Juvenlle white mullet Mug11 curema a n d juvenile strlped mullet Mugd cephalus actlvely lngested marine snow In the laboratory Thls IS the flrst expenmental venflcatlon of the consumptlon of manne snow by a vertebrate The stomach contents of fish fed manne snow In the laboratory were compared to flsh collected from the Charleston Harbor estuary, South Carollna USA and the coastal Atlantlc Ocean Results suggest that juvenile mullet consume m a n n e snow In the natural environment In food cholce experiments in whlch mullet were offered a choice between manne snow and zooplankton (Artemia sp ), consumptlon of manne snow was Inversely related to zooplankton concentrations Mullet ass~mllated organlc matter and total a m n o a c~d s from m a n n e snow wlth efficlencies of 49 2 and 55 8 % respectively These efficiencies are comparable to those of flsh feedlng on benthic detntus The contnbution of manne snow to the growth of juvende mullet was tested in growth experiments by feeding mullet different combinations of m a n n e snow and zooplankton (Artemia s p ) Mullet d~d not exhlbit positive growth on a d~e t of marlne snow (speclhc growth rate = -1 34 % d ') M a n n e snow contributed to the diet of mullet by slowing welght loss (by 5 0 % ) especially when con~plemented wlth zooplankton (an additional 5 0 % )

ABSTRACT. The assoc~atlon of larval polychaetes with manne snow was investigated ( l ) w~t h SCUBA to sample marine snow In the f~e l d and (2) in laboratory experiments. The field sampling took place in the Atlantic Ocean off Charleston, South Carolina, USA 13 sample dates) and in the Pacific Ocean at 2 locations around the San Juan Islands, Washington, US:\ (7 sample dates). On all of the sample dates marine snow was present and abundant ( r m g e 1 to 63 agg. I-'). Larval polychaetes were signif~cantly concentrated on aggregates on 7 of the 10 sample dates. Larval polychaetes from 12 families \yere present in the plankton samples of which 10 families were found associated with aggregates. On average. 1 6 % (SD = 22%) of all larval polychaetes were on aggregates. Precompetent and competent larval polychaetes made up 84 and 16% respectively of the larval polychaetes in the plankton. O n average 20% of all precompetent polychaete larvae were on aggregates. In contrast, competent polychaete larvae were strongly associated with aggregates with 80":) of the competent larval polychaetes on aggregates. Laboratory experiments using 4 polychaete species and laboratory-made marine snow also found that larval polychaetes were concentrated on aggregates In d vel tical flume, observations were made on the behavior of larval polychaetes following contact with aggregates. Upon contacting m a n n e snow, larval polychaetes crawled into or over the surface of aggregates for several minutes before swimming away. Thesc field and laboratory observations suggest that a precompetent polychaete larva m~g h t spend about 5 h d.! vlsiting aggregates and that during a day ~t may vis~t about 90 aggregates. C0mpeten.t larval polychaetes may spend > l 9 h d.' on aggregates. Polychaete larvae visiting or residing on aggregates may be feedlng on the aggregate microbial community. Further, the vertical flux and, perhaps, benthic deposition of larvae residing in aggregates is d u e to the sinking of the marine snow. Clearly, marine snow is a n important component of the environment for many types of polychaete ldrvae and adaptations to life In aggregates nld): have played a role in the evolution of polychaete larval traits.