Yazar "Akamca, Erhan" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim
    Öğe
    Some biological aspects of thornback Ray (Raja clavata L., 1758) in the Southeastern Black Sea
    (2005) Demirhan, Sefa Ayhan; Engin, Semih; Seyhan, Kadir; Akamca, Erhan
    Feeding, reproduction and growth of thornback ray {Raja clavata L., 1758) were studied from the South-eastern Black Sea near the Georgian border. Females made up 56% and males 44% of the individuals. The total length (TL) of females ranged from 34.3 to 88.2 cm (21.5-62.7 cm disc width (DW)), and males from 48.0 to 95.0 cm (35.5-61.0 cm DW)). The total length-weight (TL-W), disc width-weight (DW-W) and total length-disc width (TL-DW) relationships were $W=0.001TL^{3.42}$ ( $r^2$ =0.91), $W=0.008DW^{3.21}$ ( $r^2$ =0.94) and DW=0.65TL+2.47 ( $r^2$ =0.88), respectively, for the sexes combined. The total length at 50% maturity (TL50) was about 64.03 cm (44.24 cm DW) for males and about 66.72 cm (47.27 cm DW) for females. Out of 50 stomachs examined, 70% of them were empty. The prey items found in the stomachs were anchovy (Engraulis encrasicolus), horse mackerel (Trachurus trachurus), whiting (Merlangus merlangus euxinus), goby (Gobius sp.), shrimps (Upogobia pusilla, Crangon crangon) and unidentified crab.
  • Küçük Resim
    Öğe
    Spatial Distribution and Activity Pattern of the Ghost Crab, Ocypode cursor (L., 1758) in Yumurtalik Bay, North-Eastern Mediterranean-Turkey
    (Medwell Online, 2009) Tureli, Canan; Duysak, Oender; Akamca, Erhan; Kiyagi, Volkan
    Spatial distribution and activity pattern of Ocypode cursor (L., 1758) were studied for 2 years (2000-2001) in 40x15 m sand beach of Yumurtalik Bay in Turkey. Analysis of frequency distributions of the ghost crab population was based on indirect census, with burrow diameter measurement. Burrow diameter was a good estimator of crab size. Burrow diameter/carapace length and length/width relationships were estimated from samples obtained by excavating burrows and individual capture by trap. These relationship were adjusted by the following equations, respectively: BD = 0.25+1.13 CL; CW = 2.44+1.13 CL (BD is burrow diameter; CL is carapace length; CW is carapace width). Spatial distribution analysis was performed based on distance and altitude to water line. Most small burrows were found close to the sea, while larger burrows were mostly found in places higher up the beach. O. cursor was absent from the dry portion of the beach next to the dunes. The activity pattern showed that crabs are more activity during night than day-time. Burrow shape also was analysed. These burrows were in L-or j-shapes.
  • [ N/A ]
    Öğe
    Width/Length-Weight and Width-Length Relationships for 8 Crab Species from the North-Eastern Mediterranean Coast of Turkey
    (Medwell Online, 2009) Sangun, Levent; Tureli, Canan; Akamca, Erhan; Duysak, Onder
    In this study, relationships between width/length-weight and width-length by sex and combine were estimated 1133 individuals belonging to 8 species from 5 families in the North-eastern Mediterranean coast of Turkey. Regression coefficient between the regression of W-CL, W-CW and CL-CW for female, male and both were found very high (p<0.001) and the median value of b W-CL were 3.135, 3.132 and 3.081; W-CW were 3.135, 3.132 and 3.081, respectively. The r(2) values ranged from 0.91-0.99.