New Zealand Journal of Marine and Freshwater Research abstracts

---

Non-diadromous recruitment in coastal populations of common bully (Gobiomorphus cotidianus)

Gerard P. Closs

Department of Zoology
University of Otago
P.O. Box 56, Dunedin
New Zealand
email: gerry.closs@stonebow.otago.ac.nz

Melvin Smith

School of Biological Sciences
University of Wales Swansea
Singleton Park
Swansea SA2 8PP, Wales
United Kingdom

Bernard Barry
Andreas Markwitz

The Institute of Geological and Nuclear Sciences
Rafter Laboratory
P.O. Box 31 312, Lower Hutt
New Zealand

Abstract   Otolith microchemistry of common bullies (Gobiomorphus cotidianus) collected from the lower reaches of the Mataura, Clutha, and Taieri/Waipori River systems of New Zealand was examined using particle induced X-ray emission (PIXE). High strontium:calcium (Sr:Ca) ratios in otolith cores relative to otolith edges suggested either diadromous or estuarine-reared common bullies are present in all three systems, including fish collected from Clydevale (50 km inland) on the Clutha River. However, constant or slightly variable Sr:Ca ratios from otolith core to edge, suggesting a non-diadromous life history, were also observed in fish from the lower Mataura and Taieri/Waipori systems, even where access to the sea was continuously available. The results suggest that diadromy in common bully may be facultative, and that a proportion of the common bully population may be non-diadromous in river systems where suitable larval/juvenile rearing habitat is present.

Keywords   otolith microchemistry; diadromy; migration; Sr:Ca ratio; strontium; PIXE

M02074 Received 18 September 2002; accepted 8 January 2003; Published 20 June 2003
New Zealand Journal of Marine and Freshwater Research, 2003, Vol. 37: 301-313
0028-8330/03/3702-0301 $7.00 © The Royal Society of New Zealand 2003

PDF file of entire paper: Print-quality (327K) | screen-quality (119K)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page