Normanina, CUSHMAN, 1928

Gooday, Andrew J., Kamenskaya, Olga E. & Cedhagen, Tomas, 2007, New and little-known Komokiacea (Foraminifera) from the bathyal and abyssal Weddell Sea and adjacent areas, Zoological Journal of the Linnean Society 151 (2), pp. 219-251 : 240-244

NORMANINA CUSHMAN, 1928

Type species: Halyphysema conferta Norman, 1878

NORMANINA CONFERTA ( NORMAN, 1878)

( FIGS 14A–D , 15A, B )

Halyphysema conferta Norman, 1878, p. 279 , pl. 16, figs 1, 2

Normanina conferta (Norman) . Cushman, 1928, p. 7

Normanina conferta (Norman) . Loeblich & Tappan, 1964, C192, fig. 108.8a

Normanina conferta (Norman) . Schröder, Medioli & Scott, 1989, p. 30; pl. 1, fig. 5, text-fig. 9

Normanina conferta (Norman) . Shires, 1995, p. 65, pl. 3.4, fig. 5

Normanina tylota Tendal & Hessler, 1977, p. 182 ; textfigs 5, 6; pl. 11, fig. E, F; pl. 12, figs C, D, F; pl. 19, fig. B; pl. 22, fig. A, B

Normanina conferta (Norman) . Loeblich & Tappan, 1987, p. 41, pl. 30, figs 4, 5

Normanina tylota Tendal & Hessler, 1977 . Gooday, 1994, fig. 1, fig. h

Diagnosis. Test approximately spherical in overall form, typically up to 1–1.7 mm in diameter, fragile, consisting of variable number of unbranched, radiating tubules, each bearing club-shaped to irregular swelling, subdivided internally by septa. Between these tubules with swellings, there radiate a smaller number of simple, easily broken, unbranched tubules, which may reach lengths up to several times the diameter of the main part of the test.

Syntype of Halyphysema conferta . A specimen labelled ‘lectotype’, collected in August 1875 from Valorous Stn 9, 59°10′N, 50°25′W, 1750 fm = 3027 m water depth, south of Greenland. Natural History Museum, London, reg. no ZF 3657; mounted dry on a cardboard slide. The writing on the slide indicates that this is the specimen illustrated by Norman (1878) and by Loeblich & Tappan (1964, 1987). The illustration of Loeblich & Tappan has features in common with Norman’s original figure but not with the specimen as it now appears (compare Loeblich & Tappan, 1964: fig. 108a with our Fig. 14A, B ). However, Norman (1878) found only two examples of this species and one of them was devoid of club-like swellings. Loeblich and Tappan’s ‘holotype’ must be the specimen that we examined but it has clearly been damaged and lost many of its tubules and swellings. The specimen is a figured syntype, not a holotype or lectotype ( Adams, Harrison & Hodgkinson, 1980).

Type specimen of Normanina tylota . Argo H-30, central North Pacific , epibenthic sledge sample: 30°05′N, 156°12′W; 6065–6079 m water depth. Zoological Museum, Copenhagen; preserved in alcohol .

ANDEEP material: Stn 21#5, 1 specimen; Stn 59#9, 1 specimen; Stn 78#9, 1 specimen; Stn 80#9, 1 specimen; Stn 81#8, 14 specimens; Stn 88#5, 8 specimens; Stn 88#7, 7 specimens; Stn 88#8, 38 specimens; Stn 88#9, 2 specimens; Stn 94#5, 3 specimens; Stn 94#7, 1 specimen; Stn 94#11, 1 specimen; Stn 94#14, 12 specimens; Stn 102#8, 4 specimens; Stn 102#11, 6 specimens; Stn 102#13, 22 specimens; Stn 110#8, 65 specimens; Stn 121#7, 1 specimen; Stn 133#2, 1 specimen.

Description of Halyphysema conferta syntype

The test forms a rather compact brownish mass, measuring 1.1 × 0.75 mm ( Fig. 14A, B ). It is incomplete and the tubules and terminal swellings are intact only on one side of the test. Comparison with illustrations of the same specimen by Norman (1878) and Loeblich & Tappan (1964, 1987) suggest that the tubules have been broken off around most of the test periphery. The surviving tubules are rather thick (30–40 µm) and the terminal swellings 120–230 µm wide and 140–215 µm long. The wall incorporates tiny sediment grains that can be resolved under a lowpower dissecting microscope, set in a matrix of finer material. Because the specimen is dried and mounted on an opaque background, nothing can be seen of its internal structure.

Description of Normanina tylota holotype

The type specimen, preserved in alcohol, measures 1.53 × 0.82 mm and is rather compressed as a result of having been confined within a small vial ( Fig. 14C, D ). It has lost some of the swellings and the two long tubules shown in Tendal & Hessler’s (1977: fig. 5) illustration. The tubules are 20–30 µm in diameter and the bulb-like swellings measure 240–330 µm in maximum dimension. Two bulbs arising from different tubules have fused together, a feature sometimes seen in ANDEEP specimens. The test is brownish in colour and the wall is composed of fine-grained particles, some of which glint in reflected light.

Description of ANDEEP material

Forty-five individuals from Stns 88 and 94 range in diameter (excluding long tubules) from 0.90 to 2.0 mm; most (35 individuals) are between 1.25 and 1.65 mm diameter. The test is whitish in colour. Relatively short tubules, 25–50 µm (typically 35–40 µm) in diameter, radiate from the central region and end in bulb-like swellings up to 350 µm (typically 150– 250 µm) in diameter. These range from simple oval swellings to more complex, sometimes bilobed structures. There is considerable variation in the number of tubules that end in swellings. In some individuals they are sparsely developed, numbering ten or fewer; in others from the same sample, they are more numerous. However, specimens from Stn 88 ( Fig. 15A ) tend to have sparser tubules than those from Stn 102 ( Fig. 15B ). A single individual from the Anguilas Basin (Stn 21) has numerous terminal swellings arising from an extensively branched tubule system, but nevertheless falls within the range of variation exhibited by the Weddell Sea material.

The central part of the test is entirely devoid of sediment in all ANDEEP specimens. It is occupied by tubules that branch frequently, apparently dichotomously, and occasionally anastomose. The complexity of this inner region varies considerably, from having relatively few branches to being a tightly structured mass of tubules. Arising from the inner part of the test are longer, unbranched tubules that extend for a sometimes considerable distance beyond the main part of the test. In the ANDEEP material, the longest of these tubules measures 2400 µm from its base. Others are up to 1600 µm in length but most are much shorter and possibly broken. They are often narrower (∼25 µm) than the other tubules and never end in a distal swelling.

The test wall is finely granular but also incorporates some larger grains. A few large mineral grains (usually quartz but sometimes dark minerals) up to 200–300 µm in diameter, or (at Stn 21) fragments of globigerinacean shells, are sometimes present. The swellings and tubules of the Stn 21 specimen have a darker filling than those from other sites.

Remarks

We follow Schröder et al. (1989) in identifying this species as Normanina conferta . Our extensive material is closely similar to Schröder et al.’s (1989) figured specimens from the Nares Abyssal Plain. In both cases, the inner part of the test is devoid of sediment. The syntype of N. conferta in the Natural History Museum, London, appears more compact than the ANDEEP specimens and lacks the long, unbranched tubules. This probably reflects the dried and damaged condition of the specimen. Nevertheless, the diameters of the tubules in the syntype are similar, and the shape of the swellings falls within the range of variation observed in ANDEEP specimens.

Based on a re-examination of the type specimens, we consider N. conferta to be conspecific with N. tylota . Tendal & Hessler (1977) acknowledged the close relationship between the two species but distinguished them based on the presence in N. tylota of two types of tubules and the large variation in the shape of the swellings. As indicated above, the long tubules may be missing because of damage in the syntype of N. conferta and the surviving swellings in this specimen exhibit some variation in shape.

One notable difference between the ANDEEP specimens and the types of both N. conferta and N. tylota is the absence of any sediment in the central region of the test. Typical Weddell Sea specimens are also pure white in colour compared with the brownish appearance of N. tylota and the dirty grey colour of the N. conferta syntype (possibly due to the age of the dried specimen). The ANDEEP material exhibits considerable variation in the number of tubules, even within the same sample ( Fig. 15 ). To some extent, this variation mirrors the ‘compact’ and ‘spidery’ morphotypes of Septuma ocotillo .

Distribution

Normanina conferta was first described from the Davis Strait, off Greenland (3202 m water depth) ( Norman, 1878), and subsequently reported from the Nares Abyssal Plain (∼ 5775 m) ( Schröder et al., 1989). Normanina tylota was described from the abyssal central North Pacific ( Tendal & Hessler, 1977) and later reported from the Porcupine Abyssal Plain (4841 m) ( Gooday, 1994; Shires, 1995). In our material this species occurs in the Anguillas Basin (4566 m), eastern Weddell Sea, slope and abyssal plain (2147– 4649 m water depth), central abyssal Weddell Sea (4695–4934 m), and north-east Peninsula slope (1579–2620 m).

NORMANINA SP.

( FIG. 14E, F )

Material examined: A single individual from Stn 142#5, Epibenthic sledge.

Description

The specimen, which appears to be somewhat distorted, measures 2.1 × 1.3 mm. One side consists of a tangle of branching tubules, partly obscured by sediment. This part forms a kind of base from which other, longer tubules arise. These tubules are 45–70 µm wide and branch dichotomously. Many of the branches end blindly but some terminate in bulbous swellings. In total, there are ∼12 of these swellings, measuring 280–380 µm in maximum diameter and oval to lobate in shape; a few other tubules end in much smaller swellings, 90–100 µm in diameter. Long, unbranched tubules are not present, although one tubule, which branches several times but lacks swellings, extends further than the others from the main part of the test. The tubules have finely agglutinated, translucent walls. The walls of the bulbs are thicker and opaque. In both cases, larger grains are absent.

Remarks

This single individual is larger and more robust than the common ANDEEP form of Normanina conferta . The tubules are also wider, branch more frequently and often end blindly rather than being expanded into swellings. The swellings themselves tend to be larger than in N. conferta . Also, long, unbranched tubules are absent, and some sediment is present between the tubule interstices. This form also differs from the type specimens of N. tylota and N. conferta in many of the above-mentioned features, although it resembles them in having some interstitial sediment. It probably represents an undescribed species.

Distribution

Powell Basin (2404–3408 m).

Figures

Figure 14. A–D, Type specimens of Normanina species. A, B, Damaged syntype of Haliphysema confertum Norman, 1878, Natural History Museum, London, reg. no. ZF3657, confocal light photographs showing entire specimen (A) and detail of tubules and terminal swellings (B); C, holotype of Normanina tylota Tendal & Hessler, Zoological Museum, Copenhagen, photographed in alcohol using combination of reflected and transmitted light; D, opposite side of same specimen, transmitted light. E, F, Normanina sp. from Stn 142#5. E, general view by reflected light; F, different view using combination of reflected and transmitted light.

Figure 15. Normanina conferta (Norman, 1878). Specimens photographed in water using transmitted light. A, Stn 88#8; B, Stn 102#13.