Marine flora and fauna of the eastern United States Mollusca: Cephalopoda

The cephalopods found in neritic waters of the northeastern United States include myopsid and oegopsid squids, sepiolid squids, and octopods. A key with diagnostic illustrations is provided to aid in identification of the eleven species common in the neritic waters between Cape Hatteras and Nova Scotia; included also is information on two oceanic species that occur over the continental shelf in this area and that can be confused with similar-looking neritic species. Other sections comprise a glossary of taxonomic characters used for identification of these species, an annotated systematic checklist, and checklists of the 89 other oceanic species and 18 Carolinian and subtropical neritic species that might occur occasionally off the northeastern United States. (PDF file contains 30 pages.

Cephalopods from the stomachs of sperm whales taken off California

Cephalopod remains (beaks, bodies, and parts of bodies) were collected from the stomachs of 157 sperm whales (Physeter macrocephalus) taken off central California (lat. 37°-39°N). At least 24 species representing 14 families were identified. Frequencies of occurrence of the six most numerous taxa were Moroteuthis robusta 72.0%, Gonatopsis borealis 66.2%, Histioteuthis dofleini 36.9%, Galiteuthis spp. (including G. phyllura and G. pacifica) 36.3%, Octopoteuthis deletron 35.0%, and Vampyroteuthis infernalis 27.4%. One find of two Mesonychoteuthis hamiltoni beaks strongly suggests transequatorial migration by one large male sperm whale. (PDF file contains 18 pages.

Results of bottom trawl surveys carried out in Vietnamese waters (20-200 m) in 1996-1997

Bottom trawl surveys were conducted in the southwest monsoon season in 1996 (survey 1) and in the northeast monsoon season in 1996-97 (survey 2) throughout Vietnamese waters. The surveys mainly covered the depth zone 50-200 m but in the northeast monsoon season the depth zone 20-50 m was included in the northern and southern areas. Overall, 273 trawl hauls were conducted. The total biomass for Vietnamese waters in the depth zone 20-200 m was estimated at 700 000 t . Biomass estimates are given for the most abundant species. A relatively higher mean catch-per-unit effort (CPUE) was obtained from survey 2 than from survey 1 and in partcular at depth ranges 50-100 and 100-200 m in south Vietnam. Overall, the dominant families were Monacanthidae (34%), Carangidae (15%), Trichiuridae (9%) and Synodontidae (6%)

Sampling Frame for Mediterranean and Black Sea CFP Monitoring indicators

The Mediterranean and Black Sea list of stocks to be used for computing the indicators was based on a ranking system approach for which the species having a rank in the first ten positions either in total live weight or total economic values were chosen. Landings and economic values for the Mediterranean and Black Sea (FAO area 37) provided by “2016_STECF 16-11 - EU Fleet Economic and Transversal data tables” were used. The reference years were 2012 and 2014 (the last three years available for all the GSAs) and, as geographic strata, the Geographical Sub Areas (GSAs) belonging to EU countries and for which data were available were considered. In the top ranking 10 stocks based on both in terms of live weight and economic value by GSA applied to AER Landings, many combined/nei groups categories were selected. Based on local expert knowledge it was possible split some mixed categories at species level while, it was decided to drop from the list both the misreporting species and the mixed categories for which it wasn't possible defined clearly the species composition. Eventually 230 stocks were selected.JRC.D.2-Water and Marine Resource

Cephalopod identification keys to Histioteuthidae, Cranchiidae and Octopodiformes of the Azores, with an updated check-list

This work is a combination of unpublished cephalopod identification keys compiled by Malcolm R. Clarke for the Azores region (Central North Atlantic) and a review of the Octopoda of the Azores by João Gonçalves (MSc Thesis 1993, originally written in Portuguese), updated with recent literature. A regional list of cephalopod species of the Azores is provided totaling 83 species, with identification keys for: i) Histioteuthidae, including five species; ii) Cranchiidae, including eleven species; and iii) Octopodiformes, including Vampyroteuthis infernalis Chun, 1903 (Order Vampyromorpha), three cirrate and fourteen incirrate octopuses. Separate keys are given for Octopodiformes species. The revisions are discussed and a more detailed description of Octopoda species is included.Oma – Observatório do Mar dos Açores ; MARE – Centro de Ciências do Mar e do Ambiente ; IMAR – Instituto do Mar ; DOP – Departamento de Oceanografia e Pescas ; Universidade dos Açoresinfo:eu-repo/semantics/publishedVersio

Validation of macroscopic maturity stages of the Patagonian red octopus Enteroctopus megalocyathus

Testes and ovaries of Enteroctopus megalocyathus collected along the Patagonian Atlantic coast were analysed histologically to validate the macroscopic maturity scales adopted for this species. Changes through the course of development of the seminiferous tubules and of the oocyte/follicular cell complexes were characterized and these were classified into five and six microscopic categories of development respectively. A histological maturity index, based on the frequencies of microscopic categories, was used to assess the correspondence between macroscopic maturation stages and the microscopic level of development of the gonadal tissue. Seminiferous tubules showed a regular and progressive pattern of microscopic development within each macroscopic stage and between consecutive macroscopic stages. However, a minority of males exhibiting seminiferous tubule with sperm did not display macroscopic characteristics of the mature-spawning stage. In females, an overlapping of microscopic categories was observed in maturing macroscopic stages. Previtellogenic oocytes were not present at maturespawning or spent stages. Significant changes in the histological maturity index were observed between consecutive macroscopic stages, confirming the validity of macroscopic maturity scales of both sexes. In addition, by considering both macroscopic and microscopic criteria, it was possible to determine the overall state of development and functioning of the reproductive system during sexual maturation of this species.Fil: Ortiz, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

The cephalopod prey of the Weddell seal, Leptonychotes weddellii, a biological sampler of the Antarctic marine ecosystem

Weddell seals, Leptonychotes weddellii, are important apex predators in the food web of the Antarctic marine ecosystem. However, detailed information on their trophic relationships with cephalopods is scarce. Moreover, cephalopods play a key role in the marine environment, but knowledge of their feeding habits is limited by lack of data. Here, we have combined the use of this seal as a biological sampler together with measurements of the stable isotopic signature of the beaks of their cephalopod prey. Thus, the aims of the present study were: (1) to examine in detail the cephalopod portion of the diet of Weddell seals by means of scat analysis and (2) to assess the habitat use and trophic level of the different cephalopod prey taxa identified. From January to February 2009, a total of 48 faecal droppings were collected at Hope Bay, Antarctic Peninsula. Cephalopods were mainly represented by beaks (n = 83) which were identified to the lowest possible taxonomic level. Furthermore, subsamples of beaks were separated for further isotopic analysis. Relative abundance of stable isotopes of carbon (δ13C) and nitrogen (δ15N) was determined by continuous-flow isotope-ratio mass spectrometry. Cephalopods were represented uniquely by octopods of the subfamily Eledoninae. Pareledone turqueti was the dominant prey species followed by the papillated Pareledone species group and Adelieledone polymorpha. We conclude that Weddell seals preyed primarily on benthic prey resources. Furthermore, the relatively similar δ13C and δ15N values in beaks of the three octopod prey taxa suggest that these share the same type of habitat and occupy similar trophic level positions

Rising trend in the fishery of the octopus Cistopus indicus (Orbigny, 1840) by trawlers at Mumbai

The world landings of octopus increased substantially from 35,800 t in 1950 to 3,17,200 t in 2001 (Jereb et al., 2005). Major species of octopus that contribute to the world fishery come under the genera Octopus, Cistopus and Eledone. As many as 200 species of Octopodidae are known to occur in the world Oceans (Worms, 1983) of which about 60 are reported from the Indian Ocean (Roper et al., 1984)

Species composition and distribution patterns of early life stages of cephalopods at Great Meteor Seamount (subtropical NE Atlantic)

The distribution of early life stages of cephalopods was studied during a cruise of RV Meteor in September 1998 at Great Meteor Seamount, an isolated flat-topped seamount in the subtropical eastern North Atlantic. Zooplankton sampling was conducted with a multi-opening-closing net (modified MOCNESS, 1 m² net opening, 335 µm mesh size) in seven depth strata between 290 m depth and the surface. 1180 early life stages of cephalopods were collected, representing at least 18 families and 31 mainly oceanic species. Most of the identified cephalopods comprised mesopelagic species (e. g., representatives of the families Enoploteuthidae and Pyroteuthidae) that showed diel vertical migration patterns. Hydrographic measurements parallel to zooplankton sampling revealed slow anticyclonic recirculation around the seamount forming a Taylor column and, thus, some retention potential for passive particles. Nevertheless, multivariate statistical analysis revealed no differences in the cephalopod community between the area in the proximity of the summit and the adjacent oceanic region. This was partly related to the depth of the plateau (< 300 m), which resulted in only slightly enhanced primary production, as well as to the low retention potential for active vertical migrators. However, reduced numbers of cephalopods were observed over the summit in night-time sampling, indicating gap formation above the seamount

Qualitative and quantitative distribution of planktonic cephalopods in the Exclusive Economic Zone of the west coast of India

The cephalopod larvae and juveniles in plankton samples collected during the first 10 cruises of FORV Sagar Sampada off the west coast of India from February to December, 1985 have been studied for their qualitative and quantitative distribution. The samples were obtained in Bongo net operations carried out in an extensive area covering Lat. 4° to 23° N and Long. 65° to 77° E. Out of the total 258 stations sampled, cephalopods were obtained in 110 stations in varying numbers. The estimated number of cephalopods per haul ranged between 1 and 112. Of the total number of hauls in which cephalopods obtained, 51% occurred in night hauls and the rest in day hauls