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Notes: Abstract To investigate the natural defenses of Antarctic marine organisms against exposure to ultraviolet (UV) radiation (280 to 320 nm), 57 species (1 fish, 48 invertebrates, and 8 algae) were collected during austral spring 1988 in the vicinity of Palmer Station (Anvers Island, Antarctic Peninsula) and were analyzed for the presence of mycosporine-like amino acids (MAAs), compounds that absorb UV radiation and may provide shielding from these biologically hazardous wavelengths. Nearly 90% of the 57 species examined contained MAAs, and eight specific MAA compounds were identified. Seven of these (palythine, porphyra-334, shinorine, mycosporineglycine, palythene, asterina-330, and palythinol) have been observed previously in marine organisms from temperate and tropical latitudes. A new MAA, mycosporineglycine: valine, was found in the Antarctic fish and in 38 of the invertebrate species examined. This study confirms widespread occurrence of MAAs in Antarctic marine organisms and suggests that these species have some degree of natural biochemical protection from UV exposure.

Notes: Abstract Reproduction and development of two psolid sea cucumbers in waters of the San Juan Archipelago, Washington, were studied from April 1981 through August 1984. Spawning inPsolus chitonoides Clark andPsolidium bullatum Ohshima in the laboratory and in the field waters of the San Juan Archipelago, Washington, occurred from February through may, with heaviest spawning in April and May. The egg ofPsolus chitonoides was bright red in color and 627µm in diameter;Psolidium bullatum released eggs that were golden yellow in color and 330µm in diameter. Maximum measured fecundities (spawned eggs) forPsolus chitonoides andPsolidium bullatum were 34 700 and 3 074, respectively. Developmental schedules were similar in both species. Early cleavages were equal, radial, and holoblastic; slightly subequal cleavage was common inPsolus chitonoides. The gastrula elongated to form a uniformly ciliated larva and the vestibule first appeared as a ventral crescent-shaped depression, after which the larva decreased in length and formed three posterior ridges that encircled the early doliolaria. Just prior to settlement, there was loss of cilia between the three ridges and on the posterior end of the early doliolaria, leaving three ciliary rings that are characteristic of the dendrochirote doliolaria larva. Vertical swimming ensued, and five primary tentacles protruded through the vestibule, with occasional attachment to the substratum using the primary tentacles. Upon settlement, two primary podia emerged and all external ciliation was lost except among tentacular papillae and on the end of tube feet. Timing of appearance and of loss of ciliary rings suggest that the rings function in vertical swimming and substratum selection behaviors. Metamorphosis involved the following simultaneous events: (1) resorption of the preoral lobe, (2) formation of large, dorsal, calcareous ossicles, (3) flattening of the trivium, and (4) proliferation of ventral tube feet on Ambulacral Radii B and E to form the sole. Reproduction in the family Psolidae is reviewed. The large proportion of brooders in this family appears to be related to small size, the possession of protective armor and sole, and geographic distribution (mainly in Antarctica). Lecithotrophic doliolaria larvae with three ciliary rings are produced by large northern psolids.

Notes: Abstract Known reproductive patterns in the polychaete family Sabellidae include: (1) broadcasting of gametes, (2) depositing of benthic egg masses, (3) brooding outside the lip of the tube, and (4) brooding within the tube. There is little information for sabellids in the third category; there-fore we have studied the reproductive biology of Sabella (=Demonax) media (Bush), one of the few species known to brood its early developmental stages outside the tube. A total of 32 adults of S. media with egg cocoons were collected from the surfaces of compound ascidians (Aplidium sp. and Didemnum sp.) and from holdfasts of a brown alga (Hedophyllum sessile) at Eagle Cove, San Juan Island, Washington, USA, from June 1981 through June 1982, between tidal levels of 0.0 and 0.6 m. The donutshaped cocoons, each containing over 1 000 eggs, are deposited just outside the tube aperture from April through September. Larval development takes place within the cocoon through the 3-setiger stage, at which time the larvae emerge (about 8 d after egg deposition). The newly hatched larvae are demersal and swim near the bottom of the culture dish for 1 d before settlement. Metamorphosis takes nearly a week, and initial formation of the tube is also gradual. The reproductive patterns within the family Sabellidae are discussed, and the adaptive significance of extratubular brooding considered.

Notes: Abstract Spawning behaviors observed from May 1981 through August 1983 in the laboratory and field are described and compared for twelve species of northeast Pacific holothuroids collected from waters of the San Juan Archipelago, Washington. For many species, elevation of the anterior end, stretching of the introvert, tentacle waving, and swaying are behaviors commonly associated with gamete release. Less common activities include waving of introvert podia, waves of body wall contractions, errant males, aggregations, and pseudocopulation. Positively buoyant eggs of four species [Psolus chitonoides Clark, Cucumaria miniata (Brandt), C. piperata (Stimpson), and C. fallax (Ludwig)] were packaged in pellets, ropes, or strands and released passively; a female Molpadia intermedia (Ludwig) discharged negatively buoyant eggs in a single explosive burst. Two externally brooding sea cucumbers [C. lubrica (Clark) and C. pseudocurata Deichmann] produced strands of dilution-resistant sperm that were carried by currents to nearby females. Three species commonly sympatric [P. chitonoides, C. miniata, and Eupentacta quinquesemita (Selenka)] in high-current rocky habitats have overlapping spring breeding seasons, but spawn at different hours of the day.