T A N E 26, 1980

N E W R E C O R D S O F W A R M - W A T E R F O R A M I N I F E R A F R O M N O R T H - E A S T E R N N E W Z E A L A N D .

by Bruce W . Hayward New Zealand Geological Survey, P.O. Box 30-368, Lower Hutt

S U M M A R Y

Six species of warm-water benthic foraminifera (Spiroloculina angulata, Wiesnerella auriculata, Amphistegina papillosa, Carterina spiculotesta, Loxostomum limbatum costulatum and Sigmavirgulina tortuosa) found in surface sediments around the Caval l i Islands, east Northland, are recorded from New Zealand for the first time. These are also the first records in the New Zealand Recent fauna of the genera Wiesnerella, Amphistegina, Carterina and Sigmavirgulina.

These taxa, together wi th a number of other warm-water foraminifera previously recorded from north-eastern New Zealand, are believed to have arrived here since the L a s t Glaciation, being carried south in warm currents.

I N T R O D U C T I O N

Recent studies on the benthic foraminifera around the Caval l i Islands have produced a number of records of taxa not previously known from New Zealand. The Caval l i Islands (latitude 35° 00' S, longitude 173° 57' E) he 2—4 k m off the east coast of Northland midway between the B a y of Islands and Whangaroa Harbour (Harward 1979a). The foraminifera studied are from 55 dredge samples of surface sediments taken at 0 to 41 m during the Offshore Islands Research Group trip at New Year 1978-1979 (Hayward 1979b, Grace & H a y w a r d 1980). " L i v e " individuals were distinguished using the protoplasm stain, Rose Bengal.

M a n y of the new records are of taxa whose distribution is not well known. In this note only taxa of undoubted warm-water distribution are dealt with. I have endeavoured to compliment the Caval l i Island records of these species by l ist ing other samples held by the New Zealand Geological Survey in which they occur.

Sample numbers (e.g. F201 720) quoted are those of the New Zealand Geological Survey, Micropaleontology Section, Lower H u t t .

N E W R E C O R D S

Spiroloculina angulata Cushman F i g . 2 Spiroloculina grata var. angulata Cushman 1917, U.S. National

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Museum Bulletin 71: 36, p i . 7, fig. 5. New Zealand Localities: Caval l i Islands - 6 m, 40 m, 41 m (F201 719, 720, 729); H e n and Chicken Islands - 60 m, 85 m (F201 048, 050); Goat Island B a y - beach (F201 352); Whangateau Harbour entrance - beach (F201 353). N o live individuals observed. Distr ibut ion: Widely distributed in the tropical and sub-tropical Indo-Pacific and Mediterranean. The nearest records to New Zealand are from New South Wales, F i j i , Tonga (Cushman and Todd 1944) and Norfolk Island (F201 573). New Zealand Localities: Caval l i Islands - 6 m, 40 m, 41 m (F201 719, 720, 729); H e n and Chicken Islands - 60 m, 85 m (F201 048, 050); Goat Island B a y - beach (F201 352); Whangateau Harbour entrance - beach (F201 353). N o live individuals observed. Distr ibut ion: Widely distributed in the tropical and sub-tropical Indo-Pacific and Mediterranean. The nearest records to New Zealand are from New South Wales, F i j i , Tonga (Cushman and Todd 1944) and Norfolk Island (F201 573).

Wiesnerella auriculata (Egger) F i g . 1. Planispirina auriculata Egger 1893, K. Bayer. Akademie der

Wissenschaften, Mathematisch-Physikalische 18 (2): 245, p i . 3, figs. 13-15. New Zealand Local i t ies :Caval l i Islands - 10 m, 36 m, 40 m (F201 718, 719, 752). N o live individuals seen. Distr ibut ion: This relatively rare species is widely distributed throughout the warmer seas of the world. New Zealand Foss i l Record: This species is known from the lower Miocene, A l ton ian stage and the genus is also known from the Eocene, Runangan stage (Hornibrook 1961).

Amphistegina papillosa Said F i g . 4. Amphistegina radiata var. papillosa Said, 1949, Cushman

Laboratory for Forminiferal Research, Special Publication 26: 39, p i . 4, fig. 12. New Zealand Local i ty : Caval l i Islands -1.5 m (F201 756). Distr ibut ion: Amphistegina is a tropical to warm subtropical genus, w i th its range apparently l imited by the 14°C winter isotherm (Larsen 1976). I consider this value to be rather liberal and 16°C to be more accurate. Amphistegina's extreme latitudinal l imits are 34°N, off south-east Japan and 37°S, off eastern Aust ra l ia (Todd 1978). New Zealand Foss i l Record: A. papillosa has not been recorded in New Zealand, but the genus is extremely abundant in Eocene to mid Miocene rocks. There are also scattered records of Amphistegina from the late Miocene and Pliocene, but i t is not known from our Pleistocene (Hornibrook 1968).

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Figs 1 - 7. Scanning electron photographs of Recent foraminifera from the Cavalli Islands. (Numbers prefixed by F P are NZ Geological Survey catalogue numbers). 1. Wiesnerella auriculata, length 0.47 mm, F P 2981; 2. Spiroculina angulata, length 0.48 mm, F P 2982; 3. Loxostomum limbatum costulatum, length 0.45 mm, F P 2983; 4. Amphistegina papillosa, diameter 1.2 mm, F P 2984; 5. Sigmavirgulina tortuosa, length 0.40 mm, F P 2985; 6. Carterina spiculotesta, juvenile, greatest diameter 0.8 mm, F P 2986; 7. Carterina spiculotesta, average length of spicules 0.05 mm, F P 2986.

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Discussion: The Caval l i Islands' record is of a single, somewhat worn, adult specimen (Fig. 4) which was dead at the time of collection. Amphistegina are large, robust foraminifera, prone to reworking from older sedimentary rocks and therefore the possibil ity that this specimen is derived from older rocks must be considered. The abraded character of the specimen might be taken as indicative of reworking, but many of the foraminifera in the coarse bioclastic sediments around the Cavall is are abraded and obviously not reworked. There are no older marine sedimentary rocks exposed on land wi th in tens of kilometres of the Caval l is from which Amphistegina could be derived, although the possible presence of a submarine outcrop of Pleistocene rocks cannot be discounted. Further support for m y contended Recent age for this Amphistegina comes from the lack of any obviously reworked foraminifera around the Caval l is , the absence of this species in our fossil record, its abundance in Recent sediments around Norfolk Island and the presence of other warm-water taxa in Caval l i Island's sediments.

Carterina spiculotesta (Carter) F igs . 6, 7. Rotalia spiculotesta Carter 1877, Annals and Magazine of Natural

History 20:470, p i . 16, figs. 1-3. New Zealand Localities: Cava l l i Islands - 2.5 m, 3 m, 8 m, 33 m (F201 750, 755, 758, 766), a l l " a l i ve " ; Mokohinau Islands - 24 m (F. Brook collection). Distribution : Indo-Pacific and Mediterranean tropical to sub-tropical shallow water. Discussion: This monotypic genus is unique in that i t produces its own calcareous fusiform spicules (Fig. 7) to bui ld its test.

Loxostomum limbatum costulatum (Cushman) F i g . 3. Bolivina limbata var. costulata Cushman 1922, Carnegie Institute

Publication 311: 26, p i . 3, fig. 8. New Zealand Localities: Caval l i Islands - 3 m, 5.5 m, 9 m (F201 746, 757, 758); Goat Island B a y - beach (F201 352); K a w a u Island - 10 m (F201 817). N o live individuals seen. Distribution: Widely distributed in the shallow tropical to sub-tropical waters of the world, w i th many records from the Indo-Pacific and Caribbean. The nearest records to New Zealand are from the Great Barrier Reef and Samoa (Cushman 1937).

Sigmavirgulina tortuosa (Brady) Bolivina tortuosa (Brady 1881, Quarterly Journal of Microscopical

Science 21: 57. New Zealand Localities: Caval l i Islands - beach, 2.5 m, 3 m, 10 m, 34 m (F201 721, 725, 732, 736, 755, 760); Goat Island B a y - beach (F201

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352); K a w a u Island -10 m (F201 817); Whangateau Harbour entrance -beach (F201 353). Some live individuals. Distr ibut ion : A common species in warm, shallow water of Indo-Pacific and Caribbean. The nearest records to New Zealand are from New South Wales, F i j i , Tonga and L o r d Howe Island (Cushman 1937). New Zealand Foss i l Record: This species occurs commonly in Oligocene and lower Miocene rocks (Whaingaroan to A l ton ian stages).

D I S C U S S I O N

In New Zealand these six species are only known from shallow locations off the east coast of Northland. This distribution is similar to that of a number of other warm-water foraminifera previously recorded from New Zealand (e.g. Buliminoides williamsoniana, Cornuspirella diffusa, Cornuspiroides foliaceus — Eade 1967), and to that of several other previously unrecorded species that are possibly warm-water restricted (e.g. Neoconorbina pacifica, Rugidia simplex, Suratkina australiensis).

This distribution pattern parallels that of a number of higher animal groups (e.g. mollusca, echinoderms, fish), and appears to be related to the warm E a s t A u c k l a n d Current (Brodie 1960). A l l are probably derived from warmer waters, either from the north-west (Lord Howe and Norfolk Islands) v ia the E a s t Austra l ian Current or from the north-east (Kermadec Islands) v ia the Trade W i n d Dr i f t , and then carried southwards offshore along the coast of Northland. This warm E a s t Auck land Current comes close inshore in only a few places and the Caval l i Islands are one of these, although ly ing on the fringe of the current.

Amphistegina and Carterina are the two most tropical taxa of these six new records. It is significant that only one specimen (Fig. 4) of Amphistegina was found at the Caval l i Islands and it seems unlikely that this taxon is breeding here. It may however have a breeding population in a suitable habitat further out in the current, such as at Cape K a r i k a r i or Poor Knights Islands. The distr ibution of Amphistegina appears to be l imited by the 16°C winter isotherm and this is very close to the winter temperature of 15°C of the E a s t A u c k l a n d Current (R.V. Grace pers. comm.).

Only juvenile specimens of Carterina were found at the Caval l i Islands but an adult was found at the Mokohinau Islands, further out in the warm current. This taxon could easily have a breeding population somewhere off eastern Northland.

Spiroloculina angulata, Sigmavirgulina tortuosa and Loxostomum limbatum costulatum are more common around the Caval l i Islands than Amphistegina, Carterina and Wiesnerella. A l l are undoubtedly breeding in New Zealand waters and a l l are also found in the Cape

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Rodney area, 150 k m south of the Cavall is , which is sometimes affected by the E a s t A u c k l a n d Current.

It is interesting to note that Amphistegina, Sigmavirgulina and Wiesnerella were a l l present in the New Zealand region in the middle Tert iary when surface water temperatures were warmer than they are today. A l l disappear from the fossil record in the late Tertiary, as temperatures dropped. A l though it is not possible to determine whether they disappeared completely from New Zealand due to the lack of late Tert iary marine rocks in Northland, i t is unlikely that they survived the Pleistocene glacial periods. It seems most probable that the present records are a result of reinvasion of New Zealand since the L a s t Glaciation by taxa carried down from the north.

A C K N O W L E D G E M E N T S

I am grateful to Fred Brook for the use of his Mokohinau Island record of Carterina spiculotesta, and to Anthony Edwards, Norcott Hornibrook and Robert Hoskins for reading the manuscript and suggesting improvements.

R E F E R E N C E S

Brodie, J.W. 1960: Coastal surface currents around New Zealand. N.Z. Journal of Geology and Geophysics 3: 235-252.

Cushman, J .A . 1937: A monograph of the subfamily Virgulininae of the foraminiferal family Buliminidae. Cushman Laboratory for Foraminiferal Research, Special Publication No. ft 228 p.

Cushman, J .A . & Todd, R. 1944 : The genus Spiroloculina and its species. Cushman Laboratory for Foraminiferal Research, Special Publication No. 11. 82 p.

Eade, J.V. 1967: A checklist of Recent New Zealand foraminifera. N.Z. Oceanographic Institute Memoir 44. 72 p.

Grace, R.V. & Hayward, B.W. 1980: The macrobenthos of the Cavalli Islands, north­eastern New Zealand. Tane 26: (this issue).

Hayward, B.W. 1979a: Cavalli Islands trip, New Year 1978-1979. Introduction and Acknowledgements. Tane 25:35-40.

Hayward, B.W. 1979b: Planktic foraminifera in surface sediments around the Cavalli Islands, northern New Zealand. Tane 25:149 -155.

Hornibrook. N. deB. 1961: Tertiary foraminifera from Oamaru district. New Zealand Geological Survey, Paleontological Bulletin 34, 192 p.

Hornibrook. N. deB. 1968: Distribution of some warm water benthic foraminifera in the N.Z. Tertiary. Tuatara 16:11 -15.

Larsen, A.R. 1976: Studies of Recent Amphistegina, taxonomy and some ecological aspects. Israel Journal of Earth Sciences 25:1 - 26.

Todd, R. 1976: Some observations about Amphistegina (foraminifera). "Progress in Micropaleontology", Special Publication, American Museum of Natural History : 382 - 394.

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