Sustainability of Orange Roughy Population

2019 ◽  
Vol 28 (3) ◽  
pp. 647-661
Author(s):  
Sampurna Sengupta ◽  
Pritha Das
Keyword(s):  
Orange Roughy

Age determination and growth of orange roughy (Hoplostethus atlanticus): a comparison of annulus counts with radiometric ageing

1995 ◽  
Vol 52 (2) ◽  
pp. 391-401 ◽  
Author(s):  
David C. Smith ◽  
Simon G. Robertson ◽  
Gwen E. Fenton ◽  
Stephen A. Short
Keyword(s):  
Age Determination ◽  
Percentage Reduction ◽  
Age At Maturity ◽  
Otolith Growth ◽  
Two Stage ◽  
Orange Roughy ◽  
Mass Growth ◽  
Hoplostethus Atlanticus ◽  
Age Estimates ◽  
Radiometric Data

Ages of orange roughy (Hoplostethus atlanticus) determined by two methods (counting annuli on the surface of whole and in longitudinally sectioned otoliths) were similar up to maturity. Beyond maturity, age estimates from sectioned otoliths exceeded those from whole otoliths. Maximum recorded age was 125 years for an individual 41 cm standard length (SL), and age at maturity was estimated to be 25 years (30–32 cm SL). These are consistent with ages estimated previously by radiometric methods. Results demonstrated a two-stage linear relationship between otolith weight and age that confirmed the two-stage otolith mass growth model previously used in radiometric ageing. However, in the radiometric analyses the reduction in otolith growth was arbitrarily estimated at 45% of the immature rate whereas annuli data demonstrated a reduction after maturity to 62% of the immature rate. The new estimates of otolith mass growth rate were incorporated into the radiometric data and ages recalculated, which reduced age estimates for 38–40 cm SL fish from 77–149 to 59–101 years. The radiometric data were also recalculated using only the percentage reduction in otolith growth after maturity, giving the radiometric age of 125 ± 9 years for the oldest fish.

The morphology and chemistry of the scales of the orange roughy and the smooth and spiky oreo dories

1991 ◽  
Vol 23 (5) ◽  
pp. 677-708 ◽  
Author(s):  
R.W. Gauldie ◽  
G. Coote ◽  
I.F. West ◽  
K.P. Mulligan
Keyword(s):  
Orange Roughy

Habitat, behaviour and colour patterns of orange roughy Hoplostethus atlanticus (Pisces: Trachichthyidae) in the Bay of Biscay

2002 ◽  
Vol 82 (2) ◽  
pp. 321-331 ◽  
Author(s):  
Pascal Lorance ◽  
Franz Uiblein ◽  
Daniel Latrouite
Keyword(s):  
Food Resource ◽  
High Water ◽  
Foraging Strategy ◽  
Fine Tuning ◽  
Bay Of Biscay ◽  
Orange Roughy ◽  
North East ◽  
Peripheral Areas ◽  
Colour Patterns ◽  
Red Coloration

Analyses of 13 submersible dives on the continental slope of the Bay of Biscay (north-east Atlantic) showed that: (i) orange roughy formed dense aggregation of more than 4000 individuals per ha close to the bottom of a small underwater canyon. In all other study areas only a few individuals were observed. Orange roughy aggregations are probably associated with areas of high water mass movements and mixing; (ii) most individuals observed within this aggregation or in its peripheral areas were behaviourally inactive and could be approached with the submersible at close distance; (iii) a large number of these orange roughy showed a completely pigmentless white, or weak red coloration, never observed from specimens caught in trawls. Two individuals which were disturbed by the submarine changed from white to the ‘typical’ red coloration.These observations suggest fine tuning of the foraging strategy and life cycle of the species. It is speculated that, as an active predator of a sparse food resource, orange roughy has developed adaptations to exploit areas with specific hydrological conditions which offer high prey encounter rates and shelter during metabolic relaxation phases between foraging trips.

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