Latitudinal changes of euphausiid assemblages related to the morphological variability of the sound scattering layer along Baja California, October 1994

Hydroacoustical evidence of autumn inshore residence of the pelagic red crab Pleuroncodes planipes at Punta Eugenia, Baja California, Mexico

“…The target strength of the red crab ranged between -50 and -54 dB. The largest aggregations were found in Bahía Magdalena during summer (June 1995 and1996;24 to 25°N) and nearshore at Punta Eugenia (27 to 28°N) during autumn and spring (March 1995and 1996, October 1994. These observations suggest that the conceptual model of inshoreoffshore adult population migration is valid for Bahía Magdalena, but apparently not for Punta Eugenia at least during autumn.…”

“…However, huge benthic-pelagic concentrations of this crustacean occur nearshore during autumn at Punta Eugenia (27 to 29°N). Circadian cycles of the spatial distribution of these aggregations were recorded with a single beam echosounder Simrad along Baja California during October 1994, March, June, and October 1995, and March and June 1996. Data obtained from Isaacs-Kidd midwater net trawls during October 1994 along Baja California were used to identify the red crab aggregations using hydroacoustics.…”

Heterophryxus Appendiculatus G. O. Sars, 1885 (Isopoda, Dajidae): Extension of its Known Range in the Northeast Pacific and Caribbean Sea (Mexico) that Indicates Inter-Ocean Zoogeographic Distribution

“…It is likely that H. appendiculatus also infests other species of krill in the newly reported localities. We recorded a single unattached female on the southwest coast of the Baja California Peninsula, where Euphausia eximia Hansen, 1911 (50.1%), Nyctiphanes simplex (40.6%), and Euphausia tenera Hansen, 1905 (4.5%) together account for about 95% of local euphausiid total abundance (Gómez-Gutiérrez et al, 1999). Similarly, Draco & Albertelli (1975) reported a large number of free-swimming H. appendiculatus (n = 57) in the Mediterranean Sea, at stations with a dominant abundance of E. krohnii and Meganyctiphanes norvegica (M. Sars, 1857).…”

“…Zooplankton samples were collected during two oceanographic cruises carried out in Mexican waters: (1) along the west coast of the Baja California Peninsula during 17-30 October 1994(Gómez-Gutiérrez et al, 1999 and (2) Tattersall (1905Tattersall ( , 1913 North Atlantic (Gulf of Biscaya) Not reported, likely free-swimming Stephensen (1915) North Atlantic The isopods found to be Heterophyxus appendiculatus were identified from all descriptions currently available for this species (Sars, 1865;Sebastian, 1970;Drago & Albertelli, 1975;Shimomura & Ohtsuka, 2008). H. appendiculatus specimens collected in the western Caribbean Sea are deposited in the zooplankton collection of El Colegio de la Frontera Sur (ECO-CH-Z 04094, 04095, and 06588).…”

Early study on vertical distribution of zooplankton biovolume in Bahia Magdalena, Baja California Sur, Mexico.

“…Los ni ve les de abun dan cia del zo o plancton ob te ni dos en el es tra to de 10 m -20 m coin ci den con lo en con tra do, me dian te re gistros só ni cos, en otras zo nas cos te ras de la pe nín su la de Ba ja Ca li for nia en me ses de otoño-in vier no (Gó mez-Gu tié rrez & Ro bin son, 1997;Gó mez-Gu tié rrez et al, 1999), lo que su gie re que la co mu ni dad es ta ría pre fe ren te -…”