Research Article |
Corresponding author: Michel Hendrickx ( michel@ola.icmyl.unam.mx ) Academic editor: Jiri Frank
© 2015 Michel Hendrickx, Brian Urbano, Pablo Zamorano.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Hendrickx ME, Urbano B, Zamorano P (2015) Distribution of pelagic squids Abraliopsis Joubin, 1896 (Enoploteuthidae) and Pterygioteuthis P. Fischer, 1896 (Pyroteuthidae) (Cephalopoda, Decapodiformes, Oegopsida) in the Mexican Pacific. ZooKeys 537: 51-64. https://doi.org/10.3897/zookeys.537.6023
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The oegopsid squids Abraliopsis and Pterygioteuthis are abundant and diverse genera with taxonomic and distributional problems. Identification and distribution of species in the Mexican Pacific has been somewhat controversial. Here are provided a large series of new records for Abraliopsis affinis, A. falco, Pterygioteuthis gemmata, P. giardi and P. hoylei from the Gulf of California and off the SW coast of Mexico. All five species were collected in the central or the southern Gulf of California, or in both. Abraliopsis affinis was found in seven samples with a total of 48 specimens, from 21°59' to 24°53'12"N. Abraliopsis falco was much less represented in the samples (14 specimens) but it was found in 10 localities, four of which correspond to the central-southern Gulf of California (north to 27°44'53"N) and six to SW Mexico (south to 16°49'18"N). In the case of Pterygioteuthis gemmata, only two records (three specimens) were obtained, both in the SW Gulf of California, while P. giardi (nine specimens) records were all from the central Gulf of California (27°44'53” to 25°39'59"N). In the case of P. hoylei (nine specimens), material was obtained in six localities, also in a restricted latitudinal range (24°23'48” to 25°56'56"N).
Mexican Pacific, squids, Abraliopsis , Pterygioteuthis , distribution, TALUD cruises
Cephalopoda is a major group of marine mollusks with almost 1000 species worldwide (
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 Myopsida squids, which contains mainly the loliginids species, and 2) the Oegopsida, a more diverse and rich group characterized by the presence of an ocular membrane (
According to
The genus Pterygioteuthis P. Fischer, 1896 (type species P. giardi, P. Fischer, 1896) contains another group of small pelagic squids with a worldwide distribution.
Together with fishes, stomatopods and benthopelagic shrimps, species of Abraliopsis (e.g., A. pacifica Tsuchiya & Okutani, 1990) are an important component of the micronecton near seamounts (
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 (OMZ), the TALUD project, specimens of small squids were collected in different sampling gear off the coast of western Mexico. This material belongs to the genera Pterygioteuthis and Abraliopsis and is reported herein.
The material on which this study is based was collected by the R/V “El Puma” of the Universidad Nacional Autónoma de México (UNAM), between 1991 and 2014. Specimens of pelagic squids were captured during sampling operations in the Gulf of California (a total of eight cruises: TALUD III, September 1991; TALUD IV, August 2000; TALUD VII, June 2001; TALUD VIII, April 2005; TALUD IX, November 2005; TALUD X, February 2007; TALUD XIII, January 2009) and off the SW coast of Mexico, from Jalisco to Guerrero (TALUD XII, March-April 2008). During these cruises, a total of 113 localities, from 216 to 2300 m depth, were sampled for benthic species. Positional coordinates for each sampling station were obtained using a GPS navigation system. Depth was measured with an EdoWestern analogic recorder (TALUD III-VIII) or a digital recorder (TALUD IX-XIII). All the specimens were presumably captured during the ascent of a modified Agassiz dredge (2.5 m width, 1 m high) and a standard benthic sledge (2.35 m width, 0.9 m high) equipped with a modified shrimp net (ca. 5.5 cm stretched mesh size) with a ca. 2.0 cm (3/4”) internal lining net. In these cases, the depth range at which the gear was operated is provided but does not indicate the depth of capture because the specimens could have been captured between surface and maximum trawling depth at each locality. In two ocasions, sample were obtained with a micronecton net or a mid water Issacs-Kidd trawl. The material collected during this survey is deposited in the Regional Collection of Marine Invertebrates (EMU), at UNAM in Mazatlán, Mexico. The size (mantle length) was measured to the nearest 0.1 mm. Abbreviations are: St., sampling station; ML, mantel length; AD, Agassiz dredge; BS, benthic sledge. Systematic sequence used herein is according to
Five species of small squids were collected during sampling operations. A total of 86 specimens were obtained: Abraliopsis affinis, 46; A. falco, 18; Pterygioteuthis gemmata, 3; P. giardi, 9; and P. hoylei, 10.
Cephalopoda
Class Coleoidea
Superorder Decapodiformes
Order Oegopsida
Family Enoploteuthidae Pfeffer, 1900
Abraliopsis Joubin, 1896
Abraliopsis affinis (Pfeffer, 1912)
Material examined. TALUD III. St. 3B (22°36'36"N; 106°35'54"W), Aug 17, 1991, 1 org. (ML 26.5 mm), Issac Kidds mid-water trawl, 275 m (total depth, 940–950 m) (EMU-10591); St. 14A (24°38'48"N; 108°26'54"W), Aug 19, 1991, 24 orgs. (ML 22.3–34.7 mm), AD operated at 1016–1020 m (EMU-10592). TALUD IV. St. 4 (21°59'N; 106°35'W), Aug 23, 2000, 15 orgs. (ML 20.1–32.1 mm), AD operated at 1200–1290 m (EMU-10593); St. 13 (23°17'30"N; 107°29'51"W), Aug 24, 2000, 1 org. (ML 18.9 mm), BS operated at 860 m (EMU-10597). TALUD VII. St. 12 (23°18'18"N; 107°26'48"W), Jun 6, 2001, 2 orgs. (ML 25.2–27.8 mm), AD operated at 1040–1120 m (EMU-10595); St. 18 (24°14'30"N; 108°16'24"W), Jun 7, 2001, 2 orgs. (ML 27.8–32.1 mm), AD operated at 1040–1120 m (EMU-10596). TALUD VIII. St 21 (26°2'18"N; 110°37'6"W), Apr 19, 2005, 1 org. (ML 22.4 mm), AD operated at 1380 m (EMU 10598).
Abraliopsis falco Young, 1972
Material examined. TALUD IV. St. 25 (24°53'12"N; 108°59'24"W), Aug 26, 2000, 2 orgs. (ML 25.0 mm), AD operated at 778–800 m (EMU-10594). TALUD V, St. 3 (21°59'14"N; 106°28'30"W), Dec 13, 2000, 1 org. (ML 23.5 mm), BS operated at 730 m (EMU-10599). TALUD VII, St. 26 (24°25'24"N; 109°05'21"W), Jun 8, 2001, 1 org. (ML 32.2 mm), BS operated at 1180–1260 m (EMU-10600). TALUD X. St. 14 (27°44'53"N; 111°39'54"W). Feb 11, 2007, 1 org. (ML 24.2 mm), BS operated at 843–905 m (EMU-10601). TALUD XII. St. 2 (16°49'18"N; 100°30'52"W), Mar 28, 2008, 1 org. (ML 21.3 mm), BS operated at 990–1088 m (EMU-10602); St 3 (16°54'35"N; 100°44'10"W), Mar 28, 2008, 2 orgs. (ML 27.1–27.6 mm), BS operated at 1380–1456 m (EMU-10603); St. 10 (17°11'03"N; 101°28'05"W), Mar 28, 2008, 1 org. (ML 32.6 mm), BS operated at 1180–1299 m (EMU-10604); St. 29 (19°19'37"N; 105°26'20"W), Apr 2, 2008, 1 org. (ML 25.4 mm), BS operated at 1609–-1643 m (EMU-10605); St. 30 (19°22'05"N; 105°16'18"W), Mar 28, 2008, 4 orgs. (ML 27.8–-29.3 mm), BS operated at 1350–-1380 m (EMU-10606); St. 30B (19°30'37"N; 105°19'16"W), Mar 26, 2008, 3 orgs. (ML 25.7–30.3 mm), BS operated at 865–1045 m (EMU-10607). TALUD XIII. St. B (26°19'54"N; 110°29'12"W), Jan 13, 2009, 1 org. (ML 30.8 mm), Agassiz dredge, 1295–1330 m (EMU-10608).
Family Pyroteuthidae Pfeffer, 1912
Pterygioteuthis P. Fischer, 1896
Pterygioteuthis gemmata Chun, 1908
Material examined. TALUD VIII. St 15 (25°21'27"N; 110°18'18"W), April 18, 2005, 2 orgs. (ML 12–16 mm), BS operated at 2100 m (EMU-10609); St. 21 (26°02'18"N, 110°37'06"W), April 19, 2005, 1 org. (ML 13 mm), BS operated at 1380 m (EMU-1598).
Pterygioteuthis giardi P. Fischer, 1896
Material examined. TALUD IV. St. 35 (25°39'59"N; 110°11'17"W). Aug 27, 2000, 1 org. (ML 20.6 mm), BS operated at 2000–2100 m (EMU-10615). TALUD VIII. St. 18 (25°50'N; 110°34'W), Feb 12, 2005, 3 orgs. (ML 15.5–17.7 mm), micronecton net, 690 m (total depth 1300 m) (EMU-10616). TALUD IX. St. 22 (26°3'42"N; 110°20'36"W), Nov 14, 2005, 1 org. (ML 19.4 mm), BS operated at 2214–2309 m (EMU-10617). TALUD X. St. 14 (27°44'53"N; 111°36'58"W), 3 orgs. (ML 17.8–19.1 mm), BS operated at 905–943 m (EMU-10618). TALUD XIII, St. 36 (26°07'12"N 110°30'53"W), Jan 15, 2009, 1 org. (ML 18.6 mm), AD operated at 2300–2360 m (EMU-10619).
Pterygioteuthis hoylei Pfeffer, 1912
Material examined. TALUD VIII. St. 15 (25°23'06"N; 110°18'24"W), Abr 18, 2005, 2 orgs. (ML 12.1–12.2 mm), BS operated at 2100 m (EMU-10609); St. 20 (25°56'56"N; 110°43'W), Abr 19, 2005, 2 orgs. (ML 16.2–18.0 mm), BS operated at 1140–1150 m (EMU-10610). TALUD IX. St. 8 (25°07'28"N; 109°49'48"W), Nov 12, 2005, 1 org. (ML 17.6 mm), BS operated at 1657 m (EMU-10611); St.15 (25°21'27"N; 110°18'18"W), Nov 13, 2005, 2 orgs. (ML 19.2 mm), BS operated at 1985–2290 m (EMU-10612); St. 16 (24°23'48"N; 110°36'42"W), Nov 13, 2005, 1 org. (ML 16.4 mm), BS operated at 997–1021 m (EMU-10613); St. 20B (25°58'7"N; 110°40'4"W), Nov 14, 2005, 2 orgs. (ML 17.4–19.6 mm), BS operated at 1229–1343 m (EMU-10614).
All five species examined herein were collected in the central or the southern Gulf of California, or in both (Fig.
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 (Abraliopsis affinis, 46; A. falco, 18). The pyrotheutids were much less abundant in the samples (Pterygioteuthis gemmata, 3; P. giardi, 9; P. hoylei, 10). However, it was decided not to evaluate density of species collected in each sample due to the fact that many specimens were probably able to avoid the nets.
Two species of Abraliopsis were collected during the TALUD survey: A. affinis and A. falco. Abraliopsis felis has been reported from the NE Pacific, between 27° and 43°N (
Our records show that P. gemmata, P. hoylei and P. giardi all occur in the southern Gulf of California. The bathymetric distribution and the southern distribution limit of P. gemmata are unclear.
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, UNAM (TALUD III), and by the Coordinación de la Investigación Científica, UNAM (TALUD IV-XIII). The TALUD project has received laboratory and field work support from CONACyT (Project 31805-N for the TALUD IV-VII cruises), Mexico. The authors thank all scientists, students and crew members who took an active part in the TALUD cruises. Mercedes Cordero Ruiz is acknowledged for preparing the figure and editing the final version of the manuscript. We also thank Alma A. Nieto Flores and Ana K. Barragán (SNI III assistants, CONACyT) for their help with laboratory work during this study. The authors wish to acknowledge use of the Maptool program for graphics in this paper. Maptool is a product of SEATURTLE.ORG. (Information is available at www.seaturtle.org).