2005) corre­sponding to this study’s range of depths. The distribution of L. vernalis has been reported to occur in regions as deep as 130 m in the Mediterranean Sea (Koch & Ďuriš, 2016) and the maximum recruitment of M. lanata has been found within 20-100 m depth (Abelló et al., 1988) which corresponds to the depth range in this study. 
Higher ratio of males to females is evident in both studied Liocarcinus species. This is in agreement with Sartor et al. (2006) who reported higher vulnerability of males to fishing and sorting operations compared with females. One alternative explanation to the higher ratio of males to females may be the migration of females to other regions for spawning during the sampling period as shown previously for Atlantic blue crab Callinectes sapidus (Carlino et al., 2014). 
Biometry 
Males of L. vernalis were significantly larger than fe­males, however this was not associated with significant differences in carapace dimensions between males and females. No other scientific report was found to confirm sexual dimorphism in L. vernalis. The weight of females of M. lanata were found to be larger than that in males numerically, however, the difference was not statisti­cally significant. The sexual dimorphism is observed in M. lanata at carapace level with the dimensions of carapace being significantly larger in females. Sexual dimorphism in size of chelae was reported previously in 
M. lanata (Rossetti et al., 2006). The range of carapace length of L. depurator in this study was close to that reported previously by Ungaro et al. (2000). 
Strong relationship between carapace width and length is observed for all species in females and males. The relationship between carapace width and length is used to indicate health and physiological conditions within the population (Bolger & Connolly, 1989). 
Fulton’s condition index 
The condition factor is used as an indicator of health and biomass which is found to change in response to crabs’ alterations in weight. This may occur under different feeding, growth and physiological conditions (Bolger & Connolly, 1989). Condition index of L. depu­rator in this study is similar to those obtained by Aydin (2018). No significant difference in this parameter between female and male of all studied crabs could 

Tab. 3: Fulton’s condition index of the studied crab species. Values represent means ± standard error (SE). Tab. 3: Fultonov kondicijski indeks pri treh vrstah rakovic. Vrednosti predstavljajo srednjo vrednost in standardni odklon (SE). 
Species  Total  Female  Male  Gender effect  
n (total)  Mean±SE  Mean±SE  Mean±SE  P-value  U-test  
L. depurator  298  50.4±2.5  51.0±3.0  49.8±2.0  0.46  15499  
L. vernalis  442  55.7±2.4  57.6±2.9  53.9±1.9  0.31  27559  
M. lanata  149  55.8±3.8  51.7±3.6  59.9±4.1  0.06  4954  

indicate that there were no environmental, nutritional and physiological effect on body condition between both sexes. 
The information on the biometry and population pro­file of three species of crabs in northern Adriatic Sea can be useful in the future studies to evaluate and monitor any changes in the population of crabs. Further, the obtained data in this study could be helpful when performing research on various crab predators in the shallow area of the northern Adriatic Sea such as sharks and rays. 
The specimens which are killed as bycatch in fisher­ies provide a valuable source of data for studying the ecology of such species. Thus, it is important to obtain as much as possible data regarding these crabs and other organisms due to the collateral damage imposed by fish­eries. Further studies are needed to study how environ­mental and human factors may affect crab populations and their biometrical features in northern Adriatic Sea. One such environmental effect could be the seasonal change in water quality and/or temperature. The knowl­edge in population structure and biometry can be used to adjust regulation leading to protection of crabs and overall benthic fauna in the region. 
ACKNOWLEDGEMENTS 
A special thank goes to all the personnel involved in SoleMon project for assistance in providing samples. 


BIOMETRIJA IN SPOLNA STRUKTURA PRI TREH VRSTAH RAKOVIC (CRUSTACEA: DECAPODA) IZ SEDIMENTNEGA DNA SEVERNEGA JADRANA 
Mona REZAEI 
Faculty of Natural sciences and Mathematics, University of Maribor, Koroška cesta 160, SI-2000 Maribor, Slovenia e-mail: mona13831383@yahoo.com 
Al VREZEC 
Department for Organisms and Ecosystems Research, National Institute of Biology, Večna pot 111, SI-1000, Ljubljana, Slovenia 
Borut MAVRIČ & Lovrenc LIPEJ 
Marine Biology Station, National Institute of Biology, Fornače 41, Piran, Slovenia 
POVZETEK 
Cilj raziskave je bil raziskati razširjenost in populacijsko strukturo treh vrst rakovic (Decapoda: Crustacea), Medorippe lanata, Liocarcinus depurator in Liocarcinus vernalis ter biometrične meritve. V decembru 2013 je bilo v severnem Jadranu ujeto skupno 1100 primerkov, ki so pripadali trem vrstam. Avtorji so opravili biometrične meritve in izračunali Fultonov kondicijski indeks za vse tri vrste. Pri vrsti M. lanata je bila izražena spolna dvoličnost, ki se je kazala v večjih karapaksih samic, čeprav ta ni bila signifikantna v telesni teži. Raziskane vrste se glede kondicijskega indeksa niso statistično razlikovale. 
Ključne besede: Medorippe lanata, Liocarcinus depurator, Liocarcinus vernalis, biometrija, kondicijski indeks, Jadransko morje 
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