|Scientific Name:||Callorhinchus callorynchus|
|Species Authority:||(Linnaeus, 1758)|
|Taxonomic Notes:||Molecular studies are required to determine the level of genetic distinctness between the species in the Southwest Atlantic and the Southeast Pacific.|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Dagit, D.D., Chiaramonte,G.E., Romero, M., Di Giácomo, E. & Acuña, E.|
|Reviewer(s):||Kyne, P.M., Fowler,S.L., Compagno, L.J.V., Cavanagh, R.D. & Valenti, S.V. (Shark Red List Authority)|
Callorhinchus callorhynchus is widespread around southern South America off Peru, Chile, Argentina, Uruguay and southern Brazil. It is captured year-round as part of commercial bottom trawl fisheries in Argentina, Chile and Peru, mostly at depths of 90 to 130 m. This species is also captured on lines and a small recreational fishery exists. C. callorhynchus appears to be relatively abundant throughout its range. Data on fishery trends from Argentina indicates that landings of this species appear to be fluctuating: landings increased from 1992 to a peak in 1999 followed by an abrupt fall in the 2000 to 2002 period, before rising again from 2002 to 2004. This "boom and bust cycle" , is similar to that observed in other species of Callorhinchus (such as C. milii) that have been sustainably fished, although it should be noted that this was under strict management. Although landings in Chile appeared to decline from 1992 to 2004, it is thought that this is the result of shifting fishing effort between Hake and C. callorhynchus. In Peru, C. callorhynchus is also caught by beach seine in a multi-species fishery. This species is only of minor importance to fisheries in Peru and landings are unsteady but a slight decline in its landings from the beach seine fishery has been observed. While additional fishery data from Brazil and Uruguay may well present regional differences in relative abundance and/or declines related to local fishing trends; at present no such data are available. Given that this species appears to be exhibiting the same "boom and bust cycle" observed in C. milii in Australia and New Zealand (which has been sustainably fished since the 1960s) in Argentina, that the apparent decline in Chilean landings is attributed to a shift in effort, and that Callorhinchus species are relatively productive, it is not considered to be at immediate threat and it is currently assessed as Least Concern. However, given that this species is fished throughout its range it is important that the situation is monitored closely and this assessment may need to be re-visited in the near term.
|Range Description:||Ranges from Southern Brazil to Southern Patagonia in the southwest Atlantic and from Peru and Chile in the southeast Pacific. It has also been reported from the Argentine section of the Beagle Channel, Tierra del Fuego (López et. al. 2000).|
Native:Brazil; Chile; Peru; Uruguay
|FAO Marine Fishing Areas:|
Atlantic – southwest; Pacific – southeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Very little is known with regard to population size and structure of C. callorhynchus throughout its range. Studies of C. callorhynchus off the coast of Argentina indicate that there may be separate populations which appear to be related to food abundance and availability. Aggregations by sex and size have also been observed. Data are not available for regions outside of the Gulf of San Matías.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Depth range is generally from nearshore to about 170 m, however there are reported captures of this species from 481 m off Chile. This may indicate that the species occupies and/or migrates to deeper waters than currently reported, or may occupy different depth ranges in different parts of its range. A coastal and continental shelf dweller that likely occupies a variety of rocky, sandy and/or muddy bottoms throughout its range. |
Maximum recorded size for females is 102 cm total length (TL) and 85 cm TL for males. Like the related species C. millii and C. capensis, C. callorhynchus probably has an early onset of sexual maturity and relatively high fecundity. C. callorhynchus is oviparous with spawning and reproductive behaviors similar to those described for C. milii and C. capensis. Mating and spawning occurs in spring and early summer with a primary spawning season from July to November. In the Gulf of San Mathías, Argentina, where most work on this species has been conducted, spawning migrations into shallow waters have been observed with eggs collected at depths of 20 to 40 m, but also as deep as 104 m (Di Giácomo and Perier 1994).
The diet (Di Giácomo et al. 1994) consists primarily of shelled invertebrate prey, particularly bivalve molluscs, gastropods and polychaetes. Differences in the diet of males and females and between juveniles and adults are attributed to prey availability and morphology and behavior of predators (e.g., tooth plates of juveniles are not as large or strong as those of adults).
The following morphometric details are given as standard length (SL) measurements, which refers to the distance from the tip of the snout to the origin of the upper caudal lobe. Females mature at 49 cm SL and males at 40 cm SL (Di Giácomo and Perier 1994). The maximum recorded size for C. callorhynchus is 102 cm total length (TL) (Di Giácomo and Perier 1994). Size at birth is 13 cm TL and gestation time is probably in the region of 6 to 12 months.
C. callorhynchus is exploited locally throughout its range primarily as a component of bottom trawl fisheries, typically fished at depths of 90 to 130 m. Although captured year-round, there does appear to be seasonal migrations to shallower waters in the spring and autumn for spawning with a return to deeper waters during the winter. May be targeted more specifically in some regions. Also caught recreationally using lines. In Argentina this species is primarily caught as bycatch in the hake (Merluccius hubbsi) fishery.
Overfishing may potentially threaten this species based on recent declines in numbers landed in Argentina (landings increased from 479 mt in 1992 to a peak in 1999 of 1,979 mt followed by an abrupt fall in the 2000-2002 periods, followed by another increase to 1,712 mt in 2003 followed by a slight decline to 1,554 mt in 2004) (Di Giácomo and Perier 2005). This 'boom and bust' cycle has been observed in other Callorhinchus species that have been sustainably fished (D. Didier pers. obs.) however it should be noted that this was under strict management thus caution must be applied in any such comparisons. Additional data, particularly from other parts of the range, are needed to verify if this is a singular localized event or indicative of a trend in declining numbers of this species throughout its range.
In Chile, total landings increased from ~1,000 t to between ~3,000 t and ~4,500 t between 1990 and 1992, followed by a sharp decline to ~1,000 t again in 1995. However, it is thought that this is the result of a shift in effort to targeting Hake. Landings of C. callorhynchus have fluctuated ~1,500 t to ~500 t since 1995.
In Peru C. callorhynchus is also caught by beach seine in a multi-species fishery. This species is of minor importance to fisheries in Peru and data from landings were not recorded prior to 1996. An average catch of 7.81 mt per year was taken off Peru between 1996 and 2003, ranging from 11.87 mt in 1998 to 4.54 mt in 2000. The landings are unsteady but a slight decline is observed.
Very little information is currently available with regard to specific regulations and conservation measures although as part of a bycatch fishery C. callorhynchus may not be subject to rigorous regulations. Any regulations and conservation measures will likely vary by country and region.
Note that management (continued monitoring of CPUE and responding by altering TAC's) of another Callorhinchus species (C. milli) in New Zealand and Australia have resulted in a sustainable fishery.
|Citation:||Dagit, D.D., Chiaramonte,G.E., Romero, M., Di Giácomo, E. & Acuña, E. 2007. Callorhinchus callorynchus. The IUCN Red List of Threatened Species 2007: e.T63107A12606367.Downloaded on 21 October 2016.|
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