Octopus Hubbsorum Research Articles

Ovarian and testicular ripening process, reproductive season and size at maturity in Octopus hubbsorum (Cephalopoda: Octopodidae)

ABSTRACT This paper contributes to the knowledge of the reproductive biology of Octopus hubbsorum Berry 1953. Its reproductive season in Bahía Magdalena, Baja California Sur ranges from May to October. The increase of gonadosomatic index in females coupled with the decline in Guerra’s index and the increase in oocyte diameter in May and September were indicative of spawning. The total sex ratio was 1:1; males were larger than females. Females reach sexual maturity at 119.7 mm of dorsal mantle length and 628.6 g of total weight. This paper also addressed different aspects on reproductive studies, allowing the identification of the type of gonadal development as a group-synchronous type and the transition from physiological to functional maturity, in both qualitative and quantitative terms (proportion of oocyte stages). Detailed descriptions of the oogenesis/folliculogenesis stages of O. hubbsorum are presented with detailed photographs (in Supplemental online material).

Histological and Morphological Characterization of the Development of the Kölliker's Organs of Green Octopus Octopus hubbsorum

Histological and Morphological Characterization of the Development of the Kölliker's Organs of Green Octopus Octopus hubbsorum

Geographic differences in the diet and isotopic niche of Octopus hubbsorum (Cephalopoda: Octopodidae) in the Mexican Pacific

ABSTRACT Octopus hubbsorum is an important fisheries resource in the Mexican Pacific and a link among different trophic levels due to its ecological role as both predator and prey. In this study, the spatial variations in the diet, isotopic niche and trophic position of O. hubbsorum were determined by analysing digestive contents along with carbon and nitrogen stable isotopes. Octopuses were sampled from four locations, three in the Gulf of California ecoregion and one in the Mexican Pacific transition ecoregion. The diet of O. hubbsorum consisted of 11 major taxonomic groups. Crustaceans were the most important prey, although some individuals consumed high proportions of polychaetes, eggs and cephalopods. The stable isotope values showed high variation (−15.86 to −13.76‰ δ13C; 14.80–17.23‰ δ15N), reflecting signals of the base of the food web at the four locations. Differences in trophic positions and isotopic niches confirm the role of this species as a generalist predator, as it can shift among alternate food sources according to local availability. Overall, our results suggest that O. hubbsorum has a similar ecological role at all locations as a predator of crustaceans and, to a lesser extent, of molluscs and fish.

Description of the spawning, embryonic development, and paralarvae of the green octopus Octopus hubbsorum Berry 1953 (Cephalopoda: Octopodidae) under laboratory conditions

Description of the spawning, embryonic development, and paralarvae of the green octopus Octopus hubbsorum Berry 1953 (Cephalopoda: Octopodidae) under laboratory conditions

Diet of the stone scorpionfish (Scorpaena mystes) from the coastal region of Santa Rosalia, Gulf of California, Mexico using stomach contents and stable isotope analyses

In Santa Rosalia, stone scorpionfish, Scorpaena mystes, is an important part of the benthic community, hence its ecology regarding food habits by means of stomach contents and isotope signal were studied. Stone scorpionfish were captured during an annual cycle, from May 2015 through April 2016 in waters off Santa Rosalia, Baja California Sur, Mexico. Stomach contents and muscle samples were analyzed for δ13C and δ15N isotopic signature in order to describe the trophic niche of the stone scorpionfish both in terms of the prey items consumed and the assimilated items. The diet comprised 22 items: cephalopods, bivalves, crustaceans, seaweeds, and unidentified organic matter (UOM). The most important preys according to the %IRI (Index of Relative Importance) were the cephalopod Octopus hubbsorum (19.5%), non-identified crustaceans (18.8%), brachyuran crabs (15.9%), Serranus psittacinus (9.3%), Dosidicus gigas (8.8%) and Cronius ruber (7.3%). No significant differences were found between the diet of females and males, sizes or seasons. The mean of the δ15N was 19.07 ± 0.63‰ and for the δ13C was of −14.76 ± 0.81. The main contributors to the diet, according to the Stable Isotope Mixing Model in R (SIMMR), were the cephalopod Octopus hubbsorum with a mean contribution of 32% followed by demersal fishes with 31%. No significant differences were found between the sexes, sizes or seasons, or in the isotopic niche. The Amundsen plot shows that the stone scorpion fish is a generalist predator, while the trophic level was 4.3 with stomach contents and 4.0 by means of the isotopic signature. This is the first study of stone scorpionfish involving its trophic niche.

Trophic ecology of the Hubb's octopus Octopus hubbsorum (Cephalopoda: Octopodidae) in the central Mexican Pacific

ABSTRACT The diet of the Hubb's octopus Octopus hubbsorum along the coast of Acapulco, Guerrero, Mexico, was determined by analysing the stomach contents of 413 individuals collected monthly between February 2017 and March 2018. Most stomachs (74.3%) presented contents, while 25.7% were empty. Sixty prey items were identified and grouped into 16 categories. The most frequent prey items were Petrolisthes sanfelipensis, Clastotoechus diffractus, Petrolisthes hians and Alpheus spp. Smith's index indicated that O. hubbsorum follows a generalist diet for each hydroclimatic season, sex and size class (1: juvenile; 2: young adult; 3: mature adult). Cannibalism was frequent among males, less so among females. Pianka's index revealed a higher overlap among the three size classes of both sexes during the dry season, while during the rainy season the overlap was reduced for size classes 2 and 3 in both sexes. The average isotopic values overall were δ13C −14.96‰ (±0.08) and δ15N 13.02‰ (±0.09). A significant difference (P = 0.005) was observed in δ13C among hydroclimatic seasons (rainy and dry) and size classes, while for δ15N a significant difference (P = 0.013) was observed between seasons. Stomach content analysis gave values of the trophic position of O. hubbsorum ranging from 3.57 to 3.72, whereas the values obtained using stable isotope analysis, using δ15N, ranged from 3.52 to 3.86. Variation was observed in isotopic niche size and Layman's metrics among hydroclimatic seasons. A higher isotopic niche overlap was observed between size classes 2 and 3 during the dry season. The rocky shore ecosystem has been heavily exploited by artisanal fisheries (fish and invertebrates). A more integrated, ecosystem-based management of these fisheries requires an understanding of their trophic structure.

New microsatellite loci for estimating genetic diversity and structure in Octopus hubbsorum from Nayarit, México.

Octopus hubbsorum Berry, 1953 is the most important species for commercial fishing in the Mexican Pacific. However, there is a lack of information regarding population structure that could have important management implications. We tested 44 microsatellite loci in O. hubbsorum by cross-amplification from O. bimaculatus. Genetic diversity and structure was tested over 30 octopus sampled from Santa Cruz de Miramar (Nayarit, México). A total of 11 loci were successfully amplified. All loci were polymorphic with the number of effective alleles ranging from 2.13 to 23.14, while three loci significantly deviated from Hardy-Weinberg equilibrium. No significant LD was observed between pairs of loci (P ≥ 0.05). The application of the new markers in a O. hubbsorum population from Santa Cruz de Miramar Nayarit, México, didnot showed Wahlund or isolate breaking effects due to the mixing of distinct populations. The loci were useful to estimate levels of pairwise relatedness and to discard the presence of recent demographic bottlenecks in the population. We consider that eight microsatellites are adequate from the 11 amplified loci.

Diversity and population genetic structure of Octopus hubbsorum in the Mexican Pacific inferred from mitochondrial DNA sequences

Octopus hubbsorum is the most commonly captured species of octopus on the western coast of Mexico. Despite the commercial importance of this species, management information remains scarce. We determined the genetic diversity and population genetic structure of O. hubbsorum by using mtDNA sequences (COI and ND5). The population structure was not supported by AMOVA or a spatial clustering model. Furthermore, an isolation by distance model did not explain our data. Three haplogroups were detected using a Bayesian assignment; however, the distribution of these haplogroups did not differ among the sampling sites. Our results indicated historical processes of a sudden population expansion, as has been reported for other species in the study region as consequence of climatic changes. However, this expansion did not affect the distribution of the mitochondrial lineages analysed in the study. The weak population genetic structure in O. hubbsorum associated with the life history of the species can explain our results. We suggest that to expand knowledge regarding the genetic structure and population dynamics of O. hubbsorum throughout its range, markers such as microsatellites or single-nucleotide polymorphisms (SNPs) are needed. Thus, on the basis of the information available, the studied population should be assumed to have a weak genetic structure.

Double Hectocotylization in Hubb's Octopus, Octopus hubbsorum (Cephalopoda: Octopodidae)

Double hectocotylization in octopods has only been reported for some individuals of a few species, often affecting arms of the same pair. We herein report several cases of non-bilateral double hectocotylization in a single species collected in different locations of the Mexican Pacific coast. The octopuses were identified by morphological and molecular criteria as Hubb's octopus, Octopus hubbsorum. The “regular” and “accessory” hectocotyli were examined by histological analysis; in the latter, the calamus was present and no ligula was detected. Double hectocotylization can be an intrinsic character of the species.

Is There a Risk to Humans from Consuming Octopus Species from Sites with High Environmental Levels of Metals?

Although octopuses are in high-demand globally and can bioaccumulate high concentrations of metals, the risk associated to its consumption is poorly understood. We compiled literature data from eight locations in Europe, North America and Northern Africa with different environmental levels of metals to evaluate: (1) the risk to human health through consumption of muscle tissues and digestive glands of Octopus hubbsorum, O. vulgaris and Eledone cirrhosa, and (2) the maximum allowable consumption rates (CRlim). The assessments were done according the United States Environmental Protection Agency. The results indicate the absence of health risk through consumption of muscle tissues, and high health risk through consumption of digestive glands (attributed to its high Cd levels), reflected in its 1ow CRlim values. In conclusion, even in contaminated sites the consumption of octopus muscle tissues is not an issue of concern, while the consumption of digestive glands should be more carefully monitored to avoid health problems.

Diet ofOctopus hubbsorum(Cephalopoda: Octopodidae) from the Coast of Oaxaca, México

In this study, trophic ecology of Octopus hubbsorum (Berry, 1953) was examined in relation to the species life cycle and dry and rainy seasons. A total of 184 individuals were obtained from the commercial artisanal catches at different localities along the coast of Oaxaca, Mexican tropical Pacific, from January 2011 to December 2012. Analysis of digestive tract contents revealed that O. hubbsorum preyed upon 43 different prey species belonging to five zoological groups (Crustacean, Mollusca, Teleostei, Echinodermata and Polychaeta), cannibalism was only occasional. The most important prey was the porcelain crabs genus Petrolisthes, contributing 52.1% and 37.8% to the total Index of Relative Importance, in females and males, respectively. Dietary comparison between different maturity stages revealed significant changes in the diet with maturation. The proportion of empty stomachs observed between the dry (18.75 %) and rainy (12.5 %) seasons did not differ significantly (χ2 = 0.55, P > 0.05). Our results suggest that females likely migrate to shallow areas to feed in preparation for mating, they may do this to increase energy intake prior to egg caring and incubation, a period when they do not feed. The high productivity waters along the coast of Oaxaca seem to be important to the survival of this species because they offer key food resources at a critical reproductive stage.

Bioaccumulation and biomagnification of potentially toxic elements in the octopus Octopus hubbsorum from the Gulf of California

The concentrations of 21 potentially toxic elements (PTEs) were determined in the tissues of Octopus hubbsorum from three locations along the Gulf of California coast: two near Santa Rosalia (SR), a site with historical metal contamination, and one in La Paz Bay, a reference site. Concentrations of Cd, Co, Cr, Mn, Ni, Pb, and Zn in octopus from the two SR sites were higher than those from the reference site, reflecting the higher sediment concentrations at the mining-impacted locations. The highest bioaccumulation and biomagnification of elements was found in digestive gland and branchial hearts, while the lowest was observed in the mantle, where the mean concentration of PTEs did not exceed international standards for human consumption of octopus. This study found elevated PTEs in octopus from sites with high metal contamination, and presents the first data on these elements in octopus from the Gulf of California.

Iron Profile of Octopus Hubbsorum (Cephalopoda: Octopodidae) for Enrichment of the Mexican Diet

Iron Profile of Octopus Hubbsorum (Cephalopoda: Octopodidae) for Enrichment of the Mexican Diet

Sexual Differentiation ofOctopus hubbsorum(Mollusca: Cephalopoda) Using Body Dimensions and the Shape and Size of the Stylets: A Traditional and Geometric Morphometric Analysis

Sexual differences in size and morphology are conspicuous features of dioecious organisms like octopuses. In this study, we analyze differences on body dimensions and the size and shape of Octopus hubbsorum Berry, 1953 stylets, using traditional and geometric morphometrics to ascertain if both methods can recognize differences between males and females. Traditional morphometrics revealed differences in body and stylet sizes because the females were bigger than the males, and the total body weight was the most related body measure with all the stylets measures. Due to the shape of the stylets we used two landmarks and 40 semilandmarks, and for the semilandmarks alignment we used two methods: minimization of bending energy (min BE) and minimization of Procrustes distance (min D), to test if the method to align semilandmarks influenced the analysis. Differences were found between the two methods, such as the mean shape, the percentage of predicted organisms to their corresponding sex in discriminant function analysis (DFA), and the relationships between stylet shape and body size as well as centroid size of the stylets; however, the deformation grids were similar between the two methods and their canonical variate analysis (CVA) found significant differences in mean shape of the stylets of males and females. These results demonstrated the morphometric sexual dimorphism in O. hubbsorum using body dimensions and the size and shape of the stylets.

Reproductive Biology ofOctopus hubbsorum(Cephalopoda: Octopodidae) from the Coast of Oaxaca, Mexico

Abstract: Aspects of the reproductive biology of Octopus hubbsorum Berry, 1953 from the Coast of Oaxaca, Mexico, were analyzed. A total of 998 specimens of mantle length (ML) ranging from 40–220 mm were obtained from catches of artisanal fisheries from January 2011 to December 2012. The reproductive activity was assessed using gonad histology, oocyte development, maximum oocyte size, maturity, and gonadosomatic index. A good correspondence between main macroscopic characteristics and histological structure was observed, as emphasized in females where oviductal gland morphology correlates very well in the macroscopic evaluation of maturity. The fecundity range was estimated between 22,447–545,444 oocytes. Maturing oocyte size—frequency distribution was polymodal, and the spawning season is extended with two reproductive peaks. These results indicate that O. hubbsorum has asynchronic ovulation and, is an intermittent terminal spawner. The estimated size at sexual maturity (L50) for females was 90.5 mm ML an...

Arm Abnormality inOctopus hubbsorum(Mollusca: Cephalopoda: Octopodidae)

Octopus hubbsorum Berry, 1953 occurs in a wide region of the oriental tropical Pacific. This is the principal target species in the octopus fisheries in Mexico. A female with abnormally bifurcated second arm was collected from an artisanal fishery in Puerto Angel, Oaxaca, Mexico.

Close Genetic Relationships between Two American Octopuses:Octopus hubbsorumBerry, 1953, andOctopus mimusGould, 1852

The octopuses Octopus hubbsorum and Octopus mimus are two species of octopuses that inhabit shallow waters of the eastern Pacific Ocean. The former species is found in the north, from the Gulf of California to Oaxaca, Mexico, whereas O. mimus lives in the south, from Peru to Chile. To infer the phylogenetic relationships between these species we used the mitochondrial genes cytochrome oxidase subunits I and III, and r16S with the aim of comparing their genetic distances with those of other Octopus sp. The genetic distance values between both species estimated per gene or concatenated were low (0%–1.6%) in comparison with other interspecific distances values (4.6%–18.4%). Application of 10× rule showed there is no overlap between intra- and interspecific octopus distances, whereas the application of the 4× rule confirmed that both octopuses belong to the same lineage. The resolved topologies with maximum parsimony and Bayesian approaches clustered the specimens of O. hubbsorum and O. mimus in a single clade with high bootstrap and posterior probability values (100 and 1.0, respectively). These results allow us to suggest that O. hubbsorum and O. mimus could represent the same species.

First Description of Eggs and Paralarvae of Green OctopusOctopus hubbsorum(Cephalopoda: Octopodidae) under Laboratory Conditions

Abstract: Octopus hubbsorum Berry 1953 occurs in a wide region of the tropical eastern Pacific. It is the principal target species in the octopus fisheries, but no information is available with regard to embryonic and larval development. The objective of this study was to describe O. hubbsorum eggs, embryos, and paralarvae under laboratory conditions. One O. hubbsorum female with egg clutch was collected (15°39′N, 96°31′W) on 26 October 2012. Embryonic development lasted from 20 to 30 days. The newly hatched paralarvae are planktonic; morphologically, this feature is expressed by a relatively small arm-length, 3 suckers per arm, and mean mantle length of 1.27 ± 0.14 mm. This article provides a detailed survey of O. hubbsorum, embryogenesis from organogenesis through hatching under laboratory conditions; including detailed descriptions of externally visible morphological features that are easily distinguished in either live or freshly fixed organisms under a dissecting microscope.

Characterization of microsatellite loci from two-spotted octopus Octopus bimaculatus Verrill 1883 from pyrosequencing reads

We characterized 22 novel microsatellite loci in the two-spotted octopus Octopus bimaculatus using 454 pyrosequencing reads. All loci were polymorphic and will be used in studies of marine connectivity aimed at increasing sustainability of the resource. The mean number alleles per locus was 13.09 (range 7–19) and observed heterozygosities ranged from 0.50 to 1.00. Four loci pairs were linked and three deviated from Hardy–Weinberg equilibrium. Eighteen and 12 loci were polymorphic in Octopus bimaculoides and Octopus hubbsorum, respectively.

Reproducción, dieta y pesquería del pulpo <i>Octopus (Octopus) hubbsorum</i> (Mollusca: Cephalopoda) en la costa de Oaxaca, México

The octopus Octopus hubbsorum (Berry 1953) ranges widely and is important for the artisanal fishery in Puerto Angel, Oaxaca, Mexico. Samples were taken approximately at every two weeks from January 2002 to November 2003. All organisms were measured for dorsal mantle length (DLM) and total weight; sex and maturity gonadic stage were registered. For the stomach content analysis, frequency of occurrence and emptying indexes were used. The 352 organisms caught ranged from 4 to 18 cm in DLM; the sex ratio was different from 1 (chi2 = 24.2, p<0.05) throughout the year. The maximum values of the GSI appeared in May (4.1917 for females; 1.2675 in males). LDM for first sexual maturity (LDM50%) was 16 cm (females) and 14 cm (males). Octopus hubbsorum moves from deep waters to the coast, probably in search of better conditions, and lays masses of eggs on rocky substrata. They are fished from March to October, with higher intensity in April and May. Fishing effort was related to the oceanographic characteristics and the atmospheric conditions of the area. From April to September the CPUE monthly mean was 20-10 kg/divers/day. Using the CPUE and environmental condition relationship, the estimated adequate superficial temperature for fishing is 29.5 degrees C.