Dosidicus gigas (Humboldt/Jumbo Squid)

GPO87

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A squid that hardly needs introduction, Dosidicus gigas (aka. the Humboldt Squid aka. jumbo squid aka diablo rojo, is the only member of the genus Dosidicus.



The Humbolt is well know for its aggresive attitude, as well as a behavior known as "flashing". Flashing is a sudden change in color between red and white skin tones, by the quick contraction of chromatophores.

The range of Humbolt Squid were commonly thought to exist primarily in the tropical Pacific. However, in recent years, that distribution has expanded along the entire Coastline of North and South America.

Info at: http://tolweb.org/Dosidicus/19945
 

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Dosidicus Research Papers

Extreme Plasticity in Life‐History Strategy Allows a Migratory Predator (Jumbo Squid) to Cope With a Changing Climate
HJ Hoving, WF Gilly, U Markaida, KJ Benoit‐Bird… - Global Change Biology, 2013
Full article freely available without subscription

Abstract

Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55 cm mantle length) in 1-1.5 years and have supported a major commercial fishery in the Guaymas Basin during the last 20 years. An El Niño event in 2009-2010 was accompanied by a collapse of this fishery, and squid in the region showed major changes in distribution and life history strategy. Large squid abandoned seasonal coastal-shelf habitats in 2010 and instead were found in the Salsipuedes Basin to the north, an area buffered from the effects of El Niño by tidal upwelling and a well-mixed water column. The commercial fishery also relocated to this region. Although large squid were not found in the Guaymas Basin from 2010-2012, small squid were abundant and matured at an unusually small mantle-length (
 

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Danna Staaf's presentation on her Doctorial work with the humboldt squid:

Nerd Nite SF: "Making Squid Babies: Investigations of an Invertebrate Invasion" by Danna Staaf, 3/21/12
 

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Maturation, Age, and Growth Estimation of the Jumbo Squid Dosidicus gigas (Cephalopoda: Ommastrephidae) in the Central Region of the Gulf of California

Casimiro Quiñonez Velázquez , Agustín Hernández Herrera , Iván Velázquez-Abunader and Nicolas Filauri Valencia 2013

Full article requires subscription to BioOne


ABSTRACT In this study, the statolith microstructure of the jumbo squid Dosidicus gigas was used to determine age, individual growth, and changes in sexual maturity off the west coast of the central region of the Gulf of California during 2000 and 2002. The number of individuals sampled was 3,369 with a sex ratio of 1.8:1 (female to male). The size at first maturity (ML50%) in males varied between 46 cm and 56 cm, which was less than that seen in females (76–79 cm). The age of 251 squid was analyzed, and the growth of each sex was described by fitting the Gompertz and logistic models to the age-mantle length (ML) data. The Gompertz model best described the growth of the jumbo squid, and no significant differences were detected between sexes (ARSS, F = 0.73, P = 0.54). The parameters estimated for the combined data were ML∞ = 143.3 cm and g (growth coefficient at inflection point) = 0.004/y and t[SUB]0[/SUB] (age at inflection point) = 259.5 days. From the hatch date frequency distribution, a permanent incorporation of small individuals (ML,
 
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Comprehensive Model of Jumbo Squid Dosidicus gigas Trophic Ecology in the Northern Humboldt Current System
Ana Alegre,Frédéric Ménard,Ricardo Tafur,Pepe Espinoza,Juan Argüelles,Víctor Maehara,Oswaldo Flores,Monique Simier,Arnaud Bertrand
2014 (Full paper)

Abstract
The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters.
 

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Trace element concentrations in the top predator jumbo squid (Dosidicus gigas) from the Gulf of California Joana Raimundo, Carlos Vale,
Rui Rosa 2013 (subscription)


Abstract
Jumbo (or Humboldt) squid, Dosidicus gigas, is a large jet-propelled top oceanic predator off the Eastern Pacific. The present study reports, for the first time, concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd and Pb in gills, mantle and digestive gland of this powerful pelagic squid in the Gulf of California. Zinc and Cu were the most abundant elements. All elements, with the exception of As, were largely stored in digestive gland; particularly Cd that reached concentrations between 57 and 509 µg g−1. Significant relationships between tissues were found for Co (digestive gland–gills), As (gills–mantle) and Cd (digestive gland–mantle). Proportionality of Cd concentrations between mantle and digestive gland suggested that detoxification capacity by digestive gland was insufficient to avoid the transfer of this element to mantle and other tissues. Nonetheless, Cd concentrations in the mantle were always below the regulatory limit and, therefore lack of constraints for human consumption. On the basis of the fishery landings, one may estimate that up to 1 t of Cd can be annually removed by jumbo squid fisheries.

(dwhatley)It would seem removing a ton of Cadmium from the ocean each year may not be a bad thing.
 

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REPRODUCTION AND EARLY LIFE OF THE HUMBOLDT SQUID Danielle Joy Staaf (@Danna ) 2010 (full pdf)

A little Humboldt side reading if you are so inclined :sagrin:

Abstract
Dosidicus gigas, the Humboldt squid, is endemic to the eastern Pacific, and its range has been expanding poleward in recent years. It is a voracious predator of small fish and invertebrates and prominent prey for large fish and mammals, including humans. Very little is known about Humboldt squid reproduction, development, and early life stages. To study the behavior, including dispersal capabilities, of paralarval D. gigas, I analyzed video of animals swimming in the laboratory, and determined that paralarvae are active swimmers that engage in hop-and-sink behavior. Control of the mantle aperture allows them to engage in slow swimming, in which water is leaked through the mantle aperture, and fast jetting, in which the mantle aperture is tightly
closed and all water is expelled through the siphon—as is typical of adult jetting. A theoretical model of squid swimming was built to study the importance of aperture control during the jet cycle. This model predicts that active reduction of the aperture during jetting increases hydrodynamic efficiency, and that squid of large sizes can constrain the risk of embolism by increasing aperture size and decreasing jet frequency to values comparable to empirical measurements. Connectivity among populations of D. gigas throughout the range of this species was assessed with a population genetic approach, in which D. gigas was compared to the co-occurring squid Sthenoteuthis oualaniensis. In D. gigas, only two weakly differentiated populations were evident, with a biogeographic break at 5-6° N. I uncovered four deeply divergent clades in S. oualaniensis, including one which aligns with previous descriptions in the literature of Sthenoteuthis sp. nov. Breaks between clades of S. oualaniensis also occurred at 5-6° N. Range overlap between these two species occurs in the eastern tropical Pacific (ETP), a region both are believed to use as spawning grounds. I looked for paralarvae of D. gigas and S. oualaniensis in surface and subsurface net tows taken in the ETP from 1998 to 2006, and found that abundance was much greater in surface than subsurface tows. I then used a Generalized Linear Model approach to assess the importance of in situ oceanographic variables as predictors of paralarval incidence. ivSea surface temperature was found to be a strong predictor of incidence in both surface and subsurface tows, with the probability of paralarval capture rising
monotonically from near zero at 15 °C to 0.9 at 30 °C. The apparent lack of paralarvae at surface temperatures below 15 °C raises a question of whether D. gigas can spawn in the temperate and even subpolar waters of its expanded range. I conducted in vitro fertilization studies and found the optimal temperature range for successful laboratory development of D. gigas is 15-25° C.
 

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Isolation and characterization of microsatellites for jumbo squid Dosidicus gigas (Ommastrephidae)
ANA M. MILLÁN-MÁRQUEZ1, CÉSAR SALINAS-ZAVALA, PEDRO CRUZ1 and DEVON E. PEARSE 2014 (pdf)

The aim of this study was to isolate and characterize microsatellite markers in D. gigas for later use in population genetic studies. We describe nine polymorphic microsatellites, although most of them have a deficit of heterozygotes apparently caused by a high frequency of null alleles.
 

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Advances in Squid Biology, Ecology and Fisheries: Myopsid Squids. p. 169-206.

Dosidicus gigas (Humboldt or jumbo squid) (Orbigny, 1835) is the largest ommastrephid squid, reaching up to 1.2m mantle length and 65kg in weight. This pelagic squid is endemic to the eastern Pacific Ocean and is particularly abundant in the highly productive waters of the California and Humboldt Current systems, and the Costa Rica Dome upwelling region. The intra-specific population structure of D. gigas is complex, since this species quickly responds to environmental variability driven by El Niño and LaNiña events in both current systems by rapidly changing its biological characteristics, such as somatic and reproductive investment. Oocyte development is asynchronous and the potential fecundity averages around 18\U+2013\21 million oocytes; the maximum value estimated (32 million oocytes) is the largest ever recorded for any cephalopod so far. Hatching occurs between 6 to 9 days after fertilization at 18ÀC, but temperatures below 15ÀC and above 25ÀC do not allow complete embryonic development. D. gigas passes through a posthatching paralarval stage called the rhynchoteuthion and during this stage the two tentacles are fused into a well-developed proboscis. During the paralarval and subsequent juvenile stages Humboldt squid have a monthly growth rate of up to 80 mm in mantle length, and grow up 60 mm per month in the later stages. This is the highest growth rate reported for any cephalopod species, and enables this species to reach the reported maximum mantle lengths in a short lifespan (12 to 24 months). Although the lack of population structure across its large range suggests a high level of gene flow and substantial horizontal migration, specific migratory pathways in the Pacific Ocean have not yet been demonstrated. Long-distance migration is an important element in the lifehistory of Humboldt squid and may be associated with differential growth rates and size and at full maturity. The recent poleward range expansion of D. gigasis likely associated with warmer periods following El Niño/La Niña events, an ongoing expansion of the oxygen minimum zone (OMZ) in the Eastern Pacific, and changing ecosystem interactions including food availability, competition and predation. Humboldt squid feed primarily on small mesopelagic (midwater) fishes, crustaceans, and cephalopods as well as commercially important coastal fishes and squid in the recently expanded range. Typical daily behavior involves vertical migrations from near-surface waters at nighttime to mesopelagic depths above or within the OMZ during the daytime. Whereas the OMZ restricts the depth distribution of many competing vertebrate predators to the upper surface layers due to limited hypoxia tolerance, D. gigas circumvents similar restrictions via metabolic suppression. In addition to its critical role both as prey and predator in the eastern Pacific, D. gigas is an economically important species and the target of what has recently become the world\U+2019\s largest invertebrate fishery.
 

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#11
Chromogenic behaviors of the Humboldt squid (Dosidicus gigas) studied in situ with an animal-borne video package Hannah Rosen, William Gilly,Lauren Bell, Kyler Abernathy,Greg Marshall 2015
free access

Abstract
Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behaviors in free-swimming D. gigas in the Gulf of California with a focus on color-generating (chromogenic) behaviors. We documented two dynamic displays without artificial lighting at depths of up to 70 m. One dynamic pattern, termed ‘flashing' is characterized by a global oscillation (2–4 Hz) of body color between white and red. Flashing was almost always observed when other squid were visible in the video frame, and this behavior presumably represents intraspecific signaling. Amplitude and frequency of flashing can be modulated, and the phase relationship with another squid can also be rapidly altered. Another dynamic display termed ‘flickering’ was observed whenever flashing was not occurring. This behavior is characterized by irregular wave-like activity in neighboring patches of chromatophores, and the resulting patterns mimic reflections of down-welled light in the water column, suggesting that this behavior may provide a dynamic type of camouflage. Rapid and global pauses in flickering, often before a flashing episode, indicate that flickering is under inhibitory neural control. Although flashing and flickering have not been described in other squid, functional similarities are evident with other species.
The paper that goes with this video:
 

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Natural egg mass deposition by the Humboldt squid (Dosidicus gigas) in the Gulf of California and characteristics of hatchlings and paralarvae
danna j. staaf, susana camarillo-coop , steven h.d. haddock , al c. nyack , john payne , cesar a. salinas-zavala , brad a. seibel, lloyd trueblood , chad widmer and william f. gilly 2007 (PDF)

Abstract
The jumbo or Humboldt squid, Dosidicus gigas, is an important fisheries resource and a significant participant in regional ecologies as both predator and prey. It is the largest species in the oceanic squid family Ommastrephidae and has the largest known potential fecundity of any cephalopod, yet little is understood about its reproductive biology. We report the first discovery of a naturally deposited egg mass of Dosidicus gigas, as well as the first spawning of eggs in captivity. The egg mass was found in warm water (25 –278C) at a depth of 16 m and was far larger than the egg masses of any squid species previously reported. Eggs were embedded in a watery, gelatinous matrix and were individually surrounded by a unique envelope external to the chorion. This envelope was present in both wild and captive-spawned egg masses, but it was not present in artificially fertilized eggs. The wild egg mass appeared to be resistant to microbial infection, unlike the incomplete and damaged egg masses spawned in captivity, suggesting that the intact egg mass protects the eggs within. Chorion expansion was also more extensive in the wild egg mass. Hatchling behaviours included proboscis extension, chromatophore activity, and a range of swimming speeds that may allow them to exercise some control over their distribution in the wild.
 

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Description of food sources used by jumbo squid Dosidicus gigas (D’Orbigny, 1835) in Ecuadorian waters during 2014
R. Rosas-Luis, L. Chompoy-Salazar 2015 (subscription)
Abstract
Jumbo squid, Dosidicus gigas, is a species endemic to the eastern Pacific. Its distribution ranges from the Gulf of Alaska to Chile. These squids are important components of the ecosystem, as they are prey to sharks, billfishes, and marine mammals, and active predators of myctophid fishes, other squids and crustaceans. In Ecuador, D. gigas is a potential resource for industrial and artisanal fisheries, but they are often by-catch in artisanal fisheries that use trammel net and gill-netting methods. Due to the importance of D. gigas as prey and predator, we performed this exploratory research to describe the specific composition of their diet and identify their most important prey. A total of 167 squids were sampled in Santa Rosa, Salinas, Ecuador from May to December 2014. Squids ranged between 17.5 and 52 cm ML, and our results showed an average size of 40 cm ML. According to the %IRI the diet was mainly composed of fish and squids. Two myctophids, Lampanyctus sp. and Myctophum sp., were important food resources. Our results showed that there is no difference between food resources, and the sex, size, and maturity of squids. Cannibalism can also occur and ranges from small to large D. gigas, and is influenced by unavailable prey in the surface waters during fishing activity.
 

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An ethogram of the Humboldt squid Dosidicus gigas Orbigny (1835) as observed from remotely operated vehicles
Lloyd A. Trueblood, Sarah Zylinski1, Bruce H. Robison, and Brad A. Seibel 2015 (subscription)

Abstract
Many cephalopods can rapidly change their external appearance to produce multiple body patterns. Body patterns are composed of various components, which can include colouration, bioluminescence, skin texture, posture, and locomotion. Shallow water benthic cephalopods are renowned for their diverse and complex body pattern repertoires, which have been attributed to the complexity of their habitat. Comparatively little is known about the body pattern repertoires of open ocean cephalopods. Here we create an ethogram of body patterns for the pelagic squid, Dosidicus gigas. We used video recordings of squid made in situ via remotely operated vehicles (ROV) to identify body pattern components and to determine the occurrence and duration of these components. We identified 29 chromatic, 15 postural and 6 locomotory components for D. gigas, a repertoire rivalling nearshore cephalopods for diversity. We discuss the possible functional roles of the recorded body patterns in the behavioural ecology of this open ocean species.
 

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Reproductive strategy in jumbo squid Dosidicus gigas(D’Orbigny, 1835): A new perspective
Alejandro Tomás Hernández-Muñoz,Carmen Rodríguez-Jaramillo, Arminda Mejía-Rebollo, César Augusto Salinas-Zavala 2015 (subscription)

Abstract
The jumbo squid Dosidicus gigas has been considered to be semelparous by several authors. However, to date no studies to support this assumption have been conducted. The present work tests the hypothesis that female jumbo squid do not die after a single reproductive event and provides evidence of the presence of postovulatory follicles (Pof) in females of different sizes. They indicates previous spawning in females in which they are present.

Histological analysis was performed on reproductive structures of 73 female jumbo squid from the northwest of Mexico using hematoxylin-eosin staining. Using image analysis five ovarian stages were identified: (I) previtellogenesis, (II) vitellogenesis, (III) postvitellogenesis, (IV) spawning (in which 3.73% show atresia and the presence of Pof) and (V) Postspawning, in which a higher proportion (4.86%) show atresia and Pof. It is already known that the jumbo squid has asynchronic ovarian development with partial spawning during the reproductive period. However, the consistent presence of postovulatory follicles and the presence of oocytes of different sizes and development support the hypothesis that the jumbo squid is a multiple spawner with more than one reproductive event during its life cycle.
 

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Paralarvae of the complex Sthenoteuthis oualaniensis-Dosidicus gigas (Cephalopoda: Ommastrephidae) in the northern limit of the shallow oxygen minimum zone of the Eastern Tropical Pacific Ocean (April 2012) (subscription)

Abstract
The three-dimensional distribution of the paralarvae of the complex Sthenoteuthis oualaniensis - Dosidicus gigas (Cephalopoda: Ommastrephidae) was analyzed at the northern limit of the shallow oxygen minimum zone in the Eastern Tropical Pacific in April, 2012. The hypoxic water (∼ 44 μmol/kg or 1 mL/L) rises from ∼ 100 m depth in the entrance of the Gulf of California to ∼ 20 m depth off Cabo Corrientes. Most of the paralarvae of this complex, dominated by D. gigas, were concentrated in the Gulf entrance, between the thermocline (∼20 to ∼ 50 m depth) and the sea surface, in the warmest (> 19°C) oxygenated (> 176 μmol/kg) layer. The highest abundance of paralarvae was detected in an anticyclonic eddy (∼120 km diameter and > 500 m deep), which contained lower salinity water (< 35 g/kg), consistent with formation in the California Current. Lower paralarvae abundance was recorded further south off Cabo Corrientes, where hypoxic layers were elevated as water shoaled near shore. Almost no paralarvae were found in the north of the study area beyond the strong salinity front (∼ 34.8 - 35.4 g/kg) that bounded the anticyclone. These results showed an affinity of the paralarvae for lower salinity, oxygenated water, illustrated by the influence of the mesoscale anticyclonic eddy and the salinity front in their distribution. Based on this study, it can be concluded that the expansion of the depth range of hypoxic water observed in the Eastern Tropical Pacific may be increasing environmental stress on the paralarvae by vertically restricting their habitat, and so affecting their survival. This article is protected by copyright. All rights reserved.
 

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POPULATION DYNAMICS OF JUMBO SQUID DOSIDICUS GIGAS IN PACIFIC ECUADORIAN WATERS
ENRIQUE MORALES-BOJORQUEZ, JOSE LUIS PACHECO-BEDOYA 2016 (PDF Journal of Shellfish Research, Vol. 35, No. 1, 1–14)

ABSTRACT Population dynamic studies of Dosidicus gigas have not been reported in Ecuadorian waters. The number of cohorts in the population and reproductive features such as sex ratio, seasonal changes in maturity stages, and size at first maturity are unknown. This knowledge is crucial in the study area, because it can provide fishery management support to Ecuadorian stakeholders. Biological data from 2013 (March–December) and 2014 (January–December) in Ecuadorian waters were analyzed. Biological sampling per month was carried out during every year in different coastal waters off of Ecuador. The biological findings indicated the presence of three size groups in the Ecuadorian squid stock, which estimated to be individuals less than 50 cm mantle length (ML). The monthly size groups changed between one and three size groups in 2013 and 2014. The ML at first maturity for females of jumbo squid estimated in 2013 was L50% ¼ 32.4 cm ML, and L50% ¼ 35.5 cm ML in 2014. For both fishing seasons, the ML–mantle weight relationship estimated for jumbo squid presented isometric growth, and the sex ratio for D. gigas showed that females were more abundant than males. This study found that the ML structure of jumbo squid, the number of size groups, and ML at first maturity are different from that previously estimated in traditional fishing areas of D. gigas in the eastern Pacific Ocean.
 

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Characterization of the northernmost spawning habitat of Dosidicus gigaswith implications for its northwards range extension
Jorge E. Ramos, Alejandro Ramos-Rodríguez, Gastón Bazzino Ferreri, J. Alejandro Kurczyn, David Rivas, César A. Salinas-Zavala 2017 (subscription Marine Ecology)

ABSTRACT: The jumbo squid Dosidicus gigas is an ecologically and commercially important species whose northernmost geographic limit is the Gulf of California. However, over the last decades this species has extended its geographic distribution polewards, with associated impacts on the ecosystem. The origin of range-shifting individuals is poorly understood; therefore, we aimed to identify and characterize the northernmost spawning habitat of this species. Implications of the location and oceanographic conditions of the spawning habitats, migration capacity and life history characteristics of D. gigas are also discussed to elucidate its migration pattern. The northernmost spawning area was located between the biological activity centres (BACs) around the Gulf of Ulloa at the west coast of southern Baja California Peninsula during winter, summer and autumn 2005. Generalized linear models indicated that the interaction of sea surface salinity and thermocline depth, and the effect of latitude and sea surface temperature explained most of the variability in paralarval presence, whereas chlorophyll a and latitude explained paralarval abundance. Simulations indicated that paralarvae were dispersed towards the southwest or temporarily remained between BACs. The northwards incursion of D. gigas may be favoured by BACs and upwelling events along the coast of the northeastern Pacific. In warm years, D. gigas is likely to spawn off the Baja California Peninsula, it may actively migrate as far north as Alaska (USA) tracking BACs and upwelling conditions in search of feeding grounds, and it may return from different areas along the northeastern Pacific to spawn off the Baja California Peninsula.
 

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