Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Otolith features and growth of juvenile Opsaridium microcephalum (Pisces: Cyprinidae) from the southwestern shoreline of Lake Malawi

Otolith features and growth of juvenile Opsaridium microcephalum (Pisces: Cyprinidae) from the... Sanjika, Opsaridium microcephalum, were collected from two sites (Nkhotakota and Chia) along the southwestern shoreline of Lake Malawi. The sagitta of the otolith was arrowhead-shaped with an obvious nucleus. Increments in the sagittae were observable until the bases of the rostra but invisible in the rostra. The asteriscus was oval-shaped with an ambiguous nucleus, leading to difficulty in identifying the first increment. The lapillus was ‘a’-shaped with an obvious nucleus and increments were observable from the nucleus to the margin. The lapillus was therefore considered the most suitable structure for interpreting daily growth increments in this species. The estimated hatching months of fish based on lapilli increment counts were from November to July, suggesting that this species has a long breeding period of at least eight months per year. The growth rate of fish born in the rainy season (0.74 mm TL per day) was higher than those in the dry season (0.56 mm TL per day). This growth difference was considered to be due to the difference in water temperature in the lake. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png African Zoology Taylor & Francis

Otolith features and growth of juvenile Opsaridium microcephalum (Pisces: Cyprinidae) from the southwestern shoreline of Lake Malawi

Morioka, Shinsuke
African Zoology , Volume 37 (2): 6 – Oct 1, 2002
Download PDF
6 pages

Otolith features and growth of juvenile Opsaridium microcephalum (Pisces: Cyprinidae) from the southwestern shoreline of Lake Malawi

Abstract

Sanjika, Opsaridium microcephalum, were collected from two sites (Nkhotakota and Chia) along the southwestern shoreline of Lake Malawi. The sagitta of the otolith was arrowhead-shaped with an obvious nucleus. Increments in the sagittae were observable until the bases of the rostra but invisible in the rostra. The asteriscus was oval-shaped with an ambiguous nucleus, leading to difficulty in identifying the first increment. The lapillus was ‘a’-shaped with an obvious nucleus and...
Loading next page...
 
/lp/taylor-francis/otolith-features-and-growth-of-juvenile-opsaridium-microcephalum-wikP00AEmu
Publisher
Taylor & Francis
Copyright
© Zoological Society of Southern Africa
ISSN
2224-073X
eISSN
1562-7020
DOI
10.1080/15627020.2002.11657172
Publisher site
See Article on Publisher Site

Abstract

Sanjika, Opsaridium microcephalum, were collected from two sites (Nkhotakota and Chia) along the southwestern shoreline of Lake Malawi. The sagitta of the otolith was arrowhead-shaped with an obvious nucleus. Increments in the sagittae were observable until the bases of the rostra but invisible in the rostra. The asteriscus was oval-shaped with an ambiguous nucleus, leading to difficulty in identifying the first increment. The lapillus was ‘a’-shaped with an obvious nucleus and increments were observable from the nucleus to the margin. The lapillus was therefore considered the most suitable structure for interpreting daily growth increments in this species. The estimated hatching months of fish based on lapilli increment counts were from November to July, suggesting that this species has a long breeding period of at least eight months per year. The growth rate of fish born in the rainy season (0.74 mm TL per day) was higher than those in the dry season (0.56 mm TL per day). This growth difference was considered to be due to the difference in water temperature in the lake.

Journal

African Zoology – Taylor & Francis

Published: Oct 1, 2002

Keywords: Sanjika; Otolith increment analysis; Growth

There are no references for this article.