Family VAMPYROTEUTHIDAE

Museums

Museum list

Regional Maps

Family VAMPYROTEUTHIDAE

Compiler and date details

July 2001 - C.C. Lu, National Chung Hsing University, Taichung, Taiwan

Introduction

The monotypic family Vampyroteuthidae Thiele, 1915 is easily recognised by the jet black gelatinous body, the presence of a single pair of fins and of a pair of retractile, sensory filaments in addition to the eight sessile arms. The suckers are arranged in a single row and alternate with lateral cirri along most of the arm.

Vampyroteuthis infernalis, the sole member of the family, was described by Chun based on a specimen taken by the German Valdivia Expedition in the Guinea Basin, South Atlantic (Chun 1903). Subsequently, the species has been taken in the Pacific Ocean and the Indian Ocean (Berry 1911, 1912; Massy 1916; Sasaki 1920, 1929; R.E. Young 1972) and elsewhere in the Atlantic Ocean (Joubin 1912, 1920, 1929, 1937). The family was erected by Thiele in 1915 and was originally regarded as an octopod. In 1939, Pickford transferred it to a new order of its own, the Vampyromorpha. The species has been studied and reported on extensively by Pickford (1939a, 1939b, 1940, 1946, 1949a, 1950, 1952, 1959). Her reports on the natural history and distribution (Pickford 1946) and the external anatomy (Pickford 1949a) remain the most comprehensive monographs on the species.

The first Australian records of Vampyroteuthis infernalis are of two specimens taken during the Dana Expedition in 1929, and listed by Pickford (1946). The species was reported from off south-eastern Tasmania by Lu & Phillips (1985).

Vampyroteuthis infernalis has the arms connected by deep webs. It also has a pair of unique, slender filaments, extending from a pair of pockets on the dorsal surface of the web between the dorsal and dorso-lateral arms. Each filament is retractile and often completely retracted within the pocket. The filaments were considered originally to be homologous with arms (Pickford 1940), but from studies on their innervation, R.E. Young (1967) concluded that the filaments are not homologous with the arms. Nonetheless, J.Z. Young (1977) still considered the filaments to be the modified second pair of arms of a decapod. The true origin of the filaments remains unclear.

The vampyromorph has a shell-sac running from the neck backwards to the apex of the body where it bends towards the ventral surface. The shell, located within the shell-sac, is a thin, plate-like, transparent, non-calcified structure. There is a little cup-shaped conus, but no trace of a chambered phragmocone. No significant sexual differences in the shape and structure of the shell are apparent. The larval shell is more slender than that of adults. The function of the vampyromorph shell is unknown (Pickford 1949a).

Vampyroteuthis infernalis has many photophores scattered over the surface of the head, mantle, fins and arms, particularly on the ventral surface of the animal, but none on the web area or the oral surface of the arms. A single large photophore is present posterior to each fin. An oval patch of thickly packed small photophores is located on the dorso-lateral surface of the mantle at the level of the mantle opening.

The vampyromorph mantle musculature, particularly the circular muscle, is poorly developed; the bundles of radial muscle fibres are interspersed with gelatinous mass. The methods of swimming in Vampyroteuthis are (1) moderate swimming with arms pointed forward in the direction of motion, propulsion provided by the fins; (2) rapid swimming with a medusoid action of the arms and web; and (3) slow swimming with water ejected through the funnel, the fins spread as stabilisers (Young in Roper & Brundage 1972). Young also stated that the first is the primary method, the second method is rarely used, and the third method needs verification. The propulsion provided by the fins in the first method is produced by a well-developed muscular band attached to the pen in the anterior margin of the fins (Clarke 1988).

J.Z. Young (1977) reported the presence of plankton, including diatoms and copepods in the crop of a specimen of Vampyroteuthis infernalis and suggested that the species feeds by collecting small organisms.

Little is known about the reproductive biology of Vampyromorpha; Pickford’s (1946, 1949a, 1949b, 1959) works are the main source of information. Some sexual dimorphism is evident, the females being larger than the males. The males lack a hectocotylus. The single penis lies on the left side of the visceral mass and projects freely into the mantle cavity. In adult males, the penis lies inside the funnel which is probably used to transfer spermatophores into the females’ seminal receptacles. The spermatophores are about 20 mm long. Females lack nidamental glands, but a well-developed oviducal gland is present at the end of each oviduct; a pouch-like seminal receptacle occurs in front of each eye. The eggs are spherical, about 3.5 mm in diameter; they are devoid of any jelly and are pelagic. Nothing is known about embryonic development in Vampyroteuthis.

Pickford (1946, 1959) reported that larvae of Vampyroteuthis have been captured in all seasons of the year, the sexually mature adults taken in various months from August to January in different oceans. Eggs in the gonad range widely in size, suggestive of an absence of reproductive seasonality (R.E. Young in Arnold & Williams-Arnold 1977).

Larval fins of Vampyroteuthis undergo a notable metamorphosis. Pickford (1946) divided the development into five stages: in the first, only a pair of larval fins are present; in the second, the early four-finned stage, the adult fins do not exceed 60% of the length of the larval fins; in the third, the four-finned stage, the larval and adult fins are subequal in size; in the fourth, the late four-finned stage, the adult fins are markedly larger and the larval fins do not exceed 60% of adult fins; and in the fifth stage, only a pair of adult fins are present with the larval fins represented by mere rudiments.

Vampyromorphs are stenothermic and stenohaline. The majority of specimens studied by Pickford (1946) were taken from waters between 2.0° and 5.9°C and salinities of 34.70‰ to 34.99‰. Furthermore, vampyromorphs appear to prefer waters that are relatively poor in oxygen (below oxygen minimum). Pickford (1946) also reported that water density is a common factor delimiting the water layers inhabited by Vampyroteuthis. The majority of specimens have been taken in layers between sigma t = 27.4 and 27.8.

Vampyroteuthids have been reported from the stomach contents of the pygmy sperm whale, Kogia breviceps, and the dwarf sperm whale, K. simus, from South African waters and the northern bottlenosed whale, Hyperodon ampullatus, of Denmark (Clarke 1986).

Vampyroteuthis infernalis is a cosmopolitan species, distributed in all three major oceans, from the tropical to the temperate latitudes; it is absent from the Mediterranean Sea. Data from opening-closing net captures reveal that the species inhabits the lower mesopelagic to bathypelagic zones from 500–1500 m with the peak of distribution being at depths of 800–900 m in the North Atlantic (Lu & Clarke 1975). Off California, the centre of vertical distribution is 500–1200 m with the peak at 700–800 m (Roper & Young 1975). No diel migration is apparent in adults (Lu & Clarke 1975), but young less than 20 mm ML generally live in water deeper than 900 m while the adults and subadults live primarily at depths less than 900 m; the young undergo ontogenetic ascent when the larval fins are resorbed (Roper & Young 1975).

In Australian waters, the majority of captures have been from off the east coast from Cape York (11°46'S 145°E) to south-east of Tasmania (44°S 150°E) with one specimen taken from the Great Australian Bight (34°40'S 120°25'E) (Pickford 1946; Lu 2001). No specimens have been taken on the west coast of Australia, but this may simply reflect paucity of sampling.

Diagnosis

This monotypic family is characterised by the presence of a single pair of fins, and a pair of retractile, sensory filaments in addition to the eight sessile arms. The arms are connected by a deep web which extends to about 2/3 of arm length. On the oral surface of the arms a single row of suckers alternates with paired cirri along most of the arm length. The mantle is fused to the head and the mantle opening is wide. Photophores are present.