El desarrollo temprano del calamar patagónico Loligo gahi D’Orbigny,1835 en aguas peruanas (Cephalopoda: Loliginidae)

The early development of the Patagonian squid, Loligo gahi D’Orbigny,1835, was studied in the field and in the laboratory. Egg strands, spawned off San Lorenzo Island, Peru, were collected, carried to the laboratory, and incubated in a closed sea water system. Egg capsules ranged from 88 to169 mm in length, and each capsule contained between 56 and 114 fertilized eggs. Individual eggs ranged from 1,7 to 2,1 mm in length, and the mantle length of hatchlings varied from 1,9 to 2,8 mm. Development took about 20 days at a mean temperature of 19 ºC. The pattern of embryonic development is similar to that previously observed in other species of Loligo. Following hatching, paralarvaes survived for 45 days with a diet of zooplankton (copepods, mysids and polychaete larvaes).El desarrollo temprano del calamar patagónico, Loligo gahi D’Orbigny, 1835 fue estudiado en el campo y en el laboratorio. Las puestas colectadas en la Isla San Lorenzo, Perú, fueron transferidas al laboratorio, e incubadas en un sistema cerrado de agua marina. Las cápsulas midieron de 88 a 169 mm de longitud y cada cápsula contenía entre 56 y 114 huevos fertilizados. Los huevos midieron de 1,7 a 2,1 mm de longitud y la longitud del manto de los individuos eclosionados varió de 1,9 a 2,8 mm. El desarrollo de las paralarvas se logró a los 20 días, a una temperatura promedio de 19 ºC. El patrón de desarrollo embrionario es similar al observado en otras especies de Loligo. Las paralarvas sobrevivieron 45 días con una dieta de zooplancton (copepódos, micidáceos y larvas de poliquetos)

New records of teratology in Chiton cumingsii and Chiton granosus (Mollusca: Polyplacophora) from the Peruvian coast

This paper presents the first teratological records for Peruvian waters of Chiton cumingsii Frembly, 1827 and Chiton granosus Frembly, 1827, both species very common in the Southeast Pacific. We found five abnormal individuals in C. cumingsii, and two in C. granosus, including the first recorded splitting abnormalities for these species. An individual of C. cumingsii with a new insertion plate in the tail valve was also observed. We observed that splitting abnormalities in Polyplacophora can be classified as perfect or imperfect, depending on whether the splitted valves are clearly recognized as individual fragments or not. Coalescence between the splitted valves seems to be a common phenomenon, and this coalescence can be homogeneous or heterogeneous. As both species show a combination of hypomerism, coalescence and splitting, we suggest that they are probably interrelated and represent an attempt of the developmental mechanisms of chitons to overcome a valve malformation

New records of marine bivalves from Peru

Seis especies de Bivalvia: Adrana sowerbyana (Orbigny, 1845); Malletia goniura Dall, 1890; Mytilus strigatus Hanley, 1843; Leiosolenus spatiosa (Carpenter, 1857); Pinna rugosa G.B. Sowerby I, 1835 y Delectopecten zacae (Hertlein, 1935) se reportan por primera vez para aguas peruanas. Se da información sobre la distribución, el hábitat y comentarios relevantes de cada una de las especies.The following species of Bivalvia have been recorded for the first time for Peruavian waters: Adrana sowerbyana (Orbigny, 1845); Malletia goniura Dall, 1890; Mytilus strigatus Hanley, 1843; Leiosolenus spatiosa (Carpenter, 1857); Pinna rugosa G.B. Sowerby I, 1835 and Delectopecten zacae (Hertlein, 1935). Information on the distribution geographical and same relations ecological is presented

La familia Ocythoidae (Cephalopoda: Octopoda) en el Perú

The family Ocythoidae on the basis of literature and Peruvian material is reviewed. This family has a single genus and species, Ocythoe tuberculata Rafinesque, 1814. It is an epipelagic species and possibly cosmopolitan in warm oceanic waters (subtropical) of the Atlantic, Pacific and Indico Oceans and Mediterranean Sea. Information on the systematics and Biology of the species is presented.Se revisa la familia Ocythoidae en base a la literatura y material peruano. La familia presenta sólo un género y una especie, Ocythoe tuberculata Rafinesque, 1814. Esta especie es epipelágica y posiblemente cosmopolita en aguas oceánicas cálidas (subtropicales) de los Océanos Atlántico, Pacífico e índico y del Mar Mediterráneo. Se presenta información sobre la sistemática y biología de la especie

Nuevos registros de protobranchia (Mollusca: Bivalvia) para el mar peruano

The following species of Bivalvia have been recorded for the first time for Peruvian waters: Nucula (Nucula) iphigenia (Dall, 1908); Ennucula cardara (Dall, 1916); Nuculana (Nuculana) extenuata (Dall, 1897); Orthoyoldia panamensis (Dall, 1908). These bivalves were collected in the platform and continental slope down to depths of 864 meters.Se registra por primer vez en aguas peruanas las siguientes especies de Bivalvia: Nucula (Nucula) iphigenia (Dall, 1908); Ennucula cardara (Dall, 1916); Nuculana (Nuculana) extenuata (Dall, 1897); Orthoyoldia panamensis (Dall, 1908). Estos bivalvos fueron colectados en la plataforma y talud continental hasta profundidades de 864 metros

Primer registro del pulpo ‘Octopus’ selene Voss, 1971 (Cephalopoda: Octopoda) en aguas peruanas con comentarios de su distribución geográfica

In this paper, ‘Octopus’ selene is first registered in Peruvian waters and its distribution range extends south to Cabo Blanco, Piura, Peru. Four male specimens of 34 – 50 mm ML were captured between 03°34'S and 04°06'S at depths of 109 – 150 m. A brief description is provided, with taxonomic observations and comments on its geographical distribution of this species.En el presente trabajo se registra de primera vez ‘Octopus’ selene en aguas peruanas y se amplía su rango de distribución sur hasta Cabo Blanco, Piura, Perú. Cuatro ejemplares machos de 34 – 50 mm LM fueron capturados entre los 03°34’S y 04°06’S a profundidades de 109 a 150 m. Se proporciona una breve descripción, con observaciones taxonómicas y comentarios sobre su distribución geográfica de esta especie

Nuevos registros de gasterópodos para el litoral peruano

Five species of marine gastropods are reported for the first time from Peru: Crepidula nivea Lamarck, 1799, Neosimnia aequalis (Sowerby, 1832), Simnialena rufa (Sowerby, 1832), Nitidiscala elenense (Sowerby, 1844) and Trigonostoma (Ventrilia) bullatum (Sowerby, 1832). Data on habitat and geographical distribution of any one of the species reported is included.Se reportan por primera vez para el Perú, cinco especies de gasterópodos marinos: Crepidula nivea Lamarck, 1799, Neosimnia aequalis (Sowerby, 1832), Simnialena rufa (Sowerby, 1832), Nitidiscala elenense (Sowerby, 1844) y Trigonostoma (Ventrilia) bullatum (Sowerby, 1832). Se incluyen datos sobre la distribución geográfica y el hábitat de cada una de las especies

The family Calyptraeidae in Peru (Gastropoda: Caenogastropoda)

En el presente trabajo se realiza una revisión taxonómica de la familia Calyptraeidae Lamarck, 1809, en la costa Peruana. Se confirma la presencia de 17 especies de las 19 reportadas por diversos autores. Crepidula arenata (Broderip, 1834) es sinónimo de C. excavata (Broderip, 1834). Se da información sobre la distribución geográfica y algunas relaciones ecológicas.In the present work the taxonomic of the family Calyptraeidae Lamarck, 1809 in the Peruvian coast are reviewed. The presence of 17 species of the 19 is confirmed reported by diverse authors. Crepidula arenata (Broderip, 1834) is synonymous of C. excavata (Broderip, 1834). Information on the distribution geographical and same relations ecological is presented

El género Donax en la costa peruana (Bivalvia: Telllnoidea)

In the present paper the species of Donax Linnaeus, 1758 in Peru are reviewed. The presence of 7 out of the 11 species is confirmed: D. asper Hanley. 1845; D. caelatus rothi Coan, 1983; D. obesulus Reeve, 1854; D. carinatus Hanley, 1843; D. transversus Sowerby 1,1825; D. californicus Conrad, 1837 and D. marincovichi Coan, 1983; in addition, one is recorded for the first time (D. punctatostriatus Hanley, 1843) in Peruvian waters. Information on the distribution geographical and some ecological relations is presented.En el presente trabajo se revisan las especies del género Donax Linnaeus, 1758 en el Perú. Se confirma la presencia de 7 especies de las 11 citadas: D. asper Hanley, 1845; D. caelatus rothi Coan, 1983; D. obesulus Reeve, 1854; D. carinatus Hanley, 1843; D. transversus Sowerby 1, 1825; D. californicus Conrad, 1837 y D. marincovichi Coan, 1983; y, además, se registra por primera vez a D. punctatostriatus Hanley, 1843 en aguas peruanas. Se presenta información sobre la distribución geográfica y algunas relaciones ecológicas

CMB Polarization can constrain cosmology better than CMB temperature

We demonstrate that for a cosmic variance limited experiment, CMB E polarization alone places stronger constraints on cosmological parameters than CMB temperature. For example, we show that EE can constrain parameters better than TT by up to a factor 2.8 when a multipole range of l=30-2500 is considered. We expose the physical effects at play behind this remarkable result and study how it depends on the multipole range included in the analysis. In most relevant cases, TE or EE surpass the TT based cosmological constraints. This result is important as the small scale astrophysical foregrounds are expected to have a much reduced impact on polarization, thus opening the possibility of building cleaner and more stringent constraints of the LCDM model. This is relevant specially for proposed future CMB satellite missions, such as CORE or PRISM, that are designed to be cosmic variance limited in polarization till very large multipoles. We perform the same analysis for a Planck-like experiment, and conclude that even in this case TE alone should determine the constraint on $\Omega_ch^2$ better than TT by 15%, while determining $\Omega_bh^2$, $n_s$ and $\theta$ with comparable accuracy. Finally, we explore a few classical extensions of the LCDM model and show again that CMB polarization alone provides more stringent constraints than CMB temperature in case of a cosmic variance limited experiment.Comment: 14 pages, 16 figure