Essential Fish Habitat Descriptions for Western Pacific Archipelagic and Remote Island Areas Fishery Ecosystem Plan Management Unit Species (Crustacean, Bottomfish, Precious Coral, Coral Reef Ecosystem) Western Pacific Regional Fishery Management Council 1164 Bishop Street, Suite 1400 Honolulu, Hawaii 96813 December 1, 2005 A-1 Essential Fish Habitat Descriptions for Western Pacific Archipelagic and Remote Island Areas Fishery Ecosystem Plan Management Unit Species (Crustacean, Bottomfish, Precious Coral and Coral Reef Ecosystem Species) TABLE OF CONTENTS 4.1.1 Surgeonfish (Acanthuridae) ..................................................................................... 137 4.1.2 Triggerfish (Balistidae) ............................................................................................ 138 4.1.3 Big Eye Scad (Selar crumenophthalmus) and Mackerel Scad (Decapterus macarellus) ....................................................................................................................... 140 4.1.4 Gray Reef Shark (Carcharhinus amblyrhynchos; Carcharhinidae) ......................... 140 4.1.5 Soldierfish/Squirrelfish (Holocentridae) .................................................................. 141 4.1.6 Flag-tails (Kuhliidae) ............................................................................................... 142 4.1.7 Rudderfishes (Kyphosidae) ...................................................................................... 142 4.1.8 Wrasses (Labridae) .................................................................................................. 143 4.1.9 Napoleon Wrasse (Cheilinus undulatus) ................................................................. 145 4.1.11 Mullets (Mugilidae) ............................................................................................... 147 4.1.12 Moray Eels (Muraenidae) ...................................................................................... 148 4.1.13 Octopuses (Octopodidae) ....................................................................................... 149 4.1.14 Threadfins (Polynemidae) ...................................................................................... 150 4.1.15 Bigeyes (Priacanthidae) ......................................................................................... 151 4.1.16 Parrotfishes (Scaridae) ........................................................................................... 152 4.1.17 Bumphead Parrotfish (Bolbometopon muricatum) ................................................ 153 4.1.18 Rabbitfish (Siganidae) ........................................................................................... 153 4.1.19 Barracudas (Sphyraenidae) .................................................................................... 155 4.1.20 Turban Shells/Green Snail (Turbinidae) ................................................................ 155 4.1.21 Aquarium Taxa/Species Habitat ............................................................................ 156 4.1.21.1 Surgeonfishes (Acanthuridae) ......................................................................... 157 4.1.21.2 Moorish Idol (Zanclus cornutus; Zancildae) .................................................. 158 4.1.21.3 Angelfishes (Pomacanthidae) ......................................................................... 158 4.1.21.4 Dragon Moray (Enchelycore pardalis; Muraenidae) ...................................... 158 4.1.21.5 Hawkfishes (Cirrhitidae) ................................................................................. 159 4.1.21.6 Butterflyfishes (Chaetodontidae) .................................................................... 160 4.1.21.7 Damselfishes (Pomacentridae)........................................................................ 160 4.1.21.8 Turkeyfishes (Scorpaenidae) .......................................................................... 161 4.1.21.9 Feather-duster Worms (Sabellidae) ................................................................ 162 Bibliography ..................................................................................................................... 162 4.2.1 EFH for Management Unit Species B Fish ............................................................... 168 4.2.1.1 Acanthuridae (surgeonfishes) ........................................................................... 168 4.2.1.2 Carcharhinidae, Sphyrnidae, Triaenodon obesus (sharks) ............................... 177 4.2.1.3 Dasyatididae, Myliobatidae, Mobulidae (rays) ................................................. 182 4.2.1.4 Chlopsidae, Congridae, Moringuidae, Ophichthidae (eels) .............................. 184 4.2.1.5 Engraulidae (anchovies) .................................................................................... 188 4.2.1.6 Clupeidae (herrings).......................................................................................... 191 4.2.1.7 Antennariidae (frogfishes) ................................................................................ 193 4.2.1.8 Anomalopidae (flashlightfish) .......................................................................... 196 A-2 4.2.1.9 Holocentridae (soldierfishes/squirrelfishes) ..................................................... 198 4.2.1.10 Aulostomidae (trumpetfishes) ......................................................................... 201 4.2.1.11 Fistularidae (cornetfish) .................................................................................. 203 4.2.1.12 Syngnathidae (pipefishes/seahorses) .............................................................. 205 4.2.1.13 Caracanthidae (coral crouchers) ..................................................................... 207 4.2.1.14 Tetrarogidae (waspfish) .................................................................................. 209 4.2.1.15 Scorpaenidae (scorpionfishes) ........................................................................ 211 4.2.1.16 Serranidae (groupers) ...................................................................................... 214 4.2.1.17 Grammistidae (soapfish) ................................................................................. 219 4.2.1.18 Plesiopidae (prettyfins) ................................................................................... 221 4.2.1.19 Pseudochromidae (dottybacks) ....................................................................... 223 4.2.1.20 Acanthoclinidae (spiny basslets) ..................................................................... 225 4.2.1.21 Cirrhitidae (hawkfish) ..................................................................................... 227 4.2.1.22 Apogonidae (cardinalfishes) ........................................................................... 229 4.2.1.23 Priacanthidae (bigeyes) ................................................................................... 232 4.2.1.24 Malacanthidae (tilefishes) ............................................................................... 234 4.2.1.25 Echineididae (remoras) ................................................................................... 236 4.2.1.26 Carangidae (jacks, papio, ulua) ...................................................................... 238 4.2.1.27 Decapterus/Selar (scads, opelu, akule) ........................................................... 242 4.2.1.28 Caesionidae (fusiliers) .................................................................................... 244 4.2.1.29 Haemulidae (sweetlips) ................................................................................... 246 4.2.1.30 Lethrinidae (emperors) .................................................................................... 249 4.2.1.31 Lutjanidae (snappers) ...................................................................................... 251 4.2.1.32 Mullidae (goatfishes) ...................................................................................... 254 4.2.1.33 Kyphosidae (rudderfishes) .............................................................................. 257 4.2.1.34 Monodactylidae (monos) ................................................................................ 259 4.2.1.35 Ephippidae (batfishes, spadefishes) ................................................................ 261 4.2.1.36 Chaetodontidae (butterflyfishes) ..................................................................... 263 4.2.1.37 Pomacanthidae (angelfishes) .......................................................................... 266 4.2.1.38 Genicanthus personatus (masked angelfish) .................................................. 269 4.2.1.39 Pomacentridae (damselfishes) ........................................................................ 272 4.2.1.40 Labridae (wrasses) .......................................................................................... 275 4.2.1.41 Cheilinus undulatus (humphead wrasse) ........................................................ 283 4.2.1.42 Scaridae (parrotfishes) .................................................................................... 286 4.2.1.43 Bolbometopon muricatum (bumphead parrotfish) .......................................... 290 4.2.1.44 Polynemidae (threadfins) ................................................................................ 292 4.2.1.45 Sphyraenidae (barracudas) .............................................................................. 295 4.2.1.46 Pinguipedidae (sandperches) .......................................................................... 298 4.2.1.47 Blenniidae (blennies) ...................................................................................... 300 4.2.1.48 Gobiidae (gobies) ............................................................................................ 303 4.2.1.49 Zebrasoma flavescens (yellow tang) ............................................................... 307 4.2.1.50 Zanclidae (Moorish idol) ................................................................................ 309 4.2.1.51 Siganidae (rabbitfishes) .................................................................................. 311 4.2.1.52 Gymnosarda unicolor (dogtooth tuna)............................................................ 314 4.2.1.53 Bothidae/Soleidae/Pleuronectidae (flounder and soles) ................................. 317 A-3 4.2.1.54 Balistidae/Monocanthidae (triggerfishes/filefishes) ....................................... 320 4.2.1.55 Ostraciidae (trunkfish) .................................................................................... 323 4.2.1.56 Tetradontidae/Diodontidae (puffers/porcupinefishes) .................................... 326 4.2.2 EFH for Management Unit Species B Invertebrates ................................................. 329 4.2.2.1 Cephalopods ...................................................................................................... 329 4.2.2.2 Tunicates ........................................................................................................... 332 4.2.2.3 Bryozoans ......................................................................................................... 337 4.2.2.4 Crustaceans ....................................................................................................... 342 4.2.2.5 Bibliography .................................................................................................... 361 4.2.3 EFH for Management Unit Species B Sessile Benthos ............................................. 367 4.2.3.1 Algae ................................................................................................................. 369 4.2.3.2 Porifera (sponges) ............................................................................................. 425 4.2.3.3 Millepora sp. (Linnaeus, 1758) (stinging or fire coral) .................................... 437 4.2.3.4 Stylasteridae (Gray, 1847) (Stylasterines; lace corals) ..................................... 439 4.2.3.5 Solanderidae (Gray) (hydroid fans) .................................................................. 441 4.2.3.6 Scleractinia (stony corals) ................................................................................. 443 4.2.3.7 Fungiidae (Dana, 1846) (mushroom corals) ..................................................... 455 4.2.3.8 Ahermatypic Corals (Azooxanthellate) ............................................................ 484 4.2.3.9 Actiniaria (anemones) ....................................................................................... 487 4.2.3.11 Subclass Alcyonaria (=Octocorallia); Order Alcyonacea; Suborder Alcyoniina (soft corals) ................................................................................................................... 499 4.2.3.12 Subclass Alcyonaria (=Octocorallia); Order Alcyonacea; Suborder Scleraxonia; Holoaxonia (gorgonian corals, sea fans and sea whips) ............................................... 504 4.2.3.13 Heliopora coerulea (DeBlainville, 1830) (Alcyonaria, Coenothecalia) (blue coral) ............................................................................................................................. 507 4.2.3.14 Tubipora Musica (Linnaeus, 1758) (organ-pipe coral or star polyps) ............ 510 1. CRUSTACEAN SPECIES This section is divided up between spiny lobster, slipper lobster, and Kona crab in Hawaii and spiny lobster in the other islands of the Western Pacific Region. This is because the only significant fisheries for crustaceans, primarily spiny lobsters and slipper lobsters, are found in Hawaii. Moreover, these fisheries use traps, which are not used extensively for crustaceans outside of Hawaii, and which are used in Hawaii to target other crustaceans such as Kona crab and white crabs. Moreover, while other spiny lobsters are widespread in the Pacific Islands and the US Western Pacific Region, the target of the lobster fishery in Hawaii, Panulirus marginatus, is found only in Hawaii, Johnson Island and Wake Island. Further, a major component of the Hawaii lobster fishery is the slipper lobster Scyllarides squammosus. Slipper lobsters, which are not targeted to any extent by other fisheries in the Western Pacific, may be taken opportunistically by divers. Throughout the other Pacific Islands, including American Samoa, Mariana Islands and the Pacific Remote Islands, the most common spiny lobster found on rocky and coral reefs, A-4 apart from Hawaii, is Panulirus penicillatus, while other species such as P. versicolor, P.ornatus and P.longipes have also been observed, but are much less common. 1.1 Hawaii 1.1.1 Habitat Adult spiny lobsters are typically found on rocky substrate in well protected areas, in crevices and under rocks (Pitcher 1993, FAO 1991). Spiny lobsters found in Hawaii include both Panulirus marginatus and P. penicillatus. However, most fishing for lobsters in Hawaii is targeted at P. marginatus and the slipper lobster Scyllarides squammosus, and these species are the focus of this review. An extensive review of the EFH for P. penicillatus is included in the FEPs for Mariana Islands, American Samoa and the PRIAs. Unlike many other species of Panulirus, the juveniles and adults of P. marginatus are not found in separate habitat apart from one another (MacDonald and Stimson 1980, Pitcher 1993, Parrish and Polovina 1994). Juvenile P. marginatus recruit directly to adult habitat; they do not utilize separate shallow water nursery habitat apart from the adults as do many Palinurid lobsters (MacDonald and Stimson 1980, Parrish and Polovina 1994). Juvenile and adult P. marginatus do utilize shelter differently from one another (MacDonald and Stimson 1980). Similarly, juvenile and adult P. pencillatus also share the same habitat (Pitcher 1993). In the NWHI, P. marginatus is found seaward of the reefs and within the lagoons and atolls of the islands (WPRFMC 1983). Uchida (1986) reports that P. penicillatus rarely occurs in the commercial catches of the NWHI lobster fishery. In the NWHI, P. pencillatus is found inhabiting shallow waters (<18 m) (Uchida and Tagami 1984). In the NWHI, the relative proportion of slipper lobsters to spiny lobsters varies between banks; several banks produce relatively higher catch rates of slipper lobster than total spiny lobster (Uchida 1986; *Clarke et al. 1987, WPRFMC 1986). The slipper lobster is taken in deeper waters than the spiny lobster (Clarke et al., 1987, WPRFMC 1986). Uchida (1986) reports that the highest catch rates for slipper lobster in the NWHI occur between the depths of 20B55 m. Pitcher (1993) observes that, in the southwestern Pacific, spiny lobsters are typically found in association with coral reefs. Coral reefs provide shelter as well as a diverse and abundant supply of food items, he notes. Pitcher also states that in this region, P. pencillatus inhabits the rocky shelters in the windward surf zones of oceanic reefs, an observation also noted by Kanciruk (1980). Other species of Panulirus show more general patterns of habitat utilization, Pitcher continues. At night, P. penicillatus moves on to reef flat to forage, Pitcher continues. Spiny lobsters are nocturnal predators (FAO 1991). 1.1.2 Morphology A-5 Spiny lobsters are non-clawed, decapod crustaceans with slender walking legs of roughly equal size (Uchida 1986, FAO 1991). Spiny lobster have a large spiny carapace with two horns and antennae projecting forward of their eyes and a large abdomen terminating in a flexible tailfan (FAO 1991). Uchida (1986) provides a detailed description of the morphology of the slipper lobsterv Scyllarides squammosus and S. haanii. He notes that the two species are very similar in appearance and are easily confused (Uchida 1986). The appearance of the slipper lobster is notably different than that of the spiny lobster. 1.1.3 Reproduction Spiny lobsters (Panulirus sp.) are dioecious (Uchida 1986). Generally, the different species of the genus Panulirus have the same reproductive behavior and life cycle (Pitcher 1993). The male spiny lobster deposits a spermatophore or sperm packet on the female=s abdomen (WPRFMC 1983, Uchida 1986). In Panulirus sp., the fertilization of the eggs occurs externally (Uchida 1986a). The female lobster scratches and breaks the mass, releasing the spermatozoa (WPRFMC 1983). Simultaneously, ova are released for the female=s oviduct and are then fertilized and attach to the setae of the female=s pleopod (WPRFMC 1983, Pitcher 1993). At this point the female lobster is ovigerous, or Aberried@ (WPRFMC 1983). The fertilized eggs hatch into phyllosoma larvae after 30B40 days (MacDonald 1986, Uchida 1986). Spiny lobsters are very fecund (WPRFMC 1983). The release of the phyllosoma larvae appears to be timed to coincide with the full moon and dawn in some species (Pitcher 1993). In Scyllarides sp. fertilization is internal (Uchida 1986b). 1.1.4 Larval Stage Very little is known about the planktonic phase of the phyllosoma larvae of Panulirus marginatus (Uchida et al. 1980). After hatching, the Aleaf-like@ larvae (or phyllosoma) enter a planktonic phase (WPRFMC 1983). The duration of this planktonic phase varies depending on the species and geographic region (WPRFMC 1983). The planktonic larval stage may last from 6 months to 1 year from the time of the hatching of the eggs (WPRFMC 1983, MacDonald 1986). There are 11 dissimilar morphological stages of development that the phyllosoma larvae pass through before they transform into the postlarval puelurus phase (Johnson 1986, MacDonald 1986). The pelagic phyllosoma stage of development is followed by the puerulus stage. The puelurus stage lasts 6 months or less (WPRFMC 1983). Spiny lobster pueruli are free- swimming and actively return to shallow, nearshore waters in preparation for settlement (WPRFMC 1983, MacDonald 1986). Johnston (1973) reports that the phyllosoma phase of some species of the genera Scyllarides is somewhat shorter. MacDonald and Stimson (1980) found pelagic, puerulus larvae settlement to occur at approximately 1 cm in length. MacDonald (1986) found puerulus settlement occurred primarily at the new moon and A-6 first quarter lunar phase in Hawaii. The settlement of puerulus is higher in the central portion of the Hawaiian Island chain than what, and it is higher in the NWHI than around the MHI (MacDonald 1986). There is a lack of published data pertaining to the preferred depth distribution of phyllosoma larvae in Hawaii. However, the depth distribution of phyllosoma larvae of other species of Panulirus common in the Indo-Pacific region has been documented. Phillips and Sastry (1980) reports that the newly hatched larvae of the western rock lobster (P. cygnus) is typically found within 60 m of the surface. Later stages of the phyllosoma larvae are found at depths between 80B120 m. P. cygnus undergoes a diurnal vertical migration, ascending to the surface at night, descending to lower depths during the day, the authors add. The authors also note that research has shown that early phyllosoma larvae display a photopositive reaction to dim light, In the Gulf of Mexico, the depth to which Panulirus larvae descend is restricted by the depth of the thermocline, Phillips and Sastry note. MacDonald (1986) state that after settlement the pueluri molt and transform into post- pueruli, a transitional phase between the pelagic phyllosama phase and the juvenile stage. Yoshimura and Yamakawa (1988) note that very little is known about the habitat requirements of Palinurid pueruli after settlement occurs. However, Pitcher (1993) states that the post-pueruli of Panulirus penicillatus has been observed inhabiting the same Ahigh-energy reef-front habitat@ as adults of the species. Studying the benthic ecology and habitat utilization of newly settled pueruli and juveniles of the Japanese spiny lobster (P. japonicus), Yoshimura and Yamakawa (1988) conclude that microhabitats, such as small holes in rocks and boulders and algae, provide important habitat for the newly settled pueruli and juvenile lobsters. The Japanese spiny lobster is found inhabiting shallow waters at depths of 1B15 m on rocky bottom (FAO 1991). The oceanographic and physiographic features that result in the retention of lobster larvae within the Hawaiian archipelago are not understood (WPRFMC 1983). Johnston (1968) suggests that fine-scale oceanographic features, such as eddies and currents, serve to retain phyllosoma larvae within the Hawaiian Island chain. In the NWHI, puerulus settlement appears to be linked to the north and southward shifts of the North Pacific Central Water (NPCW) type (MacDonald 1986). The relatively long pelagic larval phase for palinurids results in very wide dispersal of spiny lobster larvae; palinurid larvae are transported up to 2,000 miles by prevailing ocean currents (Johnston 1973, MacDonald 1986). 1.1.5 Life Histories and Habitat Descriptions for Crustacean Species 1.1.5.1 Habitat Description for Hawaiian Spiny Lobster (Panulirus marginatus and Scyllarides squammosus) A-7 Management Plan and Area: American Samoa, Guam, MHI, NWHI, Northern Mariana Islands, Johnston Atoll, Kingman Reef, Palmyra Atoll, Jarvis Island, Midway Island, Howland and Baker Islands and Wake Islands. The Hawaiian spiny lobster, within the Council=s jurisdiction are managed under the FMP for the Crustaceans of the Western Pacific Region General Description and Life History The Hawaiian spiny lobster (Panuliris marginatus) is endemic to the Hawaiian Islands and Johnston Atoll (Brock 1973, FAO 1991). The relative abundance of P. marginatus at Johnston Atoll is very low (Brock 1973). The spiny lobster is distributed throughout the entire NWHI, from Kure Atoll to Nihoa (Uchida 1986a). P. marginatus is the principal species landed in the NWHI spiny lobster fishery (WPRFMC.1983).The reported depth distribution of this species in the NWHI is 5B100 fm (WPRFMC 1983). While this species is found down to depths of 100 fm it usually inhabits shallower waters (FAO 1991). Uchida and Tagami (1984) report that P. marginatus is most abundant in waters of 90 m or less. Moffitt (1998, pers. comm.) states that spiny lobster are found in greatest abundance between the depths of 10B50 fm. At Maro Reef, in the NWHI, large adult spiny lobsters have been captured at depths as shallow as 10 feet (Moffitt 1998, pers comm.). Uchida and Tagami (1984) note that within the NWHI, there is a dramatic shift between depth and relative abundance. They report that in the vicinity of the northern most islands and banks relative abundance of spiny lobsters was highest at depths of 19B54 m and that at the lower end of the chain the highest abundance of spiny lobsters were observed between 55B73 m. North of Maro Reef the highest relative abundance of spiny lobsters is found at shallower depths, they continue. They suggest that this variability may be due to differences in the temperature regime in the NWHI. P. marginatus is typically found on rocky substrate in well-protected areas such as crevices and under rocks (FAO 1991). During the day, spiny lobsters are found in dens or crevices in the company of one or more other lobsters (WPRFMC 1983). MacDonald and Stimson (1980), studying the population biology of spiny lobsters at Kure Atoll in the NWHI, found that 57% of the dens examined were inhabited by solitary lobsters. The remaining 43% were occupied by more than one lobster, with adult and juvenile lobsters of both sexes often found sharing the same dens. However, the authors note, adult and juvenile spiny lobsters exhibit distinctly different den occupancy patterns, with juveniles (less than 6 cm in carapace length) typically in multiple occupancy dens with other lobsters. Adult and juvenile spiny lobsters are not segregated by geographic area or habitat type at Kure Atoll, MacDonald and Stimson observe. They found that juvenile spiny lobsters do not utilize separate nursery habitats apart from the adult lobsters. The larval spiny lobster puerulus recruits directly to the adult habitat (Parrish and Polovina 1994). This is in contrast to the juveniles of other species of spiny lobsters that tend to reside in A-8 shallow water and migrate to deeper, offshore waters as they mature (MacDonald and Stimson 1980). There are limited data available concerning growth rates, reproductive potentials and natural mortality rates at the various life history stages (WPRFMC 1983). The relationship between egg production, larval settlement, and stock recruitment are poorly understood (WPRFMC 1983). Egg and larval distribution The Hawaiian spiny lobster (P. marginatus) is dioecious (Uchida 1986a). The male spiny lobster deposits a spermatophore or sperm packet on the female=s abdomen (WPRFMC 1983, Uchida 1986a). In P. marginatus, fertilization of the eggs occurs externally (Uchida 1986a). The female lobster scratches and breaks the mass, releasing the spermatozoa (WPRFMC 1983). Simultaneously, ova are released for the female=s oviduct, where they are then fertilized and attach to the setae of the female=s pleopod (WPRFMC 1983). At this point the female lobster is ovigerous, or Aberried@ (WPRFMC 1983). The fertilized eggs hatch into phyllosoma larvae after 30B40 days (MacDonald 1986, Uchida 1986a). The spawning season for P. marginatus varies throughout the Hawaiian Island chain (Uchida 1986a). In the northwestern end of the NWHI spawning occurs primarily during the early summer months (Uchida et al. 1980, Uchida, 1986a). MacDonald and Stimson (1980) found ovigerous females at Kure Atoll between the months of May to September. Uchida et al (1980) found the peak abundance of ovigerous female lobsters at Nihoa, French Frigate Shoals between late summer and early winter. It is believed that reproduction is nearly continuous in the warmer waters south of Maro Reef in the NWHI (WPRFMC 1983). Around the island of Oahu spawning occurs year-round (Uchida 1986a). In the MHI, peak spawning activity occurs between the months of May and August with a minimal amount of activity from November to January (Uchida 1986a). Egg-bearing females are found year-round in the MHI (WPRFMC 1983). Spiny lobsters are very fecund (WPRFMC 1983). Honda (1980) found that fecundity increased with size. Most female spiny lobsters reach sexually maturity at 2 years of age (WPRFMC 1983). Estimating size at maturity for male and female spiny lobsters at Necker Island and Oahu, Prescott (19 *) concludes the Necker Island females reach sexual maturity at 60.7 mm, males at 59.2 mm, while Oahu females reach sexual maturity at 58.6 mm, males at 63.6 mm. At Necker Island the smallest mated lobster observed was 48.3 mm; it is not conclusive that the ovaries of females are mature at this size (Uchida and Tagami 1984). Growth rates for male spiny lobsters at Necker Island have been calculated as follows: 3.7 cm CL at 1 year, 5.7 cm at 2 years, 7.3 cm at 3 years, 8.5 cm at 4 years, 9.4 cm at 5 years and 10.1 cm in 6 years (Uchida 1986a). Due to insufficient data the growth of females has not been calculated (Uchida 1986a). Larvae A-9 After hatching, the larvae (or phyllosoma) enter a planktonic phase (WPRFMC 1983). The duration of this planktonic phase varies depending on the species and geographic region (WPRFMC 1983).Very little is known about the planktonic phase of the phyllosoma larvae of P. marginatus (Uchida et al.1980). The planktonic larval stage may last from 6 months to 1 year from the time of the hatching of the eggs (WPRFMC 1983, MacDonald 1986). There are 11 dissimilar stages of development that the phyllosoma larvae pass through before they transform into the postlarval puelurus phase (Johnson 1968, MacDonald 1986). The pelagic phyllosoma stage of development is followed by the puerulus stage. Spiny lobster pueruli are free-swimming and actively migrate into shallow, near-shore waters in preparation for settlement (WPRFMC 1983, MacDonald 1986). The puelurus stage lasts 6 months or less (WPRFMC 1983). MacDonald and Stimson (1980) found pelagic, puerulus larvae settlement to occur at approximately 1 cm in length. After settlement the pueluri molt and transform into postpueruli, a transitional phase between the pelagic phyllosama phase and the juvenile stage (MacDonald 1986). It is believed, that because of the endemic nature of P. marginatus in the Hawaiian archipelago, the resident population is the source of larval recruits (Uchida et al. 1983). Shaklee (1962) found no genetic variation within the various spiny lobster populations at the different islands and banks in the NWHI chain. These data suggest that a single stock of spiny lobster exists in the NWHI (WPRFMC 1983). Recruitment of puerulus lobster larvae occurred at Kure Atoll beginning in the spring and lasting to October; no recruitment occurred from October to March (MacDonald and Stimson 1980). The distribution of lobster larvae in the waters surrounding the banks and islands of the NWHI is patchy (Parrish and Polovina 1994). Settlement of palinurid larvae tends to be higher in the middle of the Hawaiian Island chain and higher in the NWHI than in the MHI (MacDonald, 1986). There is evidence that the recruitment of puelerus lobster larvae is tied to the lunar phase with maximum recruitment occurring during the new moon and first quarter phases (MacDonald and Stimson 1980). Juvenile distribution Parrish and Polovina (1994) found that banks with summits deeper than 30 m had consistently lower catches of spiny lobster; six of eight banks surveyed with summits at depths greater then 30 m did not provide commercial quantities of spiny lobster. They suggest a depth threshold may prevent the successful settlement and/or survival of pueruli of the spiny lobster in commercial quantities at these banks. Parrish and Polovina (1994) studied the production rates of three banks in the NWHI; two commercially productive banks, Maro Reef and Necker Island, and one commercially unproductive bank, Lisianski. In this study the percent coverage of the different substrate types were measured and classified into four habitat types. The intermediate relief habitat A-10