From Hawai'i1

Three New Species of Saccocirrus (Polychaeta: Saccocirridae) from Hawai'i 1 J. H. Bailey-B1'ock,2,3 J. Dreyer,2 and R. E. Brock 4 Abstract: Three new species of saccocirrids from interstitial sand habitats off O'ahu, Hawai'i, are described. Two are from subtidal depths, 9-33 m, and the third is from the intertidal to 3.5 m deep on a fringing reef and at Hanauma Bay, the Marine Life Conservation District and public park. The two deeper-water species, Saccocirrus oahuensis, n. sp. and S. waianaensis, n. sp., have 76-119 and 157-210 segments, respectively; they also have bilateral gonads but lack a pha ryngeal pad. The third, S. alanhongi, n. sp., has 35-47 segments, unilateral gonads, and a muscular pharyngeal pad. These species are distinguished from 18 known Saccocirms spp. by their unique chaetation, number of segments, pres ence or absence of ventral cilia, and pygidial adhesive structures. Saccocirms oahuensis consumes foraminiferans, and S. alanhongi contained diatoms, unicel lular algae, and ostracods. These species add to the interstitial fauna of O'ahu and cooccur with polychaetes Nerilla antennata (Nerillidae) and protodrilids (Protodrilidae), and Kinorhyncha. Saccocirms alanhongi withstands almost daily disturbance by 600-1200 bathers per day entering the sandy swimming holes in the reef at Hanauma Bay. SACCOCIRRIDS WERE FIRST recorded from Fauna ofHawai'i (Bailey-Brock 1987). Sacco Hawai'i in 1979, when they were found in cirridae were classified as "Archiannelida," sand on a shallow fringing reef near Pearl which included Protodrilidae, Nerillidae, Di Harbor on the south shore of O'ahu, Hawai'i nophilidae, and Polygordiidae (Jouin 1971, (Bailey-Brock 1979). This unnamed species Westheide 1985). This old grouping of five from Fort Kamehameha reef was added to families has since been discarded (Westheide the polychaete fauna as Saccocirrus sp. in a re 1985, 1990) and all are families of Polychaeta. vision of C. H. Edmondson's Reefand Shore Westheide's papers emphasized the intersti tial habitat as a unifying characteristic of eight families, including the five just listed and Protodriloidae, Diurodrilidae, and Parergo 1 This study was funded by the Department of Envi drilidae. Representatives oftwo families, Meso ronmental Services, City and County of Honolulu, Ha nerilla fagei and Nerilla antennata (Nerillidae) wai'i, under contract no. 54997 to the Water Resources and Protodrilus sp. (Protodrilidae), are known Research Center, and the Hanauma Bay Carrying Ca from Hawai'i (Bailey-Brock 1987,1999). Re pacity study to R. E. Brock. This is contributed paper CP-2003-02 of the Water Resources Research Center, cently another protodrilid species, Parentero University of Hawai'i at Manoa, Honolulu. Manuscript drilus sp., was collected off Ni'ihau, Hawai'i, accepted 18 December 2002. and awaits further study. In this paper we add 2 Water Resources Research Center, University of three species of Saccocirms collected from Hawai'i at Manoa, 2540 Dole Street, Holmes Hall 283, sand habitats in a shallow bay and on fringing Honolulu, Hawai'i 96822. 3 Department of Zoology, University of Hawai'i at reefs to depths of 35 m off O'ahu, Hawai'i. Manoa, 2538 McCarthy Mall, Honolulu, Hawai'i 96822. 4 University of Hawai'i Sea Grant Extension Pro gram, 2525 Correa, Honolulu, Hawai'i 96822. MATERIALS AND METHODS Collections were made by hand with a corer Pacific Science (2003), vol. 57, no. 4:463-478 7.6 cm in diameter by 5 cm deep from 0.5- to © 2003 by University of Hawai'i Press 3.5-m depths in Hanauma Bay and from the All rights reserved seaward side of the intertidal reef flat at Fort 463 464 PACIFIC SCIENCE· October 2003 Kamehameha, bordering the entrance to Saccocirrus alanhongi Bailey-Brock, Dreyer & Pearl Harbor. Scuba divers collected sedi Brock, n. sp. ment cores of medium-grain calcareous sand Figures 1-4 off Wai'anae, and at Mamala Bay stations off the south shore of O'ahu. Those from greater TYPE MATERIAL: Holotype: USNM 1012494, depths (50 m or more) were taken with a van Hanauma Bay, O'ahu, Hawai'i, at depths of Veen grab deployed from a research vessel. 0.5-3.5 m, 27 July 1999. Paratypes: USNM All were preserved in 10% buffered formalin 1012495-1012497, same data as holotype. and Rose Bengal for 24 hr or more, elutriated DESCRIPTION: Specimens measure 2.7 over 0.50- and 0.25-mm mesh sieves, and 3.4 mm in length and 0.25-0.30 mm in width. stored in 70% ethanol. Preserved specimens Number of segments ranges between 35 and were mounted in glycerol on slides and ex 47 (Figure lA). One pair of long, wrinkled amined with phase contrast and dark and cephalic tentacles measuring 0.40-0.72 mm bright field microscopy. Magnifications for extends about one-third of the body length line drawings made with a compound micro (Figure IB-D). The first 1 or 2 segments and scope with lOx eyepieces are from 40 to posterior segments 3-11 are achaetous. One 1000 x with oil. Specimens of the three spe pair of red eyes is present on the rounded cies were examined with scanning electron prostomium (Figure IB). Eyes present as microscopy (SEM) using a field emission ciliary patches (Figure 3A,B). Nuchal organs microscope (Hitachi S-800) operating at are a dorsal groove between prostomium and 15 KV after ethanol dehydration and coating peristomium (Figures IB,C; 2A; 3A,B). A with gold-palladium. Specimens of S. alan muscular pharyngeal pad (Figure IB) and hongi were dried with a critical point drier ventral mouth (Figures ID, 2A-C) are pres (Autosamdri-81O). Specimens of the other ent. Cilia are on the ventral surface of the species were air dried on parafilm in a desic prostomium (Figure 2A,B), around the cator because the drier required extensive re mouth (Figure 2A-D), and in the midline to pair or replacement. Micrographs were saved the third chaetiger (Figure 2A,B). Paddlelike as TIFF images and prepared as plates with cilia around the mouth may be actual features Adobe Photoshop. or artifacts of specimen preservation (Figure 2D). Parapodia are uniramous with 3 types of chaetae per fascicle (Figures IG, 3C, 4A). RESULTS The first type is longest, having a terminal Three new species of Saccocirridae Czer fork with unequal branches and a short, ser niavsky, 1881, found in sand collected from rated median projection that gives a tri the south, east, and west shores of O'ahu are dentate appearance at 100x oil, 1 or 2 per described here. Numerous specimens of fascicle (Figures 1G,H; 3C,D). The median Saccocirrus alanhongi were collected in sand region is composed of 6 short, digitiform from Hanauma Bay (southeastern O'ahu) on projections (Figure 3D); one in the middle is 27 July 1999, and they were abundant (483 longer and broader than the others. The sec specimens) in coarse sands at Fort Kameha ond type is a medium-length forked chaeta meha reef flat (southern O'ahu) collected with equal-length prongs; margins in the fork in 1977 (Bailey-Brock 1979). Specimens of appear smooth at 100x oil (Figure IG), but Saccocirrus oahuensis were collected in sedi 4-6 serrations along the distal part of the ments adjacent to four O'ahu sewage outfalls: inner margins are visible with SEM (Figure Wai'anae on the west, Sand Island and Bar 4A), 3 per fascicle. The third type is a short, bers Point on the south, and Mokapu on the simple chaeta with a terminal notch, 2-3 per east. Four specimens of Saccocirrus waianaensis fascicle (Figures IG; 4A,C). Clusters of 3 were found off the Wai'anae sewage outfall, peglike structures and a few single apertures three off the sandy beach fronting Waimanalo (Figure 4B) were evident across the ventrum on the east coast of O'ahu, and one off Hilo of anterior segments. Pegs are possibly solid Bay, Hawai'i. ified adhesive material and the holes remain New Species of Saccocirrus from Hawai'i . Bailey-Bl'ock et al. 465 H FIGURE 1. SaccochnLS alal1bol1gi. A, Entire worm, dorsal to lateral view; B, anterior, dorsal view, prostomium, peri stomium, cephalic tentacles, apertures ofnuchal organs, pharyngeal pad; C, anterior, lateral view, groove defining nuchal organs; C), nuchal organ cilia; D, anterior, ventral view; E, F, papillate pygidium; G, three types of chaetae; H, long chaetae (G, H lOOx oil). Scales: A, 0.2 mm; B, C, Cl, D, 0.1 mm; E, 0.2 mm; F, 0.05 mm; G, 0.01 mm; H, 0.02 mm. when the material is extruded. Gonads are men), lobes 0.06-0.15 mm in length, each assumed to be unilateral due to the presence lobe with 4-6 ridges with adhesive papillae of the pharyngeal pad, and one specimen was on the inner surface, without anal cirri (Fig collected with eggs on one side of the gut. ures 1E,F; 4D). Pygidium bifurcated (trifurcated in 1 speci- REMARKS: Long chaetae resemble those 466 PACIFIC SCIENCE· October 2003 FIGURE 2. Scanning electron micrographs of Saccoci17'US alanhongi. A, Anterior region, view of cephalic tentacles, nuchal organs, and mouth; B, mouth surrounded by cilia, ventral groove cilia, and folded oral membrane; C, peristomial cilia and oral membrane; D, paddlelike peristomial cilia (see text for discussion). Scales: A, 60 11m; B, 30 11m; C, 10.0 11m; D, 3.8 11m. of Saccocirrus tridentiger Brown, 1981, but the were present). Medium chaetae number two Australian species has a curved short branch to four in S. tridentiger and two to three in S. and three chaetae per fascicle whereas S.

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