Development times from egg to adult Calanus marshallae (Copepoda, Crustacea) were 36 d at 15 'C, 62 d at 11 "C and 64 d at 10 'C. Stage-by-stage development was not isochronal but followed a sigmoidal pattern. Egg, NI and N2 together took 3.4 d at 10 "C (= 5.3 % of the total development time). N3 had the second longest duration of any stage (6.8 d at 10 "C; 10.7 % of total development). Stage duration decreased from N3 through N6, with N6 having the shortest duration of any stage (2.6 d), then development became progressively slower through each copepodite stage. C5 had the longest duration (20.9 d; 32.8 % of total development time). Body lengths of laboratory-raised stages NI to C3 were the same as of field-collected specimens; C4 and C5 were shorter than in wild copepods, but laboratory-raised females were significantly longer than wild females. This suggests that laboratory growth conditions were probably as good as, if not better than, conditions in the field. Weight was gained at a rate of 0.05 pg pg-I d-I from egg through N4; 0.18 d-' from N5 to C5; 0.02 d -' from C5 to adult female. It is argued that observed deviations from isochronal development in Calanus marshallae may reflect differential mortality rates among developmental stages such that stages that on average experience high mortalities will develop most rapidly.

Egg production by adult female Calanus marshallae Frost was studied in the laboratory by making a census of the number of eggs produced each day by individuals maintained on a diet of the diatom Thalassiosira weissflogii. When fed ad libitum individuals produced a clutch of 30 eggs every 30 h on average. Egg production rates were influenced by food concentration, ranqng from 0 d-' when females were kept in filtered seawater up to 24 eggs d-' at food concentrations 2 3500 cells m]-'.

We measured bacterioplankton abundance and productivity during 3 upwelling cycles at a nearshore station off central Chile (36"309S) in January 1986. Standing stock (43 to 113 X 1 0 '~ cells m-2 over the 25 m water column) and productivity were lowest during periods of active upwelling and highest during periods of calm or hght winds and water column strabfication. Bactenal productivity peaked 1 to 2 d after primary productivity and varied by about an order of magnitude (0.13 to 1.40 pgC 1-1 h-1) between newly upwelled and stratified waters. Surface primary productivity was much more variable (50-fold variation) and thus appeared to respond more strongly to the hydrographic events of the upwelling cycle. Net bacterial production was often a substantial fraction of primary production (up to about 50 %), especially in newly upwelled water The abundance of heterotrophic microflagellates also varied in response to the upwelling cycle, with maximum abundances occurring during periods of strahfication. The duration of stratified conditions between successive upwelling events may determine how much bacterial production is mineralized by grazers in the nearshore zone and how much is subsequently transported offshore.

We estimated in situ ingestion rates of females of the calanoid copepod Temora longicornis in Long Island Sound, New York, USA, at roughly weekly intervals, between February and August from 1985 to 1987 using the gut fluorescence technique. Variability in gut pigment content (GPC) and ~ngestion rates (IR) was examined in relation to changes in the concentration of total chlorophyll and of chlorophyll in the > 20 vm size fractions, and changes in body size. Correlations of GPC and IR with chlorophyll concentration were highest for the > 20 Km size fraction and lowest for total chlorophyll. Saturation of GPC and IR was apparent only when phytoplankton > 10 pm or > 20 pm was considered as available food. These results lend support to the notion that the degree to which herbivorous coastal copepods are food-limited may be strongly dependent on the structure of the phytoplankton assemblage Prosome length of female T long~corn~s decreased by almost a factor of 2, and dry weight by a factor of 4, from February to August Correlations between weight-specific GPC, welght-specific IR and chlorophyll concentration in all size fractions were poorer than in the cases of GPC and IR on a per mdlvidual basis However, a multivariate regression analysis indicated that most of the vanance in GPC and IR was explained by the different size fractions of chlorophyll, not body weight. Therefore, the use of weight-specific indices may not always be justified even when variation in body size is pronounced. We suggest that multivanate analysis or other statistical techniques b e employed, instead of weightspecific indices, when body size may be a confounding vanable.

Sand lance larvae consumed phytoplankton and various developmental stages of the copepods Ternora longicornis, Acartia hudsonica and Pseudocalanus sp. Their diet changed with ontogeny: small larvae consumed phytoplankton and larger larvae ate copepods of increasingly older developmental stages. Samples taken during daylight indicated that the larvae have a gut capacity of approximately 0.56 % of their body dry weight. Laboratory studles conducted with live larvae indicated non-selective feeding on copepod n a u p h , but in the field, Ivlev indlces indicated selection for T 1ong1corni.s nauplii and against A. hudsonjca n a u p h . Larger larvae selected for T longicornjs copepodites and against A. hudsonica copepodites and females, but as they approach metan~orphosis, they began to select for A. hudsonica females. The feeding behavior of small larvae is passive, but becomes more aggressive as the larvae mature. Biomass consumed Increased with Increased prey density and water temperature. Clearance rates for larvae at 7OC In the laboratory were 0.02, 0.05, 0.48 and 3.2 1 d -' for 4.5 to 5.0, 6 to 7.0, 10 to 11.0, and 21 mm ldrvae, respectively. Calculations of the predatory impact of sand lance larvae on copepod nauplii ind~calu that they are lnslgnificant consumers taking a maximum of 13.4 % of the copepod production per ddy.