Diatoms from brittle star stomach contents: Implications for sediment ...
Table 2. Developmental times (In days) for larvae of Euphausla
superba
Investigators
Stage
Present McWhinnie & Denys Witek et al. study (1978) (1980) (USARP 82)
3-4 N.D.a 5-6 Egg to nauplius I Egg to nauplius II 7-8 N.D. 8-10 Egg to metanauplius 10-18 N.D. 15-18 Egg to calyptopis I N.D. 30 21-25 Egg to calyptopis II N.D. 45. 50, 60 b 32-37 "N.D. = no data. b Field estimates based on first, middle, and last time of spawning to first, middle, and last appearance of calyptopis II in the plankton.
Figure 2. Naupiii hatching from eggs released by Euphausla superba at Palmer Station during USARP 82. (Photo by L. B. Quetln)
port of our research efforts. This research was supported by National Science Foundation grant DPP 80-20739.
References March went on to hatch (figure 2). Usually, either all the eggs hatched or none hatched. We found developmental times for the naupliar stages comparable to those that McWhinnie and Denys (1978) found. Laboratory estimates of developmental times for the calyptopis stages, however, appear to be shorter than field estimates (Witek, Koronkiewicz, and Soszka 1980) (table 2). Newly hatched larvae must reach the surface in 21-25 days, if surface food sources are vital to their development at the first feeding stage (calyptopis 1). We thank Captain P. Lenie, the crew of the RJv Hero, and the support personnel at Palmer Station for their outstanding sup-
Diatoms from brittle star stomach contents: Implications for sediment reworking DAVIDA E. KELLOGG and THOMAS B. KELLOGG
Department of Geological Sciences
and Institute for Quaternary Studies University of Maine at Orono Orono, Maine 04469 JOHN H. DEARBORN, KELLY C. EDWARDS, and DAVID B. FRATT
Department of Zoology University of Maine at Orono Orono, Maine 04469
1982 REVIEW
El-Sayed, S., and McWhinnie, M. A. 1979. Antarctic krill: Protein of the last frontier. Oceanus, 22(1), 13-20. McWhinnie, M. A., and Denys, C. 1978. Biological studies of antarctic krill, austral summer, 1977-1978. Antarctic Journal of the U. S., 13(4), 133-135. Ross, R. M., Daly, K. L., and English, T. S. 1982. Reproductive cycle and fecundity of Euphausia pacifica in Puget Sound, Washington. Limnology and Oceanography, 27(2), 304-314. Witek, Z., Koronkiewicz, A., and Soszka, G. J . 1980. Certain aspects of the early life history of krill Euphausia superba Dana (Crustacea). Polish Polar Research, 1(4), 97-115.
Pre-Recent Ross Sea sediments are distinguished by a diatom flora of mixed age whose frustules have undergone considerable chemical dissolution and severe mechanical breakage (Kellogg and Kellogg 1981; Kellogg, Truesdale, and Osterman 1979). We consider the discrepancy in ages of species present in these older sediments and their poor preservation to be hallmarks of reworking. Considering the regional distribution of these sediments, such reworking must have occurred on a very large scale. Reworked sediments can be produced by the action of bottom currents, former grounded ice sheets, and bottom-dwelling organisms. All three mechanisms might result in some degree of breakage and transport of frustules. Current action can be discounted as the dominant mechanism in most reworked sediment because it would result in obvious size sorting, such as occurs in the relatively rare sediments of the late GlacialRecent-aged Ross Sea Transition Zone (Kellogg, Osterman, and Stuiver 1979; Kellogg and Truesdale 1979) but not at other levels in Ross Sea cores (Anderson et al. 1980; Kellogg, Truesdale, and Osterman 1979). 167
In this article, we report the preliminary results of our efforts to distinguish the action of former grounded ice sheets from aspects of bioturbation by epifaunal organisms on the antarctic continental shelf. Our samples were the stomach contents of eight specimens of Ophionotus victoriae Bell (Echinodermata: Ophiuroidea) taken on three trawls off the Antarctic Peninsula at water depths of 50 to 80 meters (table 1) (Dearborn, Edwards, and Fratt 1981). This species is one of the most widely distributed and abundant brittle stars on the antarctic continental shelf, occurring at depths of from 5 to at least 750 meters (Dearborn 1977). First the specimens were dissected and their stomach contents prepared for diatom analysis by standard methods (Schrader 1974). Then nonoverlapping transects of each microslide were examined at a magnification of 1,000 until at least 100 diatom specimens had been identified or half the slides examined. Table 2 presents our diatom census data. With the possible exception of one questionable specimen of the Pliocene species Thalassiosira torokina Brady, all of the 52 species identified currently live in antarctic waters (Fenner, Schrader, and Wienigk 1976; Heiden and Kolbe 1928; Krebs 1977). Individual samples display a high degree of variability in species composition. Only two of the species—N it zschia cylindrus (Grunow) Hasle (dominant in most samples) and Navicula gelida var. parvula Heiden & Kolbe—occur in all eight samples. Other numerically important species include Bidduiphia weissflogii Janisch, Chaetoceros dichaeta Ehrenberg, Eucampia antarctica Castracane, Nitzschia curta (van Heurck) Hasle, N. heimii Manguin, and N. turgiduloides Hasle. Of these, only N. curta and E. antarctica are abundant in Recent Ross Sea sediments, although N. cylindrus often occurs there in low abundances (Truesdale and Kellogg 1979). Most of the remaining species had not been encountered previously in Ross Sea sediments. Because some of the differences between diatom assemblages in modern Ross Sea sediments and in the stomach contents of ophiuroids from the Antarctic Peninsula may be due to regional differences, a sampling program was carried out during 1981-82 to gather additional Ophionotus material together with the top layer of sediment on which they were living. Analyses of these samples will provide the first quantitative data on the relationship between diatom assemblages in antarctic sediments and the feeding habits of ophiuroids, an ecologically important group of macrobenthic invertebrates. Much of the difference observed in our preliminary study may be ascribed to differences in preservation within sediments. A high proportion of the diatoms from brittle star stomachs were complete, including fine surface markings, suggesting that diatom frustules undergo only a small amount of chemical dissolution and mechanical breakage as they are digested by Ophionotus victoriae. Moreover, since all these diatoms are of Recent age, 0. victoriae apparently disturb only the upper-
most layer of sediment and may not mix older and younger sediments significantly. Severe dissolution and breakage and the mixture of diatom assemblages of various ages in antarctic sediments probably are not caused by feeding and digestive processes in these ecologically dominant organisms. Regional reworking by grounded ice seems the most likely explanation for these features. This does not, however, preclude the possibility of dissolution and breakage of diatom frustules by other groups of benthic invertebrates. K. Austin prepared the diatom slides. This research was supported by National Science Foundation grants DPP 80-20000 (to T. B. Kellogg and D. E. Kellogg) and DPP 79-21537 (to J. H. Dearborn).
References Anderson, J. B., Kurtz, D. D., Domack, E. W., and Baishaw, K. M. 1980. Glacial and glacial marine sediments of the antarctic continental shelf. Journal of Geology, 88, 399-414. Dearborn, J . H. 1977. Foods and feeding characteristics of antarctic asteroids and ophiuroids. In G. A. Llano (Ed.), Adaptations within antarctic ecosystems. Washington, D.C.: Smithsonian Institution. Dearborn, J. H., Edwards, K. C., and Fratt, D. B. 1981. Feeding biology of sea stars and brittle stars along the Antarctic Peninsula. Antarctic Journal of the U.S., 16(5), 136-137. Fenner, J. , Schrader, H. J., and Wienigk, H. 1976. Diatom phytoplankton studies in the southern Pacific Ocean: Composition and correlation to the Antarctic Convergence and paleoecological significance. Initial Reports of the Deep Sea Drilling Project, 35, 757-813. Heiden, H., and Kolbe, R. W. 1928. Die marinen Diatomeen der Deutschen Sudpolar-Expedition, 1901-1903. Deutsche SOdpolar-Expedition, 1901-1903,8, 450-715. Kellogg, T. B., and Kellogg, D. E. 1981. Pleistocene sediments beneath the Ross Ice Shelf. Nature, 293, 130-133. Kellogg, T. B., Osterman, L. E., and Stuiver, M. 1979. Late Quaternary sedimentology and benthic foraminiferal paleoecology of the Ross Sea, Antarctica. Journal of Foraminiferal Research, 9, 322-335. Kellogg, T. B., and Truesdale, R. S. 1979. Late Quaternary paleoecology and paleoclimatology of the Ross Sea: The diatom record. Marine Micropaleontology, 4, 137-158. Kellogg, T. B., Truesdale, R. S., and Osterman, L. E. 1979. Late Quaternary extent of the west antarctic ice sheet: New evidence from Ross Sea cores. Geology, 7, 249-253. Krebs, W. N. 1977. Ecology and preservation of neritic marine diatoms, Arthur Harbor, Antarctica. Unpublished doctoral dissertation, University of California-Davis. Schrader, H. J . 1974. Proposal for a standardized method of cleaning diatom-bearing deep-sea and land-exposed marine sediment. Nova Hedwigia, Beiheft, 45, 403-409. Truesdale, R. S., and Kellogg, T. B. 1979. Ross Sea diatoms: Modern assemblage distributions and their relationship to ecologic, oceanographic, and sedimentary conditions. Marine Micropaleontology, 4, 13-31.
Table 1. Station details Station number
6
11 16
168
Date 2/16/81 2/17/81 2/22/81
General location Argentine Islands Argentine Islands Deception Island
Latitude (5)
Depth (meters)
Longitude (W)
64O1524 65014'30" 65°14'06" 64015'10" 62050"1 6" 60O3415
50-55 50-60 50-80
ANTARCTIC JOURNAL
Table 2. Number of specimens of various species found in the stomachs of eight specimens of
Taxon
Biddulphia anthropomorpha van Heurck (1909) Bidduiphia weissf/oggii Janisch (1862) Bidduiphia Gray (1821) sp. Chaetoceros atlanticus Cleve (1873) Chaetoceros castracanei Karsten (1905) Chaetoceros dichaeta Ehrenberg (1844) Chaetoceros sp. cf. adelianum Manguin (1957) Chaetoceros Ehrenberg (1844) spp. Charcotia actinochilus (Ehrenberg) Hustedt (1958) Cocconeis curiosa Hustedt (1958) Cocconeis imperatrix A. Schmidt (1894) Cocconeis schuettii van Heurck (1909) Corethron criophi/um Castracane (1886) Corethron Castracane (1886) sp. Coscinodiscus lentiginosus Janisch in A. Schmidt (1978) Coscinodiscus stellaris var. symbolophorus (Grunow) Jorgensen (1905) Cyc/otella compta (Ehrenberg) Kutzing (1849) Cyc/otella glomerata Bachmann (1911) Cyclotella stelligera Cleve & Grunow in van Heurck (1881) Dip/oneis Ehrenberg (1845) sp. Entomoneis paludosa (W. Smith) Reimer (1975) Eucampia antarctica (= E. ba/austium) Castracane (1886) Hantzschia amphioxys (Ehrenberg) Grunow (1877) Hemidiscus karstenll Jouse (1962) Licmophora decora Heiden & Kolbe (1928) Licmophora Agardh (1827) sp. Melosira distans (Ehrenberg) Kützing (1844) Melosira italica var. subarctica Muller (1906) Navicula directa (W Smith) Ralfs in Pritchard (1861) Navicula ge/ida var. parvula Heiden & Kolbe (1928) Navicula Bory (1822) spp. Nitzschia c/osterium (Ehrenberg) W. Smith (1853) Nitzschia curta (van Heurck) Hasle (1972) Nitzschia cy/indrus (Grunow) Hasle (1972) Nitzschia heimii (Manguin) Hasle (1965) Nitzschia kerguelensis (O'Meara) Hasle (1972) Nitzschia obliquecostata (van Heurck) Hasle (1972) Nitzschia separanda (Hustedt) Hasle (1972) Nitzschia sublineata (Hustedt) Hasle (1972) Nitzschia turgiduloides Hasle (1965) Nitzschia Hassal (1845) sp. Pleurosigma W. Smith (1853) sp. Schimperiella antarctica Karsten (1905) Synedra kergue/ensis Heiden & Kolbe (1928) Tabel/aria quadriseptata Knudson (1952) Thalassionema nitzschioides Grunow in van Heurck (1881) Tha/assiosira antarctica Comber (1896) Tha/assiosira delicatula Hustedt (1958) Tha/assiosira gracills (Karsten) Hustedt (1958) Thalas.siosira torokina Brady (1977) Thalassiosira Cleve (1873) spp. Thalassiothrix longissima Cleve & Grunow (1880) Total Number of transects examined
Ophionotus victorlae Bell
Station 6 a Station 11 Station 16 specimens specimens specimens 4b 175b lb 4b 18b 2b 4b 7b 0 8 0 0 0 0 3 0 0 0 0
0
0 4 0 0 0 9
0 0 0 0 2
0 10? 0 15?
0 4 0 0 0
0 0 0 0 0 0
0 2 0 0
2 0 0 4 5
0 2 0 0 0 15
0 0 0 0 0 3?
0
11? 0 0 0
0 0
0 0 0
0
0
0 0 2 1? 3 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 3
0
0 0 0 0 1? 0
0 0 0 1?
0
0 0 0
0 0 0 0 0 0
0 0 0 0 0
2 0 0 0 0 2
0 1? 11 0
0 0 0 2 0 0
0 0 0 14 0 0
4 0 0 4 0 0
0 0 0 2 0 0
0 0 0 3 0 0
0 0 0 0 2 4
0 0 0 0 0 5
0 0 0 0 0
0 0 0 0 0 8
0 0 0 0 0
0 0 0 0 2 11
7 0 0 0 2 2?
0
0 5 3 65 40 0
0
2 3 14 30 2 0
0 0 9 88 21 0
2
0 2 12 167 11 0
0 0 0 6 0 0
4 0
0
0 0 0
2 79 15 0
25? 0 0 0 0 0
10? 0 0 0 0 0
0 0 0 2 0 0
0 0
0 0 0 3 0 0
0 0 0 0 0
5 0 0
0 0 0 2
14 2
0 0 0 0 0
0 0 0
0
5 9 0 0
0 0 2 0 5 0
0 0 0 0 3 0
0 0 0 3 0
0 0 0 0 0 0
0 20 0 0 0 5
0 0 0 191
0 0 0 0 273
0 0 3 0 37
1? 0 0 69
10
5
10
10
190
77
0 0 0 0 179
10
10
9
10
0 0 3
0
0 4
0 0 37 0 0
0 0 4 2 141
0 0 11
3 131 13 0
0 0 0 0
4
0 0
a See table 1 for location of stations.
1982 REVIEW
169
superba
Investigators
Stage
Present McWhinnie & Denys Witek et al. study (1978) (1980) (USARP 82)
3-4 N.D.a 5-6 Egg to nauplius I Egg to nauplius II 7-8 N.D. 8-10 Egg to metanauplius 10-18 N.D. 15-18 Egg to calyptopis I N.D. 30 21-25 Egg to calyptopis II N.D. 45. 50, 60 b 32-37 "N.D. = no data. b Field estimates based on first, middle, and last time of spawning to first, middle, and last appearance of calyptopis II in the plankton.
Figure 2. Naupiii hatching from eggs released by Euphausla superba at Palmer Station during USARP 82. (Photo by L. B. Quetln)
port of our research efforts. This research was supported by National Science Foundation grant DPP 80-20739.
References March went on to hatch (figure 2). Usually, either all the eggs hatched or none hatched. We found developmental times for the naupliar stages comparable to those that McWhinnie and Denys (1978) found. Laboratory estimates of developmental times for the calyptopis stages, however, appear to be shorter than field estimates (Witek, Koronkiewicz, and Soszka 1980) (table 2). Newly hatched larvae must reach the surface in 21-25 days, if surface food sources are vital to their development at the first feeding stage (calyptopis 1). We thank Captain P. Lenie, the crew of the RJv Hero, and the support personnel at Palmer Station for their outstanding sup-
Diatoms from brittle star stomach contents: Implications for sediment reworking DAVIDA E. KELLOGG and THOMAS B. KELLOGG
Department of Geological Sciences
and Institute for Quaternary Studies University of Maine at Orono Orono, Maine 04469 JOHN H. DEARBORN, KELLY C. EDWARDS, and DAVID B. FRATT
Department of Zoology University of Maine at Orono Orono, Maine 04469
1982 REVIEW
El-Sayed, S., and McWhinnie, M. A. 1979. Antarctic krill: Protein of the last frontier. Oceanus, 22(1), 13-20. McWhinnie, M. A., and Denys, C. 1978. Biological studies of antarctic krill, austral summer, 1977-1978. Antarctic Journal of the U. S., 13(4), 133-135. Ross, R. M., Daly, K. L., and English, T. S. 1982. Reproductive cycle and fecundity of Euphausia pacifica in Puget Sound, Washington. Limnology and Oceanography, 27(2), 304-314. Witek, Z., Koronkiewicz, A., and Soszka, G. J . 1980. Certain aspects of the early life history of krill Euphausia superba Dana (Crustacea). Polish Polar Research, 1(4), 97-115.
Pre-Recent Ross Sea sediments are distinguished by a diatom flora of mixed age whose frustules have undergone considerable chemical dissolution and severe mechanical breakage (Kellogg and Kellogg 1981; Kellogg, Truesdale, and Osterman 1979). We consider the discrepancy in ages of species present in these older sediments and their poor preservation to be hallmarks of reworking. Considering the regional distribution of these sediments, such reworking must have occurred on a very large scale. Reworked sediments can be produced by the action of bottom currents, former grounded ice sheets, and bottom-dwelling organisms. All three mechanisms might result in some degree of breakage and transport of frustules. Current action can be discounted as the dominant mechanism in most reworked sediment because it would result in obvious size sorting, such as occurs in the relatively rare sediments of the late GlacialRecent-aged Ross Sea Transition Zone (Kellogg, Osterman, and Stuiver 1979; Kellogg and Truesdale 1979) but not at other levels in Ross Sea cores (Anderson et al. 1980; Kellogg, Truesdale, and Osterman 1979). 167
In this article, we report the preliminary results of our efforts to distinguish the action of former grounded ice sheets from aspects of bioturbation by epifaunal organisms on the antarctic continental shelf. Our samples were the stomach contents of eight specimens of Ophionotus victoriae Bell (Echinodermata: Ophiuroidea) taken on three trawls off the Antarctic Peninsula at water depths of 50 to 80 meters (table 1) (Dearborn, Edwards, and Fratt 1981). This species is one of the most widely distributed and abundant brittle stars on the antarctic continental shelf, occurring at depths of from 5 to at least 750 meters (Dearborn 1977). First the specimens were dissected and their stomach contents prepared for diatom analysis by standard methods (Schrader 1974). Then nonoverlapping transects of each microslide were examined at a magnification of 1,000 until at least 100 diatom specimens had been identified or half the slides examined. Table 2 presents our diatom census data. With the possible exception of one questionable specimen of the Pliocene species Thalassiosira torokina Brady, all of the 52 species identified currently live in antarctic waters (Fenner, Schrader, and Wienigk 1976; Heiden and Kolbe 1928; Krebs 1977). Individual samples display a high degree of variability in species composition. Only two of the species—N it zschia cylindrus (Grunow) Hasle (dominant in most samples) and Navicula gelida var. parvula Heiden & Kolbe—occur in all eight samples. Other numerically important species include Bidduiphia weissflogii Janisch, Chaetoceros dichaeta Ehrenberg, Eucampia antarctica Castracane, Nitzschia curta (van Heurck) Hasle, N. heimii Manguin, and N. turgiduloides Hasle. Of these, only N. curta and E. antarctica are abundant in Recent Ross Sea sediments, although N. cylindrus often occurs there in low abundances (Truesdale and Kellogg 1979). Most of the remaining species had not been encountered previously in Ross Sea sediments. Because some of the differences between diatom assemblages in modern Ross Sea sediments and in the stomach contents of ophiuroids from the Antarctic Peninsula may be due to regional differences, a sampling program was carried out during 1981-82 to gather additional Ophionotus material together with the top layer of sediment on which they were living. Analyses of these samples will provide the first quantitative data on the relationship between diatom assemblages in antarctic sediments and the feeding habits of ophiuroids, an ecologically important group of macrobenthic invertebrates. Much of the difference observed in our preliminary study may be ascribed to differences in preservation within sediments. A high proportion of the diatoms from brittle star stomachs were complete, including fine surface markings, suggesting that diatom frustules undergo only a small amount of chemical dissolution and mechanical breakage as they are digested by Ophionotus victoriae. Moreover, since all these diatoms are of Recent age, 0. victoriae apparently disturb only the upper-
most layer of sediment and may not mix older and younger sediments significantly. Severe dissolution and breakage and the mixture of diatom assemblages of various ages in antarctic sediments probably are not caused by feeding and digestive processes in these ecologically dominant organisms. Regional reworking by grounded ice seems the most likely explanation for these features. This does not, however, preclude the possibility of dissolution and breakage of diatom frustules by other groups of benthic invertebrates. K. Austin prepared the diatom slides. This research was supported by National Science Foundation grants DPP 80-20000 (to T. B. Kellogg and D. E. Kellogg) and DPP 79-21537 (to J. H. Dearborn).
References Anderson, J. B., Kurtz, D. D., Domack, E. W., and Baishaw, K. M. 1980. Glacial and glacial marine sediments of the antarctic continental shelf. Journal of Geology, 88, 399-414. Dearborn, J . H. 1977. Foods and feeding characteristics of antarctic asteroids and ophiuroids. In G. A. Llano (Ed.), Adaptations within antarctic ecosystems. Washington, D.C.: Smithsonian Institution. Dearborn, J. H., Edwards, K. C., and Fratt, D. B. 1981. Feeding biology of sea stars and brittle stars along the Antarctic Peninsula. Antarctic Journal of the U.S., 16(5), 136-137. Fenner, J. , Schrader, H. J., and Wienigk, H. 1976. Diatom phytoplankton studies in the southern Pacific Ocean: Composition and correlation to the Antarctic Convergence and paleoecological significance. Initial Reports of the Deep Sea Drilling Project, 35, 757-813. Heiden, H., and Kolbe, R. W. 1928. Die marinen Diatomeen der Deutschen Sudpolar-Expedition, 1901-1903. Deutsche SOdpolar-Expedition, 1901-1903,8, 450-715. Kellogg, T. B., and Kellogg, D. E. 1981. Pleistocene sediments beneath the Ross Ice Shelf. Nature, 293, 130-133. Kellogg, T. B., Osterman, L. E., and Stuiver, M. 1979. Late Quaternary sedimentology and benthic foraminiferal paleoecology of the Ross Sea, Antarctica. Journal of Foraminiferal Research, 9, 322-335. Kellogg, T. B., and Truesdale, R. S. 1979. Late Quaternary paleoecology and paleoclimatology of the Ross Sea: The diatom record. Marine Micropaleontology, 4, 137-158. Kellogg, T. B., Truesdale, R. S., and Osterman, L. E. 1979. Late Quaternary extent of the west antarctic ice sheet: New evidence from Ross Sea cores. Geology, 7, 249-253. Krebs, W. N. 1977. Ecology and preservation of neritic marine diatoms, Arthur Harbor, Antarctica. Unpublished doctoral dissertation, University of California-Davis. Schrader, H. J . 1974. Proposal for a standardized method of cleaning diatom-bearing deep-sea and land-exposed marine sediment. Nova Hedwigia, Beiheft, 45, 403-409. Truesdale, R. S., and Kellogg, T. B. 1979. Ross Sea diatoms: Modern assemblage distributions and their relationship to ecologic, oceanographic, and sedimentary conditions. Marine Micropaleontology, 4, 13-31.
Table 1. Station details Station number
6
11 16
168
Date 2/16/81 2/17/81 2/22/81
General location Argentine Islands Argentine Islands Deception Island
Latitude (5)
Depth (meters)
Longitude (W)
64O1524 65014'30" 65°14'06" 64015'10" 62050"1 6" 60O3415
50-55 50-60 50-80
ANTARCTIC JOURNAL
Table 2. Number of specimens of various species found in the stomachs of eight specimens of
Taxon
Biddulphia anthropomorpha van Heurck (1909) Bidduiphia weissf/oggii Janisch (1862) Bidduiphia Gray (1821) sp. Chaetoceros atlanticus Cleve (1873) Chaetoceros castracanei Karsten (1905) Chaetoceros dichaeta Ehrenberg (1844) Chaetoceros sp. cf. adelianum Manguin (1957) Chaetoceros Ehrenberg (1844) spp. Charcotia actinochilus (Ehrenberg) Hustedt (1958) Cocconeis curiosa Hustedt (1958) Cocconeis imperatrix A. Schmidt (1894) Cocconeis schuettii van Heurck (1909) Corethron criophi/um Castracane (1886) Corethron Castracane (1886) sp. Coscinodiscus lentiginosus Janisch in A. Schmidt (1978) Coscinodiscus stellaris var. symbolophorus (Grunow) Jorgensen (1905) Cyc/otella compta (Ehrenberg) Kutzing (1849) Cyc/otella glomerata Bachmann (1911) Cyclotella stelligera Cleve & Grunow in van Heurck (1881) Dip/oneis Ehrenberg (1845) sp. Entomoneis paludosa (W. Smith) Reimer (1975) Eucampia antarctica (= E. ba/austium) Castracane (1886) Hantzschia amphioxys (Ehrenberg) Grunow (1877) Hemidiscus karstenll Jouse (1962) Licmophora decora Heiden & Kolbe (1928) Licmophora Agardh (1827) sp. Melosira distans (Ehrenberg) Kützing (1844) Melosira italica var. subarctica Muller (1906) Navicula directa (W Smith) Ralfs in Pritchard (1861) Navicula ge/ida var. parvula Heiden & Kolbe (1928) Navicula Bory (1822) spp. Nitzschia c/osterium (Ehrenberg) W. Smith (1853) Nitzschia curta (van Heurck) Hasle (1972) Nitzschia cy/indrus (Grunow) Hasle (1972) Nitzschia heimii (Manguin) Hasle (1965) Nitzschia kerguelensis (O'Meara) Hasle (1972) Nitzschia obliquecostata (van Heurck) Hasle (1972) Nitzschia separanda (Hustedt) Hasle (1972) Nitzschia sublineata (Hustedt) Hasle (1972) Nitzschia turgiduloides Hasle (1965) Nitzschia Hassal (1845) sp. Pleurosigma W. Smith (1853) sp. Schimperiella antarctica Karsten (1905) Synedra kergue/ensis Heiden & Kolbe (1928) Tabel/aria quadriseptata Knudson (1952) Thalassionema nitzschioides Grunow in van Heurck (1881) Tha/assiosira antarctica Comber (1896) Tha/assiosira delicatula Hustedt (1958) Tha/assiosira gracills (Karsten) Hustedt (1958) Thalas.siosira torokina Brady (1977) Thalassiosira Cleve (1873) spp. Thalassiothrix longissima Cleve & Grunow (1880) Total Number of transects examined
Ophionotus victorlae Bell
Station 6 a Station 11 Station 16 specimens specimens specimens 4b 175b lb 4b 18b 2b 4b 7b 0 8 0 0 0 0 3 0 0 0 0
0
0 4 0 0 0 9
0 0 0 0 2
0 10? 0 15?
0 4 0 0 0
0 0 0 0 0 0
0 2 0 0
2 0 0 4 5
0 2 0 0 0 15
0 0 0 0 0 3?
0
11? 0 0 0
0 0
0 0 0
0
0
0 0 2 1? 3 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 3
0
0 0 0 0 1? 0
0 0 0 1?
0
0 0 0
0 0 0 0 0 0
0 0 0 0 0
2 0 0 0 0 2
0 1? 11 0
0 0 0 2 0 0
0 0 0 14 0 0
4 0 0 4 0 0
0 0 0 2 0 0
0 0 0 3 0 0
0 0 0 0 2 4
0 0 0 0 0 5
0 0 0 0 0
0 0 0 0 0 8
0 0 0 0 0
0 0 0 0 2 11
7 0 0 0 2 2?
0
0 5 3 65 40 0
0
2 3 14 30 2 0
0 0 9 88 21 0
2
0 2 12 167 11 0
0 0 0 6 0 0
4 0
0
0 0 0
2 79 15 0
25? 0 0 0 0 0
10? 0 0 0 0 0
0 0 0 2 0 0
0 0
0 0 0 3 0 0
0 0 0 0 0
5 0 0
0 0 0 2
14 2
0 0 0 0 0
0 0 0
0
5 9 0 0
0 0 2 0 5 0
0 0 0 0 3 0
0 0 0 3 0
0 0 0 0 0 0
0 20 0 0 0 5
0 0 0 191
0 0 0 0 273
0 0 3 0 37
1? 0 0 69
10
5
10
10
190
77
0 0 0 0 179
10
10
9
10
0 0 3
0
0 4
0 0 37 0 0
0 0 4 2 141
0 0 11
3 131 13 0
0 0 0 0
4
0 0
a See table 1 for location of stations.
1982 REVIEW
169
