Corresponding author: Michel E. Hendrickx (
Academic editor: J. Frank
The oegopsid squids
Hendrickx ME, Urbano B, Zamorano P (2015) Distribution of pelagic squids
Cephalopods are essentially divided into two natural groups: the pelagic forms that permanently swim into the water column (i.e., squids, nautilus or cuttlefishes) and the benthic species, that live on or close to the bottom (i.e., octopuses) (
Within the pelagic forms there is a general agreement to recognize two groups: 1) the
According to
The genus
Together with fishes, stomatopods and benthopelagic shrimps, species of
There have been several studies on the occurrence of paralarvae and small juveniles of cephalopods. They are known to be related to primary production in upwelling areas (
During an intensive survey of the deep-water fauna inhabiting below the Oxygen Minimum Zone (
The material on which this study is based was collected by the R/V “El Puma” of the Universidad Nacional Autónoma de México Regional Collection of Marine Invertebrates , sampling station , mantel length , Agassiz dredge , benthic sledge
Five species of small squids were collected during sampling operations. A total of 86 specimens were obtained:
All five species examined herein were collected in the central or the southern Gulf of California, or in both (Fig.
Distribution of specimens of
In this study the material was collected either during the ascending process of large gear used for sampling the benthos or with a micronecton net and a mid-water trawl (two samples only). Although the benthic samplers were not designed to catch small pelagic squids, a rather large series of specimens was collected over the study period. In spite of this, the two oegopsid species were very common in the samples obtained during the TALUD survey (
Two species of
Our records show that Oxygen Minimum Zone
Although almost 50 samples of benthic organisms were obtained from off the west coast of the Baja California Peninsula between June 2012 and June 2014, with the benthic sledge operating at similar depth as those reported herein (see material examined), not a single specimen of pelagic squid was found. There is no clear explanation for this.
As for many marine taxa with wide distribution, identification and congruence of the morphological characters need to be reinforce using molecular markers; unfortunately oegopsids do not show high representativity in molecular analysis (
Additional sampling using more appropriate gear that can be hauled at speed of at least 5–6 knots (e.g., large size mid-water trawl) would probably be more adequate and certainly provide larger series of specimens of these elusive organisms.
Ship time was provided by the Instituto de Ciencias del Mar y Limnología,