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Comprehensive Description

provided by Smithsonian Contributions to Zoology
Histioteuthis heteropsis (Berry 1913)

Melagrotcuthis hoylei —Berry, 1912b, p.305, text figs. 13–16; pl.50, figs. 1–3; pl.51, figs. 1–5; pl.52, figs. 6–7.

Calliteuthis (Meleagroteuthis) heteropsis Berry, 1913, p.75.

Histioteuthis heteropsis.—Voss, 1969, p.815.

DESCRIPTION.—The mantle is short and broad; it tapers gradually posteriorly to a blunt tip. The mantle margin projects slightly in the region of the dorsal and ventral locking-cartilages. The mantle wall is very thick, but moderately gelatinous.

The fins are short, about 35–10% of the mantle in length and about 50–55% of the mantle in total width. Each fin is roughly semicircular and has free anterior and posterior lobes. Medially, the fins touch one another only at the posterior end where they extend slightly past the tip of the mantle. Anteriorly, the fin insertions are broadly separated from one another.

The funnel is short. The funnel locking-cartilage has a broad, simple, generally straight groove that is deepest in the midportion. This structure opposes a straight or slightly curved ridge on the mantle, the anterior end of which is flanked on either side by additional short broad ridges. The dorsal pad of the funnel organ has an inverted V-shape with a small papilla at the anterior apex. The ventral pads are oval. A funnel valve is present.

The head is broad and asymmetrical due primarily to the unequal development of the eyes; the left eye has almost 1 2/3 the diameter of the right. An anterior sinus is present on each eyelid. A nuchal crest and nuchal folds are not clearly developed. The nuchal cartilage is short and much broader anteriorly than posteriorly.

The arms are broad and short, although slightly greater than the mantle in length. Aboral keels are well developed only on the midportion of arms III; they are represented by faint ridges on arms I and II. The lateral keels are well developed on arms IV. Low, thick, gelatinous protective membranes, lacking distinct trabeculae, are present on all arms. The arms have biserial suckers. The suckers are globular and have relatively narrow outer rings, and inner rings with about 8–10 rounded to truncate teeth on the distal margin. All arms have low inner and outer webs.

The tentacles are short and have small (30–40% of M.L.) expanded clubs. The manus has 7 irregular longitudinal rows of suckers. The third and fourth rows from the dorsal margin bear the largest suckers; the remaining suckers become progressively smaller toward the club margins. Sucker rows near the ventral margin of the club extend slightly farther proximally than the others. Proximally, the dactylus has 7–8 irregular longitudinal rows of suckers; however, these are not all continuous with the rows on the manus. At the base of the dactylus, a new row begins along the dorsal margin giving a total of 8 rows for a short distance; however, rows that have continued on from the manus begin terminating, and approximately at the midpoint of the dactylus the number has dropped to 6 rows, then shortly to 5, and finally to 4 rows at the tip of the dactylus. The extreme tip is occupied by a circular pad of small suckers. The largest suckers of the manus have large, pointed or slightly truncated teeth around the entire margin of the inner chitinous ring. The teeth of the distal margin are only slightly larger than those of the proximal margin in large specimens. In smaller specimens, the size difference is much greater. A trabeculate protective membrane extends along the entire ventral margin of their club, but dorsally it disappears about the middle of the dactylus. A dorsoaboral keel is present on the dactylus.

The carpal locking-apparatus begins in an oblique line of 3 suckers with alternating pads along the dorsal-basal part of the manus. Three to 4 suckers follow with alternating pads that extend proximally in a single line along the dorsal margin of the club and onto the tentacular stalk. Medial to the end of this series is a single small suckers and pad aligned longitudinally and situated slightly to the ventral side of the midline. The major series of suckers and pads crosses from the dorsal margin of the stalk to the ventral margin. Elements transversing the stalk may consist either of 2 suckers, or 2 pads, or 2 suckers and 2 pads. Along the ventral margin of the tentacular stalk, the locking-apparatus consists of a single line of pairs of suckers alternating with pairs of pads. There are 2–3 sets of suckers in this series. The last element in the series is a single sucker set some distance proximal to the alternating suckers and pads.

Histioteuthis heteropsis is covered with numerous small, anteriorly directed photophores. On the anterior portion of the ventral surface of the mantle, photophores are aligned roughly in closely packed transverse rows. There are approximately 40–45 photophores along the free edge of the mantle. On the posterior portion, the photophores are irregularly distributed. The number of photophores decreases laterally; on the dorsal surface of the mantle they are sparse and smaller in size. Photophores are absent from the ventral surface of the fins, but occur in small numbers on the dorsal surfaces. The funnel lacks photophores. The ventral surface of the head is covered with many irregularly distributed photophores. About 19–21 photophores are situated at the edge of the circular eyelid of the right eye and only a few, small, scattered light organs are present near the eye opening of the right eye and none of these lies on the edge of the eyelid. Large photophores are scattered over the right side of the head, but the left side has smaller and less numerous photophores. The dorsal surface of the head has small, scattered photo phores. At the base of the ventral arms there are 8–9 longitudinal rows of light organs. These decrease to 7 about halfway along the arm length. Arms III have 4 rows near the arm base, but only the ventral row extends to the arm tip. Arms I and II each has a distinct row along its ventral border which extends to the arm tip. Other portions of these arms bear small, scattered photophores.

The buccal membrane has 7 lappets, and the primary buccal connectives attach to the dorsal borders of arms I, II, and IV and to the ventral border of arms III. An accessory connective attaches to the ventral border of each arm I.

This animal has a uniform purplish red coloration.

TYPE LOCALITY.—Monterey Bay, California, eastern North Pacific Ocean.

LOCATION OF TYPES.—United States National Museum and personal collection of S. S. Berry, numbers 108, 110.
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bibliographic citation
Young, Richard E. 1972. "The systematics and areal distribution of pelagic cephalopods from the seas off Southern California." Smithsonian Contributions to Zoology. 1-159. https://doi.org/10.5479/si.00810282.97

Comprehensive Description

provided by Smithsonian Contributions to Zoology
Histioteuthis heteropsis (Berry, 1913)

The second member of the meleagroteuthis species group, H. heteropsis, replaces its wide-occurring sibling species, meleagroteuthis, in the transitional waters of the California Current and Peru-Chile Current. Over the years since the studies of heteropsis by Voss (1969) and Young (1972), 89 unreported specimens have accumulated in the collections of the IOAN, SIO, UMML, and USNM. We examined this material before and at the workshop and considered the reports of captures by Nesis (1973a) and Jefferts (1983) in our new study. Our description is based largely on large juveniles, subadults, and adult males, 36–132 mm ML, but because most of the known material from the Peru-Chile Current falls below this size range, we also have included smaller juveniles from that area for information on photophore patterns and on other characters that essentially are unaffected by growth.

DESCRIPTION.—Small to medium-sized histioteuthids; males known to mature at 54–89 mm ML; female size at maturity not known, largest known specimen 132 mm ML (SIO uncat. lot 6303-Cobb 58–7), immature; mantle moderately elongate; fins of medium size, length about 27%–40% ML, width about 48%–56% ML; head with no nuchal fold apparent; arms of medium length, about 100%–135% ML, approximately subequal; rings of suckers on all arms typically with 5–15 low, often poorly defined, round or square teeth on distal and lateral margins, except on distal ends of arms where rings more incised and on entire margins; in mature males, suckers on basal portions of all arms slightly enlarged, approximate distal – of arms I modified with suckers of equal size on enlarged pedestals; inner web connecting arms I, II, and III approximately 11%–23% of length of longest arm; outer web developed to somewhat lesser degree, resulting in deep pocket between arms and web segments; buccal membrane 7- membered, second supports to dorsal sides of arms II, or bifurcate to ventral sides of arms I and dorsal sides of arms II; fourth supports without secondary connectives; tentacles long, about 140%–200% ML; tentacular club lacking longitudinal cleft on aboral surface; suckers on manus closely arranged in about 6–8 rows, moderately enlarged in median rows to about 2 times ventral marginals; rings of enlarged suckers with about 30–34 sharp or blunt teeth around entire margins.

Compound photophores uniformly small (~1.5 mm long in 63 mm ML specimen) and densely arranged on anterior of ventral surface of mantle, of diminishing size and density on posterior ; photophores on ventral surface of head of same approximate size and density as on anterior ventrum of mantle except more widely spaced on left side; circlet of about 19–21 (range, 17–23) photophores around right eye (Table 17); arms IV with 8–10 longitudinal rows of photophores on basal portions; enlarged, maturity-related, simple photophores not known to occur on mantle, head, or arms.

Dorsal pad of funnel organ fleshy, unsculptured; spermatophore short (SpL 1.8–2.8 mm; 2.4%–3.4% ML; from 4 specimens, 54.6–88.5 mm ML, California Current); sperm mass moderately short (10.9%–16.6% SpL); cement body long (55.5%–63.6% SpL); ejaculatory apparatus of medium length (~26.2%–29.5% SpL), with single longitudinal loop of inner tube; ejaculatory-apparatus/cement-body connective complex well developed; mature egg not known; gills about 54%–59% ML, with 37–40 lamellae in outer demibranch.

Gladius with straight, moderately slender rachis; vanes with rounded, convex (Peru-Chile Current specimens), or slightly angular (California Current specimens) shoulders, with hourglass-shaped midportion; vanes ending posteriorly in rounded cupped coil; lower beak with jaw angle not recessed, visible in profile; hood notch shallow, crest fold weak, median ridge on lateral wall strong, extending to free corner; radula with first and second laterals slightly asymmetrical, third laterals long, saber-shaped; marginal plates weakly developed, tear-shaped.

Skin color purplish red.

ORIGINAL REFERENCE.—Berry, 1913:75; original illustrations, Berry, 1912, figs. 13–16, pl. 50: figs. 1–3, pl. 51, pl. 52: figs. 5–7.

TYPE LOCALITY.—Eastern North Pacific, off Santa Barbara Island, California, 590–818 m.

DEPOSITION OF TYPES.—Holotype: USNM 214620, female, 59 mm ML, R/V Albatross sta 4416, 12 Apr 1904, by subsequent designation. No longer extant.

Paratype: Department of Invertebrate Zoology, California Academy of Sciences, San Francisco, CASIZ 029130, female, 48 mm ML, R/V Albatross sta 4538, Monterey Bay, California, 31 May 1904, 1453–1592 m, by subsequent designation.

DISTRIBUTION.—Histioteuthis heteropsis is an eastern Pacific transitional species (Figure 17). Collecting data indicates a north-south disjunction in its distributional pattern. In the north, heteropsis is restricted to the California Current system where it is common over its known range, between about 24°N and 45°N (Young, 1972; Jefferts, 1983; Voss et al., 1992; unreported SIO collection). In the current, heteropsis occurs with its less common congeners, hoylei, H. celetaria pacifica, and H. corona berryi. The species is essentially absent from equatorial waters, which are normally inhabited by the closely related meleagroteuthis and where but a single capture of heteropsis has been reported (Nesis, 1973a; from 00°38′S, 89°29′W). In the southern sector of its geographic range, heteropsis appears to be restricted to the Peru-Chile Current where it is common between about 30°S and 36°S, 72°W and 75°W, judging from unreported collections made during R/V Eltanin cruise 25 (USNM) and the South Tow Expedition (SIO) and from several reported captures (Voss, 1969; Nesis, 1973a, 1973b; Retamal and Orellana, 1977) from that area. The exact extent of the distribution of heteropsis in the current is not known.

In the California Current, capture data from open nets show that heteropsis lives between about 300 m and 900 m during the day, with greatest concentration between about 500 m and 700 m, and at night lives between the surface and about 400 m, with greatest concentration between about 300 m and 400 m (Roper and Young, 1975). One mature male for which we have the time of capture was taken in midwater at 800–850 m during the day. Roper and Young found only juveniles of less than 20 mm ML in the nighttime hauls from the upper 200 m. In the Peru-Chile Current, juveniles of less than 20 mm ML also were the only size group present in the single known tow from the surface 200 m layer that was successful in capturing the species.
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bibliographic citation
Voss, N. A. and Sweeney, M. J. 1998. "Systematics and Biogeography of cephalopods. Volume II." Smithsonian Contributions to Zoology. 277-599. https://doi.org/10.5479/si.00810282.586.277

Histioteuthis heteropsis

provided by wikipedia EN

Histioteuthis heteropsis (H. heteropsis), also known as the strawberry squid, is a species of small cock-eyed squid.[2] The scientific nomenclature of these squid stems from their set of differently sized eyes, one being small and blue and the other being large and yellow. It is thought that the large eye is used to see objects against dim light, while the smaller eye is more able to view bioluminescent light sources.[3] The squid's vernacular name arose due to its rich red skin pigmentation and the presence of photophores along its body, making it appear like a strawberry with seeds.[2]

H. heteropsis live in the ocean's mesopelagic zone and are found in the California Current and the Humboldt Current.[4] Little is known about their specific feeding and mating behaviors, although their inking patterns have been subject to study.[4] They are not easily disturbed, and only ink when provoked.[5]

H. heteropsis was discovered by Berry in 1913 and exhibited publicly for the first time at the Monterey Bay Aquarium on June 27, 2014.[6]

Description

Members of the species H. heteropsis are small squids, with mature males averaging 54-89 mm in length, and have a purplish red skin pigment.[4]

Eyes

The eyes of H. heteropsis are dimorphic both in size and in lens pigmentation for specialized vision in the ocean's mesopelagic zone (200-1000 meters below the ocean surface).[3] The different properties of the squid's eyes allow it to see a variety of different light sources present in its habitat, primarily downwelling sunlight and bioluminescence.[3] H. heteropsis hatchlings are born with identical eyes of the same size and pigmentation.[3] As they develop, the left eye becomes larger and more pigmented.[3] By adulthood, the left eye can grow to be over twice the size of the right eye and has a distinct yellow lens pigmentation.[3] In a 2017 study conducted by Kate Thomas, Bruce Robinson, and Sönke Johnsen, it was found that the large left yellow eye is oriented upwards for viewing objects in dim sunlight and the smaller right blue eye is oriented downwards for viewing bioluminescence.[3] While the larger eye can detect bioluminescence fairly well, the smaller eye struggles to view black objects in dim light.[3]

Photophores

Small photophores, which are glandular, light-producing organs, are found in high concentrations along the entire body of H. heteropsis.[7] The photophores are more dense near the anterior head region of the squid and become smaller and farther apart near the posterior end.[7] Apart from H. meleagroteuthis, H. heteropsis is the only member in the family Histioteuthidae to display such small and highly concentrated photophores.[7] H. heteropsis mainly uses its photophores for two purposes: counter-illumination and concealing prey.[8] In counter-illumination, the squid produces blue light from its photophores so that, when viewed from above, it blends in with the downwelling sunlight and effectively erases its silhouette.[8] This type of bioluminescence is characterized by consistent light production, in contrast to bioluminescence used for concealing prey, which is characterized by short bursts of intense light or "flashes".[8] Although the exact purpose for this particular use of bioluminescence is unknown, the heavily pigmented oral cavity and interbrachial membrane of H. heteropsis and some other squids suggests that luminescence by the prey threatens the predator in some way.[8]

Reproductive organs

H. heteropsis males do not possess a hectocotylus as is common in other mesopelagic squid species, although they do have a penis which is used to transfer spermatophores to the female during copulation.[4] During maturation, the penis grows until it can extend out of the mantle cavity.[4] The spermatophores of H. heteropsis have short sperm masses and are stored in a looped Needham's sac.[7] Female H. heteropsis squids have a singular ovary where the oocytes are developed.[9] Although not much is known about female reproductive systems in H. heteropsis specifically, other members of the family Histioteuthidae show significant oocyte resorption (oosorption) during maturation.[10]

Habitat

H. heteropsis is generally found at ocean depths of 200-1000 meters (0.12-0.62 miles), which is considered part of the ocean's mesopelagic, or twilight, zone.[3] The species undergoes diurnal vertical migration, where they are found at lower depths during the day and migrate up the water column at night.[11] In a study about vertical distributions of pelagic cephalopods conducted by Clyde Roper and Richard Young, it was found that, during the day, most H. heteropsis specimens were found at 500-700 meters while at night, most were found at 300-400 meters.[11]

H. heteropsis live in the Pacific Ocean and are predominantly found in the California Current and the Humboldt Current.[4] Population distribution of H. heteropsis is better known in the California Current than it is in the Humboldt Current and the species does not inhabit waters close to the equator.[4] There is no evidence to suggest horizontal migration in histioteuthid squids, including H. heteropsis.[4]

Within marine food webs, H. heteropsis plays an important role in the diets of tuna, porpoises, blue sharks, sperm whales, elephant seals, and albatross.[4] Not much is known about the diet of H. heteropsis itself, although limited stomach content evaluations show that they feed on fish, crustaceans, and smaller squids.[4]

Behavior

Feeding

H. heteropsis searches for prey using visual clues and strikes forward at the prey using their tentacles.[9] The tentacles then bring the prey within range of the arms, which hold the prey in place with suckers.[9] H. heteropsis, like most squids, bite immediately into the fleshy parts of the prey with their beak and release the leftover corpse.[9]

Mating

Very little is known about mating and courtship in H. heteropsis, although it is likely that these behaviors occur in deeper waters.[4] Spawning may occur in deep-midwater or near-surface waters, but it is still unclear.[4]

Inking

Inking developed as an important protective mechanism for coleoid cephalopods after losing their ancestral external shell.[5] However, inking is metabolically costly since it requires the discharge of both melanin and mucus.[5] Because of this, H. heteropsis typically only inks when approached closely or touched.[5] Researchers Stephanie Bush and Bruce Robinson observed that H. heteropsis most often produces an ink cloud categorized as "pseudomorphs", which are "dense blobs of ink the approximate shape and size of the individual releasing them."[5] In all instances of inking, H. heteropsis specimens lingered in the ink cloud unless further provoked.[5]

Taxonomy

In 1913, Berry discovered H. heteropsis and recognized it as a member of the family Histioteuthidae due to its large number of photophores.[7] Based on significant morphological traits, it appears that H. heteropsis is most closely related to H. meleagroteuthis and H. bonnellii.[7]

Conservation status

Based on a 2010 assessment by the International Union for Conservation of Nature (IUCN), H. heteropsis is categorized as least concern due to its large geographic distribution.[12] There are no known threats to the species and population information is not available.[12] The IUCN recommends that more research be done into H. heteropsis to determine details about its population and ecological role.[12]

References

  1. ^ Barratt, I.; Allcock, L. (2014). "Histioteuthis heteropsis". IUCN Red List of Threatened Species. 2014: e.T162925A953880. doi:10.2305/IUCN.UK.2014-1.RLTS.T162925A953880.en. Retrieved 18 November 2021.
  2. ^ a b "Multimedia Gallery - Cockeyed squid (Histioteuthis heteropsis) | NSF - National Science Foundation". www.nsf.gov. Retrieved 2020-07-22.
  3. ^ a b c d e f g h i Thomas, Kate N.; Robison, Bruce H.; Johnsen, Sönke (2017-04-05). "Two eyes for two purposes: in situ evidence for asymmetric vision in the cockeyed squids Histioteuthis heteropsis and Stigmatoteuthis dofleini". Phil. Trans. R. Soc. B. 372 (1717): 20160069. doi:10.1098/rstb.2016.0069. ISSN 0962-8436. PMC 5312019. PMID 28193814.
  4. ^ a b c d e f g h i j k l Voss, N. A.; Sweeney, M. J. (1998). "Systematics and Biogeography of cephalopods. Volume II". Smithsonian Contributions to Zoology (586): 277–599. doi:10.5479/si.00810282.586.277. ISSN 0081-0282.
  5. ^ a b c d e f Bush, Stephanie L.; Robison, Bruce H. (2007-06-26). "Ink utilization by mesopelagic squid". Marine Biology. 152 (3): 485–494. doi:10.1007/s00227-007-0684-2. ISSN 0025-3162. S2CID 84629175.
  6. ^ "We have a new visitor from the deep in our Tentacles special exhibition: the cock-eyed squid!". MBA Tumblr. Monterey Bay Aquarium. June 27, 2014. Retrieved March 29, 2016.
  7. ^ a b c d e f Voss, Nancy A. (1969). "Biological investigations of the deep sea. 47. A monograph of the Cephalopoda of the North Atlantic. The family Histioteuthidae". Bulletin of Marine Science. 19 (4): 713–867 – via Ingenta Connect.
  8. ^ a b c d Young, Richard Edward (1983). "Oceanic bioluminescence: an overview of general functions". Bulletin of Marine Science. 33 (4): 829–845 – via Ingenta Connect.
  9. ^ a b c d Barord, Gregory Jeff; Boyle, P. (2019), "Cephalopods", Encyclopedia of Ocean Sciences, Elsevier, pp. 516–522, doi:10.1016/b978-0-12-409548-9.11604-5, ISBN 978-0-12-813082-7
  10. ^ Laptikhovsky, Vladimir (2001-06-30). "First data on ovary maturation and fecundity in the squid family Histioteuthidae". Scientia Marina. 65 (2): 127–129. doi:10.3989/scimar.2001.65n2127. ISSN 1886-8134.
  11. ^ a b Roper, Clyde F. E.; Young, R. E. (1975). "Vertical distribution of pelagic cephalopods" (PDF). Smithsonian Contributions to Zoology (209): 1–51. doi:10.5479/si.00810282.209. ISSN 0081-0282.
  12. ^ a b c Barratt (SRLI), Iain; Allcock (SRLI), Louise (2010-05-05). "IUCN Red List of Threatened Species: Histioteuthis heteropsis". IUCN Red List of Threatened Species. doi:10.2305/iucn.uk.2014-1.rlts.t162925a953880.en. Retrieved April 10, 2023.
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Histioteuthis heteropsis: Brief Summary

provided by wikipedia EN

Histioteuthis heteropsis (H. heteropsis), also known as the strawberry squid, is a species of small cock-eyed squid. The scientific nomenclature of these squid stems from their set of differently sized eyes, one being small and blue and the other being large and yellow. It is thought that the large eye is used to see objects against dim light, while the smaller eye is more able to view bioluminescent light sources. The squid's vernacular name arose due to its rich red skin pigmentation and the presence of photophores along its body, making it appear like a strawberry with seeds.

H. heteropsis live in the ocean's mesopelagic zone and are found in the California Current and the Humboldt Current. Little is known about their specific feeding and mating behaviors, although their inking patterns have been subject to study. They are not easily disturbed, and only ink when provoked.

H. heteropsis was discovered by Berry in 1913 and exhibited publicly for the first time at the Monterey Bay Aquarium on June 27, 2014.

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Habitat

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mesopelagic

Reference

van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO).

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Jacob van der Land [email]