Dužinsko-maseni odnos crvenoperke Rutilus rutilus (Linnaeus, 1758) u jezeru Volvi (sjeverna Grčka)

Length-weight relations (LWRs) and different indices of condition factor for roach from Lake Volvi (Northern Greece) were estimated. Results showed that roach are heavier of a given length in Lake Volvi than in other areas worldwide, with females exhibited higher weight than males of the same length. Significant differences (P<0.05) of LWRs were also exhibited between sexes depending on month. CLARK condition factor peaked at the end of summer displaying no significant difference between sexes, whereas the other three estimated condition factors (Allometric, FULTON, LE CREN) peaked in winter. The estimation of different proxies of condition factor disaggregated by sex might reduce the uncertainty raised by the estimation of fish growth.Procijenjeni su odnosi duljine i težine (LWR) i različiti indeksi uvjeta za crvenperku u jezeru Volvi (sjeverna Grčka). Rezultati su pokazali da je ženka crvenperke iz jezera Volvi jednake dužine kao i primjerci iz cijelog svijeta teža nego u drugim područjima širom svijeta. Također, ženke su pokazivale veću težinu od mužjaka iste duljine.Značajne razlike (P <0,05) LWR-a također su bile između spolova, ovisno o mjesecu. Clarkov kondicijski čimbenik dosegnuo je vrhunac krajem ljeta, ne pokazujući značajnu razliku između spo-lova, dok su ostala tri procijenjena čimbenika stanja (alometrija, Fulton, Le Cren) dosegla vrhunac zimi. Procjena različitih zastupljenih faktora stanja prema spolu može smanjiti nesigurnost koja se javlja procjenom rasta ribe

Ecology of roach (Rutilus rutilus L.) of lake Volvi

This study refers to the ecology of roach (Rutilus rutilus L.), at the ecosystem of lake Volvi in Greece. The physicochemical water characteristics of its biotope were studied and specifically: temperature, conductivity, clarity, dissolved oxygen, pH, total hardness, sulfuric salts, orthophosphate salts, nitrogen compounds (ammonia-nitrogen, nitrates, nitrites), biological oxygen demand (B.O.D5) and the chlorophyll-a. Totally 3,384 specimens were captured using nets The age determination was based on scale<s annual ring formation and the time of those rings formation was found to occur in April. The older roach specimen was found to be eight years old. The annual growth of roach was calculated according to length as well as weight, based upon the observed and calculated values, by the backcalculation growth method. The application of this method is based on the relationship of the fork length to the scale radius. It was found out that males overtake female<s fork length only during the first year. The maximum annual growth, which was found to be 71 mm, was observed during the first year of their lives. The final length (L@), that roach can attain in lake Volvi was calculated to be 185.60 mm for males and 277.18 mm for females. The length – weight relationship it showed that roach<s growth is allometric. The condition factor showed that the female values were higher than the male ones and the reduction value index occurs from February to May for both sexes. The study of reproduction, was carried out on mature females, according Kesteven< s index. Compared with the other ecosystems, the roach mature earlier, the male in the age of one year and female one year later. The reproduction period is short, from the end of March until early April. The mean absolute fecundity was calculated to be 8,102 eggs which was higher than other ecosystems. The mean relative fecundity was 250.75 eggs/g of body weight and was independent for length, weight and the age. Analogy of sex indicates that there was advantage of the male fish on the female at the small length classes and ages. The fast matureness of male at the small length classes probably covers the male generative of population or the other hand the greater female increase the production of eggs. The total mortality was calculated with two methods, the catch curve (male 1,231, female 1,019 and both sexes 1,202), and linearized catch curve based on length composition data (male 1,140, female 0,921 and both sexes 1,094). The natural mortality was calculated with two independently methods, Pauly< method (male 0,451, female 0,306 and both sexes 0,241) and methods dependent on the gonadosomatic index (0,293). The roach in lake Volvi according to present conditions, don’t face any population problem until 3-4 years of age The year production of roach was equal to the 2/3 biomass, the female were more productive in comparison to the male. From produced biomass , the 39% was obtained fishing by fisheries and the other lost in natural mortality. Yield per recruit gave 23.093 g /roach according to fishing condition. This means that the fishing management gives as the best yiel

Πολιτισμικά στοιχεία και ιδιαιτερότητες αφρικανών γυναικών κατά τη διάρκεια της εγκυμοσύνης

Η παρούσα ερευνητική εργασία, έχει σαν σκοπό να μελετήσει τις παραδόσεις και τα πολιτισμικά στοιχεία των Αφρικανών γυναικών κατά τη διάρκεια της εγκυμοσύνης τους και να διερευνήσει τις συνθήκες που επικρατούν, αλλά και τις συνήθειές τους, όσον αναφορά την εγκυμοσύνη και τον τοκετό. Η έρευνα έχει ανθρωπιστική βάση και απορρέει από άμεσες πραγματικές συνεντεύξεις γυναικών. Τα πορίσματα της έρευνας αφορούν, τις παραδόσεις που έχουν στην Αφρική, σχετικά με την εγκυμοσύνη και τον τοκετό, τα παραδοσιακά φαγητά, τα βότανα και τους λόγους που τα χρησιμοποιούν στην εγκυμοσύνη. Επίσης, αναφέρει τις παραδόσεις σχετικά με τον πλακούντα, αλλά και τις τελετές κατά τη διάρκεια και μετά την εγκυμοσύνη. Παράλληλα, εξετάστηκαν, οι παράγοντες που συντελούν στο που θα γεννήσει μια γυναίκα, σε περιοχές της Αφρικής και πώς τους επηρεάζει η παράδοση στην απόφασή τους αυτή. Ολοκληρώνοντας, εξετάστηκε αν οι γυναίκες θα ήθελαν και εδώ στην Ελλάδα να συνεχίσουν τις παραδόσεις που έχουν καθεμία ξεχωριστά στη χώρα τους. Τα αποτελέσματα της έρευνας καταδεικνύουν πως, οι παραδόσεις για τις γυναίκες της Αφρικής, αποτελούν αναπόσπαστο κομμάτι της καθημερινότητάς τους. Η χρήση παραδοσιακών βοτάνων, φαγητών, αλλά και τεχνικών μασάζ είναι διαδεδομένες στις κοινότητες της Αφρικής. Ακόμη και άλλες παραδόσεις σχετικά με την εγκυμοσύνη και τον τοκετό. Βέβαια, κάποιες από αυτές τις πολιτισμικές ιδιαιτερότητες, τις χρησιμοποιούν λόγω μη πρόσβασης στο σύστημα υγείας και αδυναμίας παρακολούθησης της κύησης, από επιστήμονες υγείας. Εξαιρετικής σημασίας κρίνεται η διεξαγωγή ανάλογων ερευνών, οι οποίες θα βασίζονται στην εναρμόνιση των παραδόσεών τους, κατά την κύηση και τον τοκετό και εδώ στην Ελλάδα.The purpose of this study was to explore the traditions and cultural beliefs of African women, during their pregnancy. The research is humanitarian based; African pregnant women purposefully selected and interviewed individually. The findings of the research concern the traditions in Africa about pregnancy and childbirth, traditional foods, herbs and the reasons to use them during the pregnancy. It also mentions placental traditions, ceremonies during and after the pregnancy. At the same time, African women were questioned about the factors that contribute to the decision about where to give birth, and the significance of tradition among them. It was examined whether these women here in Greece would like to continue the traditions they have in Africa. This study concluded that the cultural beliefs and the traditions are very important for Africa women. They use traditional herbs, foods, massage techniques and other traditions for the pregnancy and the childbirth. It is a fact that the inaccessibility to the health system is of great importance in the creation of the need for these traditions and cultural beliefs. It is important to conduct research based on the harmonization of their traditions during pregnancy and childbirth here in Greece