Research Article |
Corresponding author: Michel E. Hendrickx ( michel@ola.icmyl.unam.mx ) Academic editor: Sammy De Grave
© 2015 Michel E. Hendrickx, Vanesa Papiol.
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Citation:
Hendrickx ME, Papiol V (2015) Distribution of Benthesicymus tanneri Faxon, 1893 (Dendrobranchiata, Benthesicymidae) off the west coast of Mexico and notes on its morphology. ZooKeys 473: 119-136. https://doi.org/10.3897/zookeys.473.8956
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A large series of specimens of Benthesicymus tanneri Faxon, 1893 (Dendrobranchiata; Benthesicymidae) was collected during an extensive survey of deep-water invertebrate fauna off western Mexico. In total, 61 males and 122 females (M:F ratio = 1:2) from 44 sampling stations were examined, considerably increasing the number of known specimens and sampling localities for this species which is widely distributed along the Pacific coast of Mexico. The collection is the largest available for this species to date and presents first records from off the west coast of the Baja California Peninsula and a slight increase of the northernmost record within the Gulf of California. On the whole, females grew larger than males. The petasma of males of different sizes and the female thelycum of B. tanneri are illustrated. The petasma of B. tanneri presents a ventrolateral crescent-shape process otherwide found only in B. tirmiziae Crosnier, 1978 and in B. bartletti S.I. Smith, 1882. A key to the four species of Benthesicymus presently known from the eastern Pacific is presented.
Benthesicymus tanneri , eastern Pacific, distribution, key to species
Benthesicymidae is a relatively large family of shrimps that contains 39 species within five genera. The most species-rich genera are Gennadas (16 species) and Benthesicymus (15 species) (
Characters used by
To date, four species have been certainly recorded in the eastern Pacific. Benthesicymus altus is distributed from California, USA, to the Galapagos Islands, but it also occurs in the Atlantic and Indo-Pacific (Guzmán and Wicksten 2000). Benthesicymus tanneri is known from California, USA, and the Gulf of California (north to 27°34'N; 110°53'W), Mexico, to Chile (21°19'S) (
Benthesicymus tanneri is a moderate large species, with females reaching up to 99 mm total length (
Material collected in Mexican waters during the TALUD cruises III-VII (1991–2001) in the SE Gulf of California was reported by
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 Benthesicymus tanneri were captured during sampling operations off the west coast of the Baja California Peninsula (TALUD XV, July-August 2012; TALUD XVI-B, May-June 2014), in the Gulf of California (a total of nine cruises: TALUD III, September 1991; TALUD IV, August 2000; TALUD V, December 2000; TALUD VI, March 2001; TALUD VII, June 2001; TALUD VIII, April 2005; TALUD IX, November 2005; TALUD X, February 2007), and off the SW coast of Mexico, from Jalisco to Guerrero (TALUD XII, March-April 2009). During these cruises, a total of 228 localities were sampled, from 377 to 2394 m depth. 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-XVI-B). All the specimens were captured with benthic gear, including an Agassiz dredge (2.5 m width, 1 m high) and a standard benthic sledge (2.35 m width, 0.9 m high), both equipped with a modified shrimp net (ca 5.5 cm stretched mesh size) with a ca 2.0 cm (3/4”) internal lining net. The material collected during this survey is deposited in the Regional Collection of Marine Invertebrates (EMU), at UNAM in Mazatlán, Mexico. The size (carapace length, CL) of all the specimens was measured to the nearest 0.1 mm and size distributions of B. tanneri were explored by sex for the entire population sample in the Mexican Pacific. Sexual differences in CL were tested using a Mann-Whitney U test (
Specimens of B. tanneri were collected in 44 of the 228 stations visited during the survey (Figure
TALUD III. Material reported by
TALUD IV. Material reported by
TALUD V, St. 5 (22°0'57"N; 106°40'0"W), Dec 13, 2000, 1F (CL 36.3 mm), BS, 1515–1620 m (EMU-5540-A); St. 6 (22°N; 106°48'5"W), Dec 13, 2000, 1F (CL 41.1 mm), BS, 1950–2010 m (EMU-5540-B); St. 19 (23°17'30"N; 107°29'51"W), Dec 15, 2000, 1M (CL 31.1 mm), 3F (CL 29.1–36 mm), BS, 1180–1200 m (EMU-5523-A); St. 26 (24°15'18"N; 108°24'6"W), Dec 16, 2000, 2M (CL 29–30.7 mm), 2F (CL 32–34.2 mm), BS, 1280–1310 m (EMU-5523-B).
TALUD VI, St. 12 (23°18'36"N; 107°26'56"W), Mar 14, 2001, 1M (CL 32.5 mm), 1F (CL 34.8 mm), BS, 1050–1160 m (EMU-5539-A); St. 19 (24°16'24"N; 108°24'18"W), Mar 15, 2001, 1F (CL 50.4 mm), BS, 1160–1200 m (EMU-5539-B); St. 26 (24°56'18"N; 109°6'42"W), Mar 16, 2001, 1M (CL 33.4 mm), 1F (CL 25.2 mm), BS, 1190–1270 m (EMU-5997-A); St. 27 (25°1'12"N; 109°11'36"W), Mar 16, 2001, 1F (CL 32.3 mm), BS, 1580–1600 m (EMU-5539-C); St. 34 (25°43'50"N; 109°53'59"W), Mar 17, 2001, 1M (CL 31.9 mm), 2F (CL 3025–33.6 mm), BS, 1240–1270 m (EMU-5997-B), and 7M (CL 31.4–34.8 mm), 12F (CL 30.5–42.5 mm), and 3 unsexed specimens (14.5–21.4 mm).
TALUD VII, St. 4 (22°3'18"N; 106°34'42"W), Jun 5, 2001, 1F (CL 37.8 mm), BS, 1190 m (EMU-5541); St. 19 (24°16'12"N; 108°23'42"W), Jun 7, 2001, 1M (CL 11.2 mm) and 1F (CL 34.7 mm), BS, 1160–1180 m (EMU-6004-A); St. 33B (26°6'30"N; 110°6'42"W), Jun 9, 2001, 1F (CL 23.0 mm), BS, 1260–1300 m (EMU-6004-B).
TALUD VIII, St. 10 (24°58'12"N; 110°16'6"W), Apr 17, 2005, 1M (CL 30.4 mm), and 1F (CL 11.2 mm), BS, 1500 m (EMU-8143); St. 3 (24°32'36"N; 109°30'30"W), Apr 16, 2005, 2M (CL 31.9–34.7 mm), 3F (CL 29.2–35.7 mm), BS, 1100 m (EMU-8147).
TALUD IX, St. 20B (25°58'7"N; 110°40'4"W), Nov 14, 2005, 2F (CL 33.7–36.2 mm), BS, 1229–1343 m (EMU-8236).
TALUD X, St. 10 (27°50'5"N; 112°10'7"W), Feb 10, 2007, 1F (CL 32.3 mm), BS, 1399–1422 m (EMU-8030); St. 18 (27°9'6"N; 111°46'54"W), Feb 12, 2007, 1F (CL 31.3 mm), BS, 1526 m (EMU-8118); St. 30 (26°36'50"N; 110°21'10"W), Feb 15, 2007, 1M (CL 29.9 mm), BS, 1203–1213 m (EMU-8203).
TALUD XII, St. 5 (16°58'28"N; 100°55'20"W), Mar 28, 2008, 1F (CL 53.3 mm), BS, 1925–1977 m (EMU-8872); St. 9 (17°10'15"N; 101°37'23"W), Mar 28, 2008, 6F (CL 30.1–35.3 mm), BS, 1392–1420 m (EMU-8874); St. 10 (17°11'18"N; 101°28'30"W), Mar 29, 2008, 3F (CL 21.1–38.7 mm), BS, 1180–1299 m (EMU-10500); St. 13 (17°45'16"N; 102°0'29"W), Mar 30, 2008, 1F (CL 30 mm), BS, 1198 m (EMU-8904); St. 28 (18°50'19"N; 104°34'14"W), Apr 2, 2008, 1F (CL, 38.1 mm), BS, 1101–1106 m (EMU-10499); St. 29 (19°19'37"N; 105°26'20"W), Apr 2, 2008, 1F (CL 44.7 mm), BS, 1609–1643 m (EMU-8873).
TALUD XV, St. 1 (23°18'40"N; 111°19'37"W), Aug 4, 2012, 1F (CL 40.2 mm), BS, 750–850 m (EMU-10435); same station, 5M (CL 17.9–29.1 mm) and 7F (CL 25.3–41.1 mm), BS, 750–850 m (EMU-10434); St. 2 (23°12'2"N; 111°20'50"W), Aug 4, 2012, 4M (CL 32–33.9 mm), 5F (CL 23.2–40.6 mm) and 1Juv. (CL 12.4 mm), BS, 1118–1150 m (EMU-10436); St. 3 (23°9'N; 111°20'W), Aug 4, 2012, 1F (CL 36.4 mm), BS, 1395–1465 m (EMU-10433); St. 5C (23°16'42"N; 110°54'55"W), Aug 5, 2012, 8M (CL 20.5–35.5 mm), BS, 980–1036 m (EMU-10496-A); same station 25F (CL 20.3–40.5 mm), 1M (CL 13.4 mm), BS, 980–1036 m (EMU-10496-B); St. 5F (22°58'15"N; 110°40'17"W), Aug 5, 2012, 1F (CL 39.3 mm), BS, 1035–1108 m (EMU-10432); St. 8 (24°25'48"N; 112°38'6"W), Jul 30, 2012, 1M (CL 29.8 mm), 3F (CL 23.2–41.1 mm), BS, 1212–1235 m (EMU-10431); St. 24 (27°5'42"N; 114°35'30"W), Aug 1, 2012, 2F (CL 25–32.6 mm), BS, 772–786 m (EMU-10430).
TALUD XVI-B, St. 3 (28°42'36"N; 115°50'42"W), May 23, 2014, 2F (CL 30.1–31.0 mm), BS, 1350–1365 m (EMU-10623) St. 6 (29°08'9"N; 115°33'25"W), May 24, 2014, 10M (CL 16.4–29.9 mm) and 9F (CL 16.7–29.5 mm), BS, 1004–1102 m (EMU-10498); St. 8 (29°23'28"N; 115°45'W), May 31, 2014, 1M (CL 35.4 mm), 1F (CL 27 mm), BS, 1416–1480 m (EMU-10438); St. 16 (29°51'N; 116°9'W), May 29, 2014, 4F (CL 23.2–37.2 mm), BS, 1425–1360 m (EMU-10441); St. 23 (30°56'N; 116°40'33"W), May 27, 2014, 1M (CL 33.3 mm), 2F (CL 30.1–32.7 mm), BS, 1296–1340 m (EMU-10439); St. 26 (31°46'3"N; 116°58'12"W), May 26, 2014, 1F (CL 31.4 mm), BS, 982–989 m (EMU-10437); St. 27 (31°42'21"N; 117°13'W), May 27, 2014, BS, 1394–1397 m, 1F (CL 34.7 mm) (EMU-10440) and 1 F (CL 30.5 mm) (EMU-10497).
With 187 specimens available (61 males, CL 11.2–35.5 mm; 122 females, CL 16.7–53.3 mm; 3 unsexed; and 1 juvenile, CL 12.4) (M:F = 1:2), the collection of B. tanneri from off western Mexico came from 44 stations and is the largest available to date for this species (Figure
The syntype series, collected by the “Albatross”, contained 56 males and 78 females (134 specimens) from 22 lots captured over a wide latitudinal range (1°3'S to 27°34'N), and included material from 4 stations in Mexico: off Acapulco and Islas Tres Marías, and in the vicinity of Guaymas (Figure
According to
The material examined herein was collected between 750 and 2010 m depth with bottom sampling gear. One specimen (TALUD III, St. 17) was collected with a mid-water trawl hauled from surface to 770 m depth, in a locality where total depth was 1560 m. All species of Benthesicymus occur in deep water and the general depth range for B. tanneri is 606–2422 m (Table
Currently known distribution, depth range and maximum size for the species of Benthesicymus worldwide. Species list updated according to
Species | Distribution | Depth range | Size | Source |
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Benthesicymus altus Spence Bate, 1881 | Eastern, central and western Pacific; Atlantic and Indian Oceans | 485 m (MW); 916–4089 m; 4130 m (BT) | CL 23.5 mm; TL 120 mm |
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Benthesicymus armatus MacGilchrist, 1905 | Arabian Sea | 2753 m | TL 157 mm |
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Benthesicymus bartletti S. I. Smith, 1882 | Atlantic, eastern Indian and western Pacific Oceans | 600–5777 m | CL 34.2 mm; TL 115 mm |
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Benthesicymus brasiliensis Spence Bate, 1881 | Atlantic, southern Pacific | 600–4720 m | TL 152 mm |
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Benthesicymus cereus Burkenroad, 1936 | Atlantic | 1645–1727 m | CL 25 mm; TL 76 mm |
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Benthesicymus crenatus Spence Bate, 1881 (type species) | Northwestern and central Pacific | 3530 m (BT); 3530–6350 m; 5469–9726 m | TL 200 mm |
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Benthesicymus howensis Dall, 2001 | Western Pacific | 1325 m | CL 24.0 mm |
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Benthesicymus investigatoris Alcock & Anderson, 1899 | Indo-West Pacific; SW Pacific | 0–1300 (IK); 1213 (AT); 580–1690 m | CL 27.5 mm; TL 89.5 mm |
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Benthesicymus iridescens Spence Bate, 1881 | Atlantic Ocean | 3890–6500 m | TL 150 mm; CL 47 mm |
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Benthesicymus laciniatus Rathbun, 1906 | Eastern Pacific | 1471–3393 m | CL 42.6 mm |
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Benthesicymus seymouri Tirmizi, 1960 | Indian Ocean | 1789–3716 m | CL 40–59 mm |
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Benthesicymus strabus Burkenroad, 1936 | Pacific Ocean | 3530 m (BT) | CL 39.5 mm |
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Benthesicymus tanneri Faxon, 1893 | Eastern Pacific | 606–2422 m | TL 121 mm |
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Benthesicymus tirmiziae Crosnier, 1978 | Indian Ocean | 1920–2249 m | 33 mm CL, 100 mm TL |
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Benthesicymus urinator Burkenroad, 1936 | Indo-Pacific | 1789–3716 m; 2500–4200 m; 4120 m (BT) | CL 25.0 mm |
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Of the 15 recognized species of Benthesicymus (Table
In their identification key of Group II,
While studying fine morphology of B. carinatus (now included in Altelatipes),
The fully developed petasma (Figure
The female thelycum of B. tanneri was roughly illustrated by
The color of fresh specimens was described by
Although it reaches a size (i.e., over 115 mm total length) comparable with other species of Dendrobranchiata used as food, B. tanneri is not currently subject to any commercial exploitation. It has been considered a potential fisheries resource for the area (see
1a | Posterolateral margin of fifth abdominal somite with small spines | B. laciniatus |
1b | Posterolateral margin of fifth abdominal somite without spines | 2 |
2a | Petasma ventral margin strongly convex, without lateral crescent-shape process. Thelycum sternite XIII plate smooth, without small pits and setae | B. investigatoris |
2b | Petasma ventral margin straight to slightly concave, with or without lateral crescent-shape process. Thelycum sternite XIII plate bearing small pits | 3 |
3a | Petasma with strong ventrolateral crescent-shape process. Thelycum sternite XIII plate longer than wide, shallow anterior notch | B. tanneri |
3b | Petasma without ventrolateral crescent-shape process. Thelycum sternite XIII plate wider than long, deep anterior notch | B. altus |
Ship time was provided by the Instituto de Ciencias del Mar y Limnología, UNAM (TALUD III), by the Coordinación de la Investigación Científica, UNAM (TALUD IV-XVI-B), and partly supported by CONACyT (project 179467 for the TALUD XV and XVI-B cruises). The TALUD project has received laboratory and field work support from the DGAPA (PAPIIT IN-217306–3 and PAPIIT IN-203013–2) and from CONACyT (Project 31805-N for the TALUD IV-VII cruises; project 179467 for the TALUD XV and XVI-B cruises), Mexico. The authors thank all scientists, students and crew members who took an active part in the TALUD cruises. We also thank Dr. Rafael Lemaitre, National Museum of Natural History, Maryland, USA, for revising type material of B. tanneri deposited in the USNM and providing useful information on its morphology, and Adam Baldinger, Museum of Comparative Zoology at Harvard, Massachussets, USA, for providing the photograph in Figure