Sound production in the Ponto-Caspian goby (Neogobius fluviatilis (Pallas, 1814)) and its acoustic affinity with mediterranean species

Cilj provedenog istraživanja bio je opisati vokalni repertoar ponto-kaspijskog riječnog glavočića (Neogobius fluviatilis) te usporediti njegova akustična svojstva s vokalnim mediteranskim vrstama iz Gobius grupe. Produkcija zvuka bila je inducirana ―testom uljeza. Istražili smo 5 akustičnih svojstva za 13 jedinki. Vokalni repertoar riječnog glavočića sastoji se od niza kratkih zvukova produciranih tijekom agresivnih i reproduktivnih interakcija. Zvukovi se sastoje od rapidno ponovljenih pulseva, tipičnog tonalnog karaktera. Zvukovi traju oko 200 ms uz prosječnu vrijednost frekvencije od oko 80 Hz. Struktura zvuka se nije mijenjala s obzirom na etološki kontekst, što potvrđuje njen stereotipski karakter. Podaci o akustičnim svojstvima riječnog glavočića zajedno sa podacima mediteranskih vrsta, analizirani su pomoću Faktorijalne diskriminantne funkcijske analize (DFA) kako bi procijenili u kojoj se mjeri vrste mogu razlikovati s obzirom na njihova akustična svojstava. Rezultati pokazuju kako je stopa ponavljanja pulseva najvažnije svojstvo za razlikovanje vrsta. Smatramo kako upravo ta karakteristika zvuka sadrži informacije o samoj vrsti zbog čega je ključna pri određivanju filogenetskih odnosa. Naše istraživanje pokazuje, sukladno molekularnim filogenetskim analizama, da se vrste koje produciraju tonalne zvukove grupiraju zajedno. Rezultati provedenog istraživanja interpretirani su sukladno geološkim i filogentskim događajima za koje se vjeruje da su potaknuli specijaciju europskih glavoča.The aim of this study was to describe the vocal repertoire of the Ponto-Caspian goby (Neogobius fluviatilis) and to compare its acoustic properties with those of the other soniferous Mediterranean gobies belonging to the ―Gobius‖ lineage. Sound emission was elicited by means of ―intruder tests‖. 5 acoustic properties were measured from 13 individuals. The vocal repertoire of the species consisted of sequences of short vocalizations (average 200 ms) showing an average fundamental frequency of about 80 Hz during both agonistic and reproductive intraspecific interactions. Sound properties did not differ between reproductive and the aggressive contexts, and the general structure of sounds were highly stereotyped. Discriminant Function Analysis was performed with individual means of five acoustic properties for seven species to assess how well species could be differentiated on the basis of acoustics, and their degree of affinities. The results suggested that the pulse repetition rate of the sounds was the most important property in differentiating the species. The species producing tonal sounds clustered together in line with the results of recent molecular phylogenic studies. The results were discussed in light of the geological and phylogeographic events believed to have driven the diversification of European gobies

Distribution and morphological variations of invasive macrophytes Elodea nuttallii (Planch.) H. St. John and Elodea canadensis Michx in Croatia

The invasive species Elodea nuttallii was recorded for the first time in the Croatian flora in 2006, in the drainage channels of Kopački rit (Baranja). After its establishment, E. nuttallii begins to spread to the eastern and northern part of the drainage channel network from 2006–2009. High water levels are responsible for the linear spreading direction of E. nuttallii, E. nuttallii and E. canadensis show a wide range of morphological variation, which is characteristic of successful invaders. To show morphological variations of two Elodea species, the most impor tant characters indicated in the literature were measured on 24 fresh collected samples from the seven sites in Croatia. In spite of some overlap in leaf length and width between the two Elodea species, the differences of all morphological traits except internode length are statistically significant. In E. nuttallii leaf width, length and internode length show a higher morphological variability as a result of the higher adaptive strategy to environmental parameters. The most reliable morphological characters distinguishing E. nuttallii and E. canadensis are leaf width 0.5 mm below the tip and the angle at the apex. E. nuttallii can be expected to spread to other areas of Croatia

A REVIEW OF EXTANT CROATIAN FRESHWATER FISH AND LAMPREYS Annotated list and distribution

Prvi je put izrađen popis hrvatskih slatkovodnih riba. Temelji se na 1360 povijesnih i novijih literaturnih podataka. Na temelju pregleda literature, u Hrvatskoj je, do danas, zabilježeno 137 vrsta riba iz 30 porodica i 75 rodova. Popis je organiziran sistematski i u njemu se navode podaci o rasprostranjenosti slatkovodne ihtiofaune te jesu li vrste endemične, unesene ili prenesene (translocirane).A checklist of the freshwater fish fauna of Croatia is presented for the first time. It is based on 1360 publications of historical and recent data in the literature. According to the literature review, there were 137 fish species in 30 families and 75 genera recorded in Croatia. The checklist is systematicallyarranged and provides distributional data of the freshwater fish fauna as well as whether the species is endemic, introduced or translocated

THREATENED FISHES OF THE WORLD: Orsinogobius croaticus (Mrakovčić, Kerovec, Mišetić and Schneider, 1996) (Teleostei: Gobiidae)

Orsinogobius croaticus je slatkovodna riba s malom i ograničenom rasprostranjenosti u Jadranskom bazenu u Hrvatskoj i Bosni i Hercegovini gdje nastanjuje hladne krške rijeke i izvore. Glavne prijetnje populacijama su fragmentacija staništa, smanjena kakvoća staništa i unošenje stranih vrsta. Predlažu se preporuke zaštite za poboljšanje učinkovitog očuvanja staništa i proširenje znanja o ovoj vrsti.Orsinogobius croaticus is a freshwater fish with a small and limited distribution range in the Adriatic basin in Croatia and Bosnia-Herzegovina, where it inhabits cold karstic rivers and springs. The main threats to its populations include habitat fragmentation, declining habitat quality and the introduction of alien species. Conservation recommendations are proposed to improve effective habitat preservation and to expand the knowledge about this species

Navike hrvatskih potrošača u online i offline kupovini

kupovina postaje sve prominentnija u svijetu, ali i u Hrvatskoj. Iako se građani Hrvatske prilagođavaju online kupovini, nije istraženo koje proizvode ili usluge preferiraju kupovati online, a koje offline. Cilj rada je istražiti navike hrvatskih potrošača pri online i offline kupovini u korelaciji s vrstom proizvoda ili usluga. Način provođenja istraživanja: Na prigodnom uzorku od 108 ispitanika između 18 i 60+ godina, primijenjen je online upitnik od 64 čestice kojem su, uz demografske podatke, dobivene informacije o preferencijama online i offline kupovine obzirom na: način nabavljanja robe, učestalost nabavljanja robe iz Hrvatskih internet dućana, mišljenje o cijenama proizvoda prilikom kupovine, važnost doticanja i izboru proizvoda, procjenu jednostavnosti vraćanja proizvoda, usporedbe kvalitete usluge, praktičnost i informiranja prilikom kupovine. Ovi podaci su se odnosili na osam kategorija proizvoda ili usluga; hrana i bezalkoholna pića, odjeća i obuća, pokućstvo, zdravlje, komunikacija i aplikacije, rekreacija i kultura, obrazovanje, restorani i hoteli. Rezultati: Prema dobivenim rezultatima utvrđena je statistički značajna korelacija između navika online kupovine i dobi ispitanika te da je kronološka dob značajno povezana s edukacijom, ali i sumnjom u sigurnost online kupovine. Dobiveni rezultati su u suprotnosti s rezultatima istraživanja Lyera i Eastmana (2006) koji su utvrdili da su pismenije i tehnološki svjesnije starije osobe motiviranije koristiti internet trgovine. Sivansan, Monisha et. al., (2017) utvrdili su da žene kupuju više online, nego muškarci te da osobe starije od 35 godina rjeđe kupuju online u usporedbi s mlađim stanovništvom, što našim istraživanjem nije potvrđeno, već dobiveni rezultati sugeriraju da ispitanici pokazuju podjednaku preferenciju online kupovini u odnosu na spol. Zaključak: Hrvatski kupci našeg uzorka iskazuju veću nesigurnost prema online kupovini s porastom kronološke dobi, žene i muškarci podjednako preferiraju online kupovinu ovisno o financijskim mogućnostima. Obzirom da je istraživanje provedeno na relativno malom prigodnom uzorku ispitanika, za generaliziranje rezultata, trebalo bi navike prema online ili offline kupovini ispitati opsežnijim istraživanjima na reprezentativnom uzorku.Online shopping is becoming more prominent in the world but in Croatia as well. Even though Croatians are adapting to the trend of online shopping, it has not been researched which goods and services they prefer to buy online, and which do they prefer to buy offline. The aim of the paper is to research Croatian consumer habits when buying online and offline in correlation with the type of product or service. Procedure: On a suitable sample of 108 examinees between the ages of 18 and 60+, an online questioner was used with 64 particles where, with the demographic data, information was acquired concerning the preferences of online and offline shopping with regards to: The way goods are bought, The frequency of bought goods from Croatian internet stores, Thoughts about product pricing when shopping Importance of touch and product diversity Assessing the ease of returning a product Comparing product and service quality The practicality of being informed and shopping This data referred to the eight product or service categories; food and non-alcoholic drinks, clothes and footwear, household items, health, communications and application, recreation and culture, education, restaurants and hotels. Results: From the given results a statistically significant correlation was found between the habits of online shopping and age. This also indicated that the chronological age was significantly connected with education but also suspicion concerning online purchases. The results are different to what Lyera and Eastman (2006) found which was that more literate and technology aware older people tend to use online shops more. Sivansan, Monisha et. al. (2017) have found out that women buy more than men online and also that people older than 35 years of age buy items online more rarely compared to younger people which is not the case in our research data which suggests iv that there are no gender differences concerning online shopping habits. Conclusion: Croatian customers from our sample show greater insecurity towards online shopping as age increases, men and women have the same preference towards online shopping depending on their financial status. Since the research was done on a relatively small sample, in order to generalize the results further research needs to be done on a bigger sample

Acoustic properties and phylogenetic relationships of gobies from the family Gobiidae (Teleostei; Gobiiformes)

Glavoči su najbrojnijih skupina riba zrakoperki. Također, oni su jedna od akustički najistraživanijih skupina zrakoperki današnjice, sa 23 poznate vrste koje se glasaju. U sklopu ove disertacije, u četiri znanstvene publikacije prvi je put istražena, upotrebom bioakustičkih metoda i analiza, sposobnost stvaranja zvukova i vokalni repertoar glavoča linije Gobius Neogobius melanostomus, Neogobius fluviatilis i Ponticola kessleri, kao i Perccottus glenii (Odontobutidae). Nadalje, ovom su disertacijom istražene anatomske strukture uključene u proces produkcije zvukova kod rotana, a rezultati su pokazali kako se mehanizam najvjerojatnije temelji na kontrakcijama kranijalno-pektoralnih mišića. Upotrebom molekularnih analiza koje uključuju metode filogenetske rekonstrukcije s mitohondrijskim i jezgrenim genetičkim biljezima, rekonstruirani su odnosi vokalnih glavoča linije Gobius te istražena korelacija između genetičke i akustičke divergencije. Rezultati ove disertacije naglašavaju kako su zvukovi glavoča specifični za pojedinu vrstu, dok njihova interspecijska akustička divergencija prati genetičku, što pokazuje kako evolucija zvukova i genotipova prati isti obrazac.Gobies are the most numerous fish group. They are also one of the most investigated acoustic cluster of actinopterygian fish nowadays, with 23 species vocally tested. In this dissertation, represented through four scientific publications, the acoustic communication and vocal repertoire was investigated in Gobius-lineage gobies Neogobius melanostomus, Neogobius fluviatilis and Ponticola kessleri, as well as in Perccottus glenii (Odontobutidae), using standardized bioacoustic methods and analyses. The presented dissertation investigated the anatomical structures involved in the sound production, and the conducted analyses indicate that the sonic mechanism could be based on the contractions of cranio-pectoral muscles. By using phylogenetic analyses with a multilocus approach, we reconstructed the interspecific relationships between vocal gobies from Gobius-lineage and correlated the acoustic and genetic divergences. Results of this dissertation emphasize that goby sounds are truly species-specific, while their interspecific acoustic divergence follows the genotypic divergence, which could indicate that acoustic signals in gobies from Gobius-lineage carry phylogenetic signal

Acoustic properties and phylogenetic relationships of gobies from the family Gobiidae (Teleostei; Gobiiformes)

Glavoči su najbrojnijih skupina riba zrakoperki. Također, oni su jedna od akustički najistraživanijih skupina zrakoperki današnjice, sa 23 poznate vrste koje se glasaju. U sklopu ove disertacije, u četiri znanstvene publikacije prvi je put istražena, upotrebom bioakustičkih metoda i analiza, sposobnost stvaranja zvukova i vokalni repertoar glavoča linije Gobius Neogobius melanostomus, Neogobius fluviatilis i Ponticola kessleri, kao i Perccottus glenii (Odontobutidae). Nadalje, ovom su disertacijom istražene anatomske strukture uključene u proces produkcije zvukova kod rotana, a rezultati su pokazali kako se mehanizam najvjerojatnije temelji na kontrakcijama kranijalno-pektoralnih mišića. Upotrebom molekularnih analiza koje uključuju metode filogenetske rekonstrukcije s mitohondrijskim i jezgrenim genetičkim biljezima, rekonstruirani su odnosi vokalnih glavoča linije Gobius te istražena korelacija između genetičke i akustičke divergencije. Rezultati ove disertacije naglašavaju kako su zvukovi glavoča specifični za pojedinu vrstu, dok njihova interspecijska akustička divergencija prati genetičku, što pokazuje kako evolucija zvukova i genotipova prati isti obrazac.Gobies are the most numerous fish group. They are also one of the most investigated acoustic cluster of actinopterygian fish nowadays, with 23 species vocally tested. In this dissertation, represented through four scientific publications, the acoustic communication and vocal repertoire was investigated in Gobius-lineage gobies Neogobius melanostomus, Neogobius fluviatilis and Ponticola kessleri, as well as in Perccottus glenii (Odontobutidae), using standardized bioacoustic methods and analyses. The presented dissertation investigated the anatomical structures involved in the sound production, and the conducted analyses indicate that the sonic mechanism could be based on the contractions of cranio-pectoral muscles. By using phylogenetic analyses with a multilocus approach, we reconstructed the interspecific relationships between vocal gobies from Gobius-lineage and correlated the acoustic and genetic divergences. Results of this dissertation emphasize that goby sounds are truly species-specific, while their interspecific acoustic divergence follows the genotypic divergence, which could indicate that acoustic signals in gobies from Gobius-lineage carry phylogenetic signal

Acoustic properties and phylogenetic relationships of gobies from the family Gobiidae (Teleostei; Gobiiformes)

Glavoči su najbrojnijih skupina riba zrakoperki. Također, oni su jedna od akustički najistraživanijih skupina zrakoperki današnjice, sa 23 poznate vrste koje se glasaju. U sklopu ove disertacije, u četiri znanstvene publikacije prvi je put istražena, upotrebom bioakustičkih metoda i analiza, sposobnost stvaranja zvukova i vokalni repertoar glavoča linije Gobius Neogobius melanostomus, Neogobius fluviatilis i Ponticola kessleri, kao i Perccottus glenii (Odontobutidae). Nadalje, ovom su disertacijom istražene anatomske strukture uključene u proces produkcije zvukova kod rotana, a rezultati su pokazali kako se mehanizam najvjerojatnije temelji na kontrakcijama kranijalno-pektoralnih mišića. Upotrebom molekularnih analiza koje uključuju metode filogenetske rekonstrukcije s mitohondrijskim i jezgrenim genetičkim biljezima, rekonstruirani su odnosi vokalnih glavoča linije Gobius te istražena korelacija između genetičke i akustičke divergencije. Rezultati ove disertacije naglašavaju kako su zvukovi glavoča specifični za pojedinu vrstu, dok njihova interspecijska akustička divergencija prati genetičku, što pokazuje kako evolucija zvukova i genotipova prati isti obrazac.Gobies are the most numerous fish group. They are also one of the most investigated acoustic cluster of actinopterygian fish nowadays, with 23 species vocally tested. In this dissertation, represented through four scientific publications, the acoustic communication and vocal repertoire was investigated in Gobius-lineage gobies Neogobius melanostomus, Neogobius fluviatilis and Ponticola kessleri, as well as in Perccottus glenii (Odontobutidae), using standardized bioacoustic methods and analyses. The presented dissertation investigated the anatomical structures involved in the sound production, and the conducted analyses indicate that the sonic mechanism could be based on the contractions of cranio-pectoral muscles. By using phylogenetic analyses with a multilocus approach, we reconstructed the interspecific relationships between vocal gobies from Gobius-lineage and correlated the acoustic and genetic divergences. Results of this dissertation emphasize that goby sounds are truly species-specific, while their interspecific acoustic divergence follows the genotypic divergence, which could indicate that acoustic signals in gobies from Gobius-lineage carry phylogenetic signal

Early Development of the Endemic Delminichthys krbavensis (Leuciscidae, Cypriniformes) from a Karstic Field in Croatia

This is the first report of the early development for the endemic Krbava minnow Delminichthys krbavensis from a karstic field in Croatia, and the first report of any species of the genus Delminichthys. The description is based on basic morphometric measures and meristic counts during a 48-day observation of embryos and larvae acquired from successful spawning and rearing in an aquarium. The mean total length of larvae at the time of hatching was 3.12 mm. Mouth opening and independent feeding and intestinal function were observed after day 11 post-hatching (PH) at which time the yolk sac was completely absorbed in all individuals. Flexion of the urostyle began after day 18 PH and was completed by day 23 PH. Pectoral fins developed on day 7 PH, pelvic fins begin to develop by day 44 PH and the formation of caudal, dorsal and anal fin was complete by day 48 PH, when individuals presented the full set of soft rays. Understanding its early development is particularly valuable in assessing the environmental impacts on this endangered species and is essential for its effective monitoring and conservation

A Review of Extant Croatian Freshwater Fish and Lampreys

A checklist of the freshwater fish fauna of Croatia is presented for the first time. It is based on 1360 publications of historical and recent data in the literature. According to the literature review, there were 137 fish species in 30 families and 75 genera recorded in Croatia. The checklist is systematically arranged and provides distributional data of the freshwater fish fauna as well as whether the species is endemic, introduced or translocated