IR Home
MEPS
Home
Editors
Forthcoming
Information
Subscribe
Journals
Home
MEPS
AME
CR
DAO
ESEP
ESR
Search
Subscribe
Book Series
EE Books
Top Books
ESEP Books
Order
EEIU Brochures
(pdf format)
Discussion Forums
Home
Research
IR Research
Institutions
International Ecology Institute
Eco-Ethics International Union
Foundation
Otto Kinne Foundation
 | |
MEPS 290:119-134 (2005)
|
Abstract
|
Feeding ecology of dominant larval myctophids in an upwelling area of the Humboldt Current
Laura Rodríguez-Graña1, 3,*, Leonardo Castro3, Marcelo Loureiro2,Humberto E. González4,5, Danilo Calliari1
1Sección Oceanología, and 2Sección Vertebrados, Facultad de Ciencias, Universidad de la República, Iguá 4225, CP 11400, Montevideo, Uruguay
3Laboratorio de Oceanografía Pesquera
y Ecología Larval, Departamento de Oceanografía, and 4Centro de InvestigacionesOceanográficas del Pacífico Sur-Oriental (COPAS), Universidad de Concepción, PO Box 160-C, Concepción,
Chile
5Instituto de Biología Marina, Universidad Austral de Chile, PO Box 567, Valdivia, Chile
*Email: laurod@fcien.edu.uy
ABSTRACT: The feeding of 2 sympatric larval myctophids, Diogenichthys laternatus and Triphoturus mexicanus aff. oculeus, was analyzed in an upwelling area off northern Chile (23°S, 71°W). Diel feeding period, feeding
incidence, feeding selectivity and diet overlap was estimated under different environmental conditions: coastal and oceanic areas and 2 depth strata in summer and winter 1997. Analyses were based on larval stomach contents and microplankton abundance
estimates. Larval tooth morphology and relationships between larval length, mouth width and prey size were explored. Both species fed on the most abundant microplankton layer during daylight, and both preferred copepods and nauplii, although the diet of
D. laternatus was more diverse. As expected, the diets of these species tended to overlap in periods and areas where food was more abundant, but diets differed under conditions of low food availability. The 50 to 100 mm size range dominated
the size spectrum of ingested prey in both species. The smallest prey width was constant for the entire range of larval sizes. The largest prey width was variable both within and between species, and increased with larval size. Regression analyses of
mouth size and body length showed a potential relationship in D. laternatus and a linear relationship in T. mexicanus aff. oculeus. Prey ingested by D. laternatus were wider than those ingested by T. mexicanus aff.
oculeus at equal larval sizes. The species presented differences in dentition patterns (hook-like teeth and pharyngeal structures in D. laternatus, conical teeth in T. mexicanus aff. oculeus). Opportunistic feeding and the
feeding characteristics of both species should favor persistence and high abundances in the upwelling area of the Humboldt Current.
KEY WORDS: Diogenichthys laternatus · Triphoturus mexicanus · Triphoturus oculeus · Larval feeding · Myctophid · Upwelling · Humboldt Current
Full text in pdf format
Published in MEPS Vol.
290
(2005) on April 13
Print ISSN: 0171-8630; Online ISSN: 1616-1599.
Copyright © Inter-Research, Oldendorf/Luhe, 2005
|
