Umbrella Squid

Histioteuthis bonnellii (Férussac, 1834)

Histioteuthis bonnellii corpuscula Clarke, 1980:225, figs. 185–188 (upper right), table 35 [new synonym, herein].

The division of Histioteuthis bonnellii into two subspecies by Clarke (1980), when he named H. b. corpuscula from the fringing waters to the north of the SSTC in the Atlantic and western Indian oceans, and recent knowledge of reported (Clarke and MacLeod, 1982; Brandt, 1983) and unreported (NMNZ, NMV, UMML) captures of bonnellii in the subtropical waters of the Tasman Sea and north of New Zealand called for a detailed study of this mainly Atlantic species over its broad geographic range. Although such a study was not possible because of the lack of sufficient material, before (NV) and at the workshop we were able to critically examine the valuable, unreported collection of 53 mostly large juvenile, subadult, and adult specimens of bonnellii (USNM). These specimens were taken from north temperate waters to the SSTC in the Atlantic on the 1971 and 1975/1976 cruises of the R/V Walther Herwig and the 1974 and 1979 cruises of the R/V Anton Dohrn. In addition, recently reported large juveniles and a mature male from Canadian waters (Stephen, 1982; ARC), unreported Atlantic specimens (IOAN, PINRO, UMML), and certain of the above, unreported, southwestern Pacific specimens were examined. At the workshop, we also had the opportunity to examine a specimen of bonnellii, labelled “syntype,” from the Paris Museum, and the recently found holotype of Verrill's synonymous Histioteuthis collinsii (USNM 730893). A total of 92 specimens were examined.

Our investigations failed to distinguish the two nominal subspecies, H. b. bonnellii and H. b. corpuscula, using the characters employed by Clarke (1980), and they were too limited by the available material to define new characters that would clearly separate the possible complex of taxa that could be represented in bonnellii (see “Discussion,” below). Therefore, we have redescribed the species on the basis of mostly late growth stages from over the major portion of its geographic distribution. Unfortunately, the southwestern Pacific was represented only by small juveniles.

DESCRIPTION.—Small to large histioteuthids; single reported mature female, 330 mm ML (Kristensen, 1980; subarctic), can mature at about 90 mm ML in tropical Atlantic and southern subtropical waters; males known to mature at 50–330 mm ML (50–75 mm ML in Atlantic tropical and southern subtropical waters; 172 mm ML in northern Mauritanean Upwelling; 76–330 mm ML in temperate and subarctic waters); mantle conical, moderately short and stout; fins medium-sized to large, length about 40%–60% ML, width about 50%–90% ML; head with 1 nuchal fold; arms medium long to long, about 130%–300% ML, typical arm length formula II = III > I = IV; rings of suckers on all arms with 2–7 broad, blunt teeth on distal or distal and lateral margins; in mature male, distal of arms I modified with 2 widely spaced rows of uniformly small suckers set on enlarged pedestals; inner web well developed, segments between arms I, II, and III (measured at midpoint) about 50%–60% length of longest arms; junctures of segments from arms III and IV closely spaced, appearing as 1; outer web slightly developed in large specimens; buccal membrane 6-membered, with second supports to dorsal sides of arms II, single fourth support with multiple attachments, 1 each to sides of arms IV and to junctures of web segments from arms III and IV; tentacles long, about 200%–350% ML; tentacular club lacking longitudinal cleft on aboral surface; suckers arranged in 6 rows, with those in median 2 rows enlarged to 2 times diameter of ventral marginal suckers; rings of suckers with numerous sharp teeth around entire margins.

Large compound photophores on ventral surface of mantle regularly set in 7 to 8 diagonal rows; uniformly large on anterior of mantle, gradually smaller on posterior ; 3 conspicuous, round, dark, usually large photophores on left posterior margin of ventral surface of head (2 median-most organs with small, reduced, anterior filter element set apart from lateral-most organ, which appears to lack anterior filter element; Figure 8e); circlet of 17 (rarely 16 or 18) large photophores around right eye; 3 longitudinal rows of photophores present on basal portions of all arms; single enlarged, elongate, dark, simple photophore present on ends of arms I–IV (photophore about 7%–17% length of arms I–III, 2%–3% length of arms IV; first seen on arms I–III in early juveniles; usually not seen on arms IV until late juvenile or subadult stages and may not appear in some early maturing individuals).

Dorsal pad of funnel organ with fleshy, median ridge on each lateral arm (often indistinct in small juveniles); ridges do not appear to unite anteriorly; spermatophore short (SpL 2.4–4.6 mm; 1.4%–6.1% ML; 15 spermatophores from 5 specimens, 73–172 mm ML); sperm mass short to moderately long (9.8%–33.9% SpL); cement body of medium length to long (18.6%–67.6% SpL); ejaculatory apparatus of medium length (20.2%–39.1% SpL), with 1 long or 2 to 3 medium long, longitudinal loops of inner tube; ejaculatory-apparatus/cement- body connective complex present (Figure 8a–d, Tables 9, 11); mature egg diameter 2.3 mm (330 mm ML, northwestern Atlantic); gills about 40% ML, with 30–43 lamellae in outer demibranch.

Gladius with short, broad, triangular free rachis; vanes broad, roughly triangular, with long, tapering, nearly straight-sided posterior margins that converge and end in bluntly pointed, cupped coil; lower beak with nearly straight or slightly curved rostral edge; hood (very broad in large specimens) with well-defined notch above crest; wing fold low, broad, often with sharp lateral edge or distinct lateral ridge; lateral wall bisected by well-developed median ridge extending to free corner; radula heterodont; first and second laterals asymmetrical, with rudimentary cusps on outer ends of rather long, narrow bases; weak marginal plates present (Mediterranean juvenile).

ORIGINAL REFERENCE.—Férussac, 1834:355.

TYPE LOCALITY.—Mediterranean, off Nice.

DEPOSITION OF TYPE.—Holotype: Whereabouts unknown; sex undetermined, 70 mm ML; neotype not selected.

DISTRIBUTION.—Histioteuthis bonnellii is widely, but unevenly, distributed in the Atlantic north of the SSTC and extends eastward across the Indian Ocean and into the western Pacific in subtropical waters fringing the convergence (Figure 9). Occurring throughout subarctic and north temperate waters, including the eastern and western Mediterranean, numerous cruise collections (1980 Amsterdam Mid-North Atlantic Plankton Expedition (USNM); R/V Anton Dohrn 1979 Sargasso Sea Expedition; R/V Atlantis 11–78; and research vessels Dana, Oregon, Pillsbury, and others) have shown the species to be absent from northern subtropical and western tropical waters and from the Gulf of Mexico. The geographic range of bonnellii in the eastern Atlantic south of temperate waters could be disjunct as shown by the extensive cephalopod collections taken on the Cape Town-Madeira transect of the R/V Walther Herwig in 1971. On this cruise, 31 large juveniles, subadults, and adults were captured at eight of the 13 (62%) pelagic-trawl stations made in the Mauritanean Upwelling and tropical waters between 21°N and 16°S. No captures were made at the three stations in subtropical waters to the north of the above range or at the six stations to the south until the species was again encountered off Cape Town at 35°S in the southern sector of the Benguela Current. The scarcity or absence of bonnellii in the northern sector of the current is further supported by the lack of the species in the collections made by the R/V Professor Shtokman (cruise 14, 1985) and R/V Akademik Kurchatov (cruise 43, 1986) during their work in Namibian waters between 17°S–26°S and 10°E–14°E. In this area, the closely related SSTC species, macrohista, was found to be common, along with H. reversa.

Farther south, bonnellii inhabits a narrow belt of subtropical waters between about 28°S–40°S that borders the SSTC and extends from off Mar del Plata, Argentina, where the species was encountered by the R/V Walther Herwig on both the 1971 and the 1975/1976 cruises, eastward to about 180°. In addition to the above unreported R/V Walther Herwig captures, our knowledge of the species’ occurrence between these southern latitudes is furnished by the published reports of Voss (1969), Clarke (1980; as H. b. corpuscula), Clarke and MacLeod (1982; as H. b. corpuscula), and Brandt (1983) and by unpublished records from the Atlantic and western Indian oceans (K. Nesis) and from the Australia–New Zealand area (E. Förch, C. Lu, and N. Voss). During the Socotra Island–Walters Shoal (13°N–34°S) transect of the western Indian Ocean made by the R/V Vityaz in 1988/1989, the species was encountered between 25°S and 34°S, with five of the six (83%) stations positive for the species located between 28°S and 34°S in the vicinity of Walters Shoal. There, bonnellii was found to be second to miranda in abundance among congeners. The cephalopod fauna in southern subtropical waters east of New Zealand is poorly known, but the preference clearly shown by bonnellii for high or relatively high productivity waters and the avoidance of oligotrophic areas suggest that the species can not inhabit the less productive central waters of the Pacific. Although the distributions of bonnellii and its transitional sibling species, macrohista, overlap in the fringing waters immediately to the north of the SSTC, the north-south transects of the convergence in the western Atlantic made during the 1975/1976 cruise of the R/V Walther Herwig revealed a total absence of bonnellii in convergent waters but an abundance of macrohista.

Histioteuthis bonnellii inhabits a broad vertical range between the upper 100 m to possibly 2000 m. Lu and Clarke (1975b) report the only closing-net captures, that of a 9 mm ML juvenile at 305–400 m during the day and of a 31 mm ML juvenile at 240–265 m at night in the eastern tropical Atlantic. Captures by open nets fishing maximum depths of 100–200 m show juveniles of less than 20 mm ML to inhabit these upper waters during both day and night over the entire geographic range of the species. Larger juveniles and subadults have been found at night mostly between about 200 m and 1000 m, but large subadults have been collected at the surface in areas of upwellings in the Mediterranean off Nice and Messina. Mature males were taken by the R/V Walther Herwig in the Mauritanean Upwelling and eastern tropical Atlantic while fishing depths of 1300–2200 m. In North Atlantic temperate and subarctic waters, a mature male and a mature female have been reported from the surface 100–325 m (Kristensen, 1980; Stephen, 1982:115 (reported as H. celetaria celetaria, see “Discussion”).

Histioteuthis bonnellii, the umbrella squid, is a species of cock-eyed squid belonging to the family Histioteuthidae.

off Newfoundland and New York to Western Europe

epi-mesopelagic

Known from seamounts and knolls