Literature records of tintinnid distributions (272 references, 1899 to 1992) were plotted with a computer. Distributions at the genus level revealed several distinct biogeographic patterns: cosmopolitan, neritic, warm-water, boreal, and austral. Some of the factors that may account for these patterns are examined. At the species level, certain disjunct distributions are examined, including the bipolar distribution of Acanthostornella norvegica and the interoceanic distributions of tropical tintinnids. Endemicism of species within certain genera, such as Codonellopsis, was also found.

ABSTRACT. Copepod nauplii may be an important intermediary between the 'microbial' and 'classical' pelagic marine food webs. In studies of planktonic food webs, along a trophic gradient from eutroph~c harbour through coastal to oligotrophic oceanic waters off Jamaica, West Indies, we investigated bacterivory by nauplii of 11 representative copepod taxa (n = 176 total nauplii) using fluorescently labelled bacteria (FLB) of 0.7 pmholume at concentrations of 1.5 to 2.5 X 10"ells ml-l Seven taxa consistently ingested FLB: Acartia liljeborgii, Paracalanus spp., Temora stylifera, T turbinata, Oncaea spp., Undinula vulgaris, Oithona spp.; 4 taxa consistently did not: Centropages velificatus, CJausocalanus spp., Euchaeta marina, and Corycaeus spp. These data, and the observations that naupliar moulting and growth rates were uncoupled from chlorophyll a concentrations in any size fraction over the range 0.09 to 4.7 mg m-3, suggest that nauphi are not food limited even in oceanic waters. Calculations indicate that daily food requirements of oceanic nauplii can be met from a diet of bacteria and picoplankton, but not from a diet of nano-and net-phytoplankton. Naupliar production in oceanic waters is at least 50 to 60% of copepodite production; it appears therefore that the ecological importance of copepod nauplii in oceanic waters has been greatly underestimated.

As part of a larger study of hydrography, water chemistry and plankton in Buzzards Bay, Massachusetts. USA, we quantified levels of nutrients (ammonium, nitrate, nitrite, orthophosphate, silicate), chlorophyll a and phaeopigments from 1 October 1987 to 11 September 1990 (n = 1080 for each parameter). Although there were considerable monthly, seasonal and interannual fluctuations of some variables, certain trends were apparent. Ammonium comprised up to 99.79 % (mean = 75.79%) of total dissol~~ed inorganic nitrogen (DIN = NH4+ + NO3-+ NOz-). This was due to nutrient loading at one station from a sewage outfall, and to resuspension of benthic nutrients due to shallow depth and frequent mixing throughout the entire bay. Nitrate levels were maximal in winter, whereas those of orthophosphate were h g h e r during the warmer months. Both variables exhibited interannual variation. Silicate exhibited sustained bay-wide summer increases in all 3 years, followed by precipitous declines in autumn. Inverse relationships between silicate and diatoms during 1987 to 1988 suggest that silicate fluctuations were biologically related, in that the summer increase was a rebound from heavy utilization during the spring diatom bloom, and the autumn sillcate decline was due to utilization by a fall diatom bloom. Chlorophyll a levels were comparatively high (>5.0 mg I-') and relatively uniform throughout the bay except for higher concentrations near the sewage outfall, or within an enclosed harbor where a hurricane dike appears to increase residence times of phytoplankton blooms by reducing circulation. Buzzards Bay is a habitat favorable to high phytoplankton production because shallow depth and frequent mixing result in a water column that is holomictic and euphotic throughout most of the year, and the sediments act as a nutrient pump injecting ammonium and other rernineralized nutrients into the water column.

Using scanning electron microscopy, we examined the undigested contents of fecal pellets from hand-collected Oikopleura vanhoeffeni Lohmann. Our goals were to compare the size of food in fecal pellets to the pore size of the incurrent filters, and to compare the size and type of food in fecal pellets to the size and type of food available in the environment. We collected 0. vanhoeffeni in coastal waters of Newfoundland in May 1983, during the spring diatom bloom, a n d in January 1984, when diatoms were rare. Because the pore size of the incurrent filters was large (X = 169 X 88 pm), 0. vanhoeffeni was able to ingest the large, armored cells and diatom chains present during the spring bloom. The largest cells in fecal pellets were smaller than the mean pore width of the incurrent filters. The largest single cell in fecal pellets was the silicoflagellate Distephanus speculum (48 pm in diameter). Many tabular chains of pennate diatoms in fecal pellets were >40 pm long. Spinous Chaetoceros socialis were ingested. In January, the fecal pellet contents were dominated by coccoliths along wlth common dinoflagellates and diatoms. Each fecal pellet was surrounded by a peritrophic membrane.

Tintinnids were collected from Buzzards Bay. Massachusetts. USA, from October 1987 to September 1988. Tintinnids were collected by screening 3 1 of seawater with a 20 pm mesh. Eight stations throughout the bay were sampled at monthly or twice-monthly intervals. A total of 30 species of tlntinnids were recorded, half of which were members of the genus Tintinnopsis. Tintinnid abundances ranged from 0 to 3.3 X 103 cells I-'. Tintinnlds were least abundant at the Cape Cod Canal and in northern Buzzards Bay, and most abundant at the New Bedford sewage outfall. Unlike dinoflagellates, tintinnids did not show higher abundances in New Bedford Harbor than in the main part of the bay. The effect of screening tintinnid samples with a 20 pm mesh screen was examined by comparisons of abundance of tintinnids in screened and unscreened whole-water samples concentrated by gravitational sedimentation. Tintinnid abundance estimates were significantly higher in the screened samples.