BULLETIN OF MARINE SCffiNCE, 27(2): 241-255, 1977 LARVAL DEVELOPMENT OF SA BELLA RIA FLORIDENSIS FROM FLORIDA AND PHRAGMATOPOMA CALIFORNICA FROM SOUTHERN CALIFORNIA (POLYCHAETA : SABELLARIIDAE), WITH A KEY TO THE SABELLARIID LARVAE OF FLORIDA AND A REVIEW OF DEVELOPMENT IN THE FAMIL Y Kevin J. Eckelbarger ABSTRACT A laboratory study was conducted on the larval development, metamorphosis, and settlement behavior of Sabella ria floridensis from Florida, with additional observations on the development of Pllragmatopoma californica from California. Metamorphosis of S. floridensis larvae occurred 18 to 27 days from fertilization at 2l-23°C with many larvae metamorphosing in the absence of sand grains or other substrate. Metamorphosis was followed by a crawling or exploratory period ranging from several hours to several days before larvae constructed tubes and began a sedentary existence. The significance of this unusual behavior is discussed and compared to that of other sabellariids. A summary of systematically-useful larval characters for the identification of sabellariid larvae, a key to the sabellariid larvae of Florida and a comparison of larval development times within the family are presented. Information on the larval development of planktologist to make specific identifications eight species of sabellariids has appeared of sabellariid larvae from plankton samples. previously. These include three European This paper presents a comparison of larval species: Sabel/aria alveolata (Linne) (Wil- development times in sabellariids, a summary son, 1929, 1968a, 1970a; Cazaux, 1964); of systematically useful larval characters and Sabellaria spinulosa Leuckart (Wilson, 1929, a key to the sabeJlariid larvae of Florida. 1970b) and Lygdamis muratus (Allen) (Wilson, 1929; Bhaud, 1969, 1975a); two 'MATERIALS AND METHODS species from the east coast of North America: Sabellaria vulgaris Verrill (Novikoff, 1957; For the studies of larval development of Curtis, 1973; Eckelbarger, 1975) and Sabellaria floridensis, specimens were ob- Phragmatopoma lapidosa Kinberg (Mauro, tained in August 1974 from the Gulf Speci- 1975; Eckelbarger, 1976); a single species men Company Inc. The worms were col- from California: Phragmatopoma californica lected in the Apalachee Bay area, Wakulla (Fewkes) (Hartman, 1944; Dales, 1952); County, Florida. Spawning, handling and and a single species from the Indian Ocean: maintenance of eggs and larvae were carried Lygdamis indicus Kinberg (Bhaud, 1975b). out according to the procedures described by The present paper deals with an additional Eckelbarger (1975). The larvae were main- sabellariid from Florida, Sabel/aria floridensis tained at room temperature (21-23°C) in Hartman, as well as additional observations circulating sea water of the same salinity on Phragmatopoma californica from Cali- (25%0) in which the adults were collected. fornia. Drawings of paleae and spines were made Previous studies of larval development in by preparing whole-mounts of the larvae on sabellariids have demonstrated great similar- microscope slides and photographing them ities in larval morphology between the species with Kodachrome II color slide film through studied, thus making it difficult for the zoo- a Zeiss WL Research compound microscope 241 242 BULLETIN OF MARINE SCIENCE, VOL. 27, NO.2, 1977 equipped with phase and Nomarski differ- furnished by Dr. Marian H. Pettibone), come ential interference contrast optics. The from Texas (Port Aransas), Louisiana, Kodachrome slides were then projected on Florida (Panama City, Alligator Harbor, drawing paper with the aid of a Super Tampa Bay, Sarasota Bay, Broad River Chromega enlarger, and traced at the desired Delta in Everglades National Park, Seahorse scale, Drawings of entire larvae and juveniles Key), east coast of Florida (Marineland- were made free hand from living and pre- types of S. floridensis stephensoni Hartman, served specimens with the aid of compound 1949), Georgia (Sapelo Sound), South and dissecting microscopes, Carolina (Winyah Bay), and North Carolina Tubes of Phragmatopoma californica con- (Beaufort, Cape Hatteras). I have also col- taining several hundred sexually mature lected occasional specimens in shallow water specimens were purchased from Pacific Bio- on stones and shells offshore from Fort Pierce Marine Supply, Venice, California in July on the east coast of Florida, and on the spiny 1974. Adults were maintained in the labo- pen-shell, Atrina sp., scallop shells, and other ratory in aerated, fresh-filtered sea water pelecypods, which were washed ashore at (34%0) in a Percival E-30b environmental Sanibel Island, Lee County, and St. Peters- chamber at 17-18°C and fed every other burg Beach, Pinellas County on the west day with Dunaliella salina, Isochrysis gaibana, coast of Florida. and Chiorella autotrophica, The specimens Gamete-containing abdominal segments of were allowed to adjust to their new environ- mature males appear creamy-white, while ment for several days before spawnings were those of mature females are dark pink to lav- attempted. ender. Freshly spawned eggs range from Spawning and maintenance of eggs and 75-90 Jlm in diameter. Mature sperm possess larvae were carried out using the same pro- an elongate acrosome, thus modified from the cedures described above for Sabellaria flori- "primitive" polychaete type as defined by densis. Separate cultures of larvae were Franzen (1956). The head, including the maintained at two different temperatures: acrosome, is 6.4 Jlm in length while the tail 17-18°C and 21-23°C (room temperature). is about 32 J1.ffiin length. The early development parallels that of RESULTS other known sabellariids. The major differ- ences consist of a slightly slower rate of de- Larval Development of velopment in the early larval stages, the color Sabellaria floridensis of the larval chromatophores and the mor- Sabellaria fioridensis Hartman, 1944 phology of the opercular spines and paleac. Sabellaria fioridensis is a common inter- Ten to 12 h after fertilization, the trocho- tidal and shallow-shelf sabellariid polychaete, phares possess prototrochs, small apical tufts originally described from the west coast of and are swimming weakly. By 21 h, the Florida (Lemon Bay, Sarasota County) by apical tufts are larger, the posterior cilium has Hartman (1944). Additional published appeared and the larvae are swimming more records of this species include Playa de vigorously. The appearance of the first pair Tecolutla, Mexico (Rioja, 1946) and Alli- of provisional setae, four eyespots and ten- gator Harbor, Franklin County, Florida tacle buds all occur somewhat later than those (Hartman, 1951) in the Gulf of Mexico, of the two other sabellariids from Florida, and in North Carolina (Hartman, 1951; Sabellaria vulgaris and Phragmatopoma Day, 1973). Additional specimens of S. lapidosa, using the same culturing technique floridensis, on deposit in the United (see Table 1). States National Museum of the Smith- Older larvae (8-10 days) possess scattered sonian Institution, Washington, and checked yellow-green chromatophores which are by Dr. David Kirtley (information kindly gradually concentrated over the episphere. A ECKELBARGER: SABELLARIID LARVAL DEVELOPMENT 243 8 m o " 't: .. 3 c A Figure 1. Larva of Sabel/aria floridensis A-C: A. dorsal view of late larval stage just prior to metamor- phosis (about 17 days old); B. primary palea from opercular peduncle; C, larval nuchal spines from different individuals. Abbreviations: c. opercular cirrus; dh, dorsal hump; e. eyespot; t. tentacle. distinct row of yellow-green chromatophores days), a single, narrow, greenish-brown pig- was observed in many larvae along the dorsal ment band forms over the dorsal and lateral and lateral posterior margins of the episphere, portions of the trunk segments. When the roughly outlining the prototroch. A similar tentacle buds appear (13-15 days), three of band of reddish-black chromatophores was these bands are present. found in Sabellaria vulgaris larvae (Eckel- Figure 1 shows a late larval stage about 17 barger, 1975). As development proceeds, days from fertilization. It agrees with previ- the chromatophores on the episphere develop ously described sabellariids, having four red brownish flecks which tend to mask the green eyespots, a pair of long tentacles, a well- color observed earlier. Bright green chro- developed prototroch and telotroch, two matophores appear on the pygidium and re- bundles of long, barbed, provisional setae, a main throughout larval development. Before dorsal hump posterior to the eye-spots, three the formation of tentacle buds (about 10-12 parathoracic segments with dorsal para- 244 BULLET]N OF MARINE SCIENCE, VOL. 27. NO.2, ]977 Figure 2. Larva of Sabel/aria floridensis in early stage of metamorphosis A-B: A, dorsal view; B, ventral view. Abbreviations: ab, first abdominal segment; bo, building organ; c, opercular cirrus; m, mouth; ne, neurotroch; no, nototroch; ns, nuchal spine; opp, opercular peduncle; pp. primary paleae; pt, first parathoracic segment. podial lobes each bearing four capillary spines were observed in the larvae of S. setae and three abdominal segments with floridensis. Following metamorphosis, the dorsal uncinigerous lobes. nuchal spines will elongate and move closer The tentacles are about one-half the body to the midline near the eyespots. The black length and have yellow-green chroma to- dorsal pigment bands remain but may be phores scattered over their entire dorsal broken along the median line in some larvae. surfaces.