Collections and Submarine Observations of Deep BenthicFishes and Decapod Crustacea in Hawaii1

THOMAS A. CLARKE2

ABSTRACT: Depths between 150 and 400 m off Oahu, Hawaii, were surveyedby submarine, gill nets, and traps. Depth of capture or observations and otherdata are given for 47 species of fishes and 20 species of decapod Crustacea. Ofthese species, 10 fishes and five crustaceans are either undescribed or new recordsfor Hawaii. Four other fishes collected and several others observed from the sub­marine are probably undescribed or unrecorded species. A large proportion ofboth the total number of species collected and of the new forms were taken bygill net. The gill nets are able to sample steep, rocky bottoms and obtain types oforganisms inaccessible to other types of gear, particularly bottom trawls.

THE DEEP WATER BENTHIC FAUNA of theHawaiian Islands is known mainly from resultsof deep bottom trawling by the Albatross nearthe turn of the century (Gilbert, 1905) andfrom a few subsequent trawling-dredging col­lections. Such collections have undoubtedlymissed some forms and, as Gosline (1965) hasnoted, data on depth distribution are inade­quate. Brock and Chamberlain (1968) andStrasburg, Jones, and Iverson (1969) havereported on submersible observations down toabout 200 m. These data have extended depthranges and provided interesting observationson many organisms, but, because of the depthlimits of the submersible, have included fewdeep-water species. The only other sources ofdeep-water specimens have been fishermen whohave collected occasional individuals by hand­line, and volcanic eruptions during which speci­mens have floated to the surface following lavaflows into deep water (Gosline, Moore, andYamaguchi, 1954).

This paper presents results of a survey duringwhich a submersible and several types of fishinggear were utilized. The efforts were concen-

1 Hawaii Institute of Marine Biology Contributionno. 368. This work was supported by State of HawaiiFisheries Funds to the University of Hawaii and bySea Grant GH-62 and GH-93. Manuscript received6 December 1971.

2 University of Hawaii: Department of Oceanog­raphy Honolulu, Hawii 96822, and Hawaii Instituteof Marine Biology, P. O. Box 1067, Kaneohe, Oahu,Hawaii.

trated on steep, rocky bottoms between 150 and400 m depths. The investigation was restrictedto fishes and decapod Crustacea. The resultsprovide records of several species new toHawaii, depth ranges of these and many others,information on the habits of some species, anda basis for comparing the effectiveness of dif­ferent survey methods.

METHODS

The submersible used was the Naia, operatedby Pacific Submersibles, Inc. Naia's maximumdepth is about 400 m. She carries a pilot andtwo observers (fore and aft). Four dives weremade (9, 12, 14, and 22 September 1968).All were during the daytime, between 0945and 1600. Only cursory observations were madeabove 150 m. The maximum depths attainedranged from 255 to 380 m. Time per divebelow 150 m averaged about 150 minutes. Allobservations were recorded on a tape recorder.Fish poison was released on most dives. Un­fortunately, the submarine's collecting arm didnot function properly and only two fish wererecovered from the bottom. (Three more werefound floating on the surface after a poisoningat 155 m).

Traps and gill nets were usually set inthe evening and retrieved the following morn­ing. Traps were of 2.5, 1.2, and 0.6 em wiremesh and were baited with fish and/or squid.Most were about 1.0 X 0.5 X 0.5 m3 in

310

Deep Benthic Fishes and Decapod Crustacea in Hawaii-CLARKE 311

dimensions, but one large trap about 2 X 2 X 3m3 was used on one cruise. Gill nets of 12.5,7.5, and 3.7 em stretch mesh multifilamentnylon were used. Each set included severalmesh sizes in a string about 200 m long withanchors and float lines at each end.

Standard length of the fishes, and carapacelength of Crustacea were in most cases mea­sured to the nearest mm; occasionally, withlarger specimens, less precise measurementswere made in the field. The identifications usedhere are mostly from Gosline and Brock (1965)and Rathbun (1906). Where these provedinadequate, specialists were consulted. Allnames used here which are either tentative oruncertain are discussed briefly in the appendix.Representatives of rare, unrecorded, and newspecies that are not currently in the hands oftaxonomists have been deposited in the BerniceP. Bishop Museum, Honolulu, Hawaii.

STUDY AREAS

The submarine dives were all made offBarbers Point at the southwest corner of theisland of Oahu. Most of the gillnet fishing wasdone near the sites of the sub's dives; depthcoverage and dates are shown in Table 1. Atotal of 22 traps was set between about 170and 365 m in this area on the same dates.Trapping effort was about evenly distributedthrough the depth zone.

The bottom near Barbers Point droppedsteeply from about 100-120 m to about 300 ffi.

TABLE 1

DATES AND DEPTHS OF GILLNET SETS MADE OFF

BARBERS POINT, OAHU, NEAR THE AREAWHERE SUBMARINE DIVES WERE MADE

The slope angle ranged from 60° to 90°. Inmany places the cliff face was smooth rock withlittle or no sediment covering. The only reliefwas small ledges or canyons in the face of thecliff. Below 300 m, the bottom was coarse sandwith estimated slopes of 5° to 20°. There wereoccasional rocks, 0.5 to 2.0 m in diameter, onthe sandy areas. Temperatures taken from thesubmarine in September 1968 dropped from25° C at 100 m to 22°, 18°, and 13° C at 150,200, and 300 m, respectively. Temperaturestaken by bathythermograph in April 1969were 20.5°, 18°, 14.5°, and 9° C, for thesame depths.

Traps and a few gill nets were also set offKaneohe and Haleiwa, Oahu. The bottom offKaneohe is steep but, judging from the typesof organisms collected and the frequent pres­ence of mud on the anchors, it is coveredmostly with sediment. The bottom off Haleiwais, in contrast to that of the other two areas,much gentler in slope. Except for occasionallow outcrops, the bottom at Haleiwa is sedi­ment-covered. About 160 traps were set be­tween 110 and 450 m off Kaneohe, most ofthem in November 1970; 46 traps were setbetween 110 and 220 m off Haleiwa in Apriland November 1970. In both areas, the trap­ping effort was about evenly distributedthroughout the depth ranges. One gillnet setwas made at 185 m over sediment-covered bot­tom off both areas. Gill nets were set at 110and 275 m over rocky areas near Kaneohe.

One series of deeper trap sets was made offKaneohe in November 1970. Sets of eight,four, four, and three traps per string were madeat 550, 640, 730, and 920 m, respectively.

RESULTS

DATE

14-15 Dec 196815-16 Dec 19689-10 Apr 19699-10 Apr 1969

10-11 Apr 196910-11 Apr 196928-29 Oct 196928-29 Oct 196928-29 Oct 196919-20 Jun 197119-20 Jun 197119-20 Jun 1971

DEPTH (m)

185-220185-245165-200225-310275-310200-275

365275185

39-4185-95

115-130

Fishes

Since the survey concentrated on depthsbelow 150 m, the lower limits of most shallowerwater species were not determined. Aulostomuschinemis, Caesioperca thompsoni, H olocanthttSarcuattlS, Heniochus acuminatus, Chromis vera­ter, and an unidentified balistiid were all seenfrequently down to about 150 m, but neverdeeper. Four species, Velifer multispinosus,Epinephelus quermtS, Pristopomoides micro­lepis, and Histiopterus typus, which apparently

TABLE 2

FISHES (BY FAMILY) AND DECAPOD CRUSTACEA (BY TRIBE) OBSERVED OR CAUGHT BELOW 150 METERS

DEPTH STANDARDTAXON METHODS RANGE (m) LENGTH (mm)

FishesOdontaspidae

Odontaspis ferox G (2) 185-310 1,600-2,230Carcharhinidae

Carcharhinus milbet·ti G(l) -185 1,200Sphyrnidae

Sphyrna lewini G (1) -275 865Squalidae

Squalus blainvillei G,T 165-320 300-500Centrophorus tesselatus G (10) 260-370 655-870Centroscyllium granulosum T(l) 920 310

DasyatidaeUrotrygon daviesi G (1) 370 650

ArgentinidaeGlossanodon sp. S 300

AteleopidaeAteleopus plicatellus S 370

MuraenidaeGymnothorax berndti S,G,T 150-225 300-940Gymnothorax nttttingi T 165-275 650-1,030Gymnothorax nudivomer T (1) 165 670Gymnothorax sp. G,T(4) 150-185 800-890

CongridaeConger oligoporus S(?),T(6) -365 54-127Congrellus aequoreus T (2) 275-640 210-265

OphichthidaeMuraenichthys macropterus T (1) 275 370

SynaphobranchidaeSynaphobranchus brachysomas T (1) 730 518

MoridaePhysiculus gt'innelli S*,G, T 165-320 110-280

PolymixiidaePolymixia japonica S,G 165-310 105-146

TrachichthyidaeH oplostethus mediterraneus G (2) 185 240Paratrachichthys sp. T (1) 185 28

HolocentridaeMYl'ipristis chryseres S*,G 90-175 165-190Ostichthys sp. G (5) 120-220 174-207

AntigoniidaeAntigonia steindachneri S, T (2) 190-275 50-105

SerranidaePseudanthias kellogi S 245-310

PriacanthidaePriacanthus alalaua G (3) 110-185 125-448Cookeolus boops S* -175 260

ApogonidaeApogon maculiferus T -150 45-95

CarangidaeSeriola rivoliana S -245 (1,000 )

EmmelichthyidaeErythrocles schlegelii S*,G (2) 120-255 235

LutjanidaeSymphysanodon typus S, G (1) 175-185 147Pristopomoides sieboldii T, G (6) -185 180-248

312

TABLE 2 (Continued)

DEPTH

TAXON METHODS RANGE (m)

Etelis marshi G,T 120-310Etelis carbunculus G (5) 120-185

ChaetodontidaeChaetodon modestus 5, G (2) 120-190

ParapercidaeN eopercis l'oseoviridis 5, T (4) 150-230

GempylidaePromethichthys prometheus 5, G (5) 90-360Epinula magistl'alis G (1) 185

CallionymidaeCallionymus caeruleonotatus 5 250-325

BrotulidaeBrotula multibarbata G (2) -220

5corpaenidaeSetarches remiger 5 310Plectrogenium nanum 5 380Pontinus macrocephalus 5,G 120-300

PeristediidaePeristedion engyceros G (1) 275

PlatycephalidaeBembradium roseum 5 325-335

TriacanthidaeHollardia goslinei T (1) 365

LophiidaeLophiomus miacanthus G (1) 365

ChaunacidaeChaunax umbl'inus 5 330

Decapod CrustaceaPenaeidea

Penaeus marginatus G,T 110-220Caridea, Pandalidae

Plesioneka martia G,T 110-275Plesioneka ocellus T (7) 110-150Plesioneka ensis T (1) 365Parapandalus sp, T 110-220H eterocarpus ensifer G,T 150-730Heterocarpus laevigatus T 365-730

Caridea, OplophoridaeAcanthephyra eximea T (16) 550-920

5cyllarideaScyllarus timidus 5,T,G 110-185

BrachyuraLyreidus tridentatus G,T 185-320Notopoides latus G (2) 185Notosceles sp, G (3) 130Thelxiope orientalis G,T 110-220H omala japonica 5,G,T 165-375Randallia distincta 5,G 275-310Mursia hawaiiensis G 165-365Cyrtomaia smithi 5,G,T(5) 255-360Dairoides kusei G,T 120-200Portunus sanguinolent!ls G,T -185Micropanope sexlobata T (1) 165

STANDARD

LENGTH (mm)

145-303187-345

90

75-105

210-222310

300-427

174-307

218

42

140

(25)

35-46

8-2513-15

2510-1611-3413-55

12-46

25-39

50-6530-3220-3028-5822-5037-4234-3845-5449-6450-80

14

NOTE: The second column gives methods-S, submarine observation; S', submarine observation with at least one speci­men being collected from in Jilu poisoning; G, gill net; T, trap, Where fewer than 10 specimens were collected, the totalnumber is given in parentheses, The third column gives depth or depth range in meters; for species known to occur substan­tially shallower than 150 m, only the deepest record is shown. The fourth column gives standard length of fishes or carapacelength of crustaceans in millimeters; numbers in parentheses were estimated from the submarine.

313

314

do not occur above about 75 to 100 m werecollected at 110, 110-135, 110, and 110 m,respectively, but were neither observed norcollected deeper. These species are apparentlyrestricted to a rather narrow depth range. Otherspecies taken in gill nets at 90-110 m wereOstichthys pilwaxii, Priacanthus meeki, Mul­loidichthys pflttgeri, Sarda orientalis, and Nasohexacanthus.

Fishes collected or seen and identified below150 m are given in Table 2. Other, distinctlydifferent species were observed from the subbut not definitely identified. These included oneor more lutjanids (probably Aphareus rutilans)observed down to 330 m, one or two speciesof scorpaenids down to 300 m, and holocentridsand priacanthids down to 225 m. A smallchaetodontid and a serranidlike species ob­served between about 150 to 175 m wereprobably Hemitaurichthys sp. and Odontanthiassp., respectively. Several other species observedbetween 150 to 200 m are almost certainlyundescribed and unfortunately uncollected.Two species of congrids collected from 330 m,an ophichthid from 330-365 m, and a ma­crourid from 730 m are at present unidentifiedand not included in Table 2.

The most abundant fish in the depths sur­veyed was Polymixia japonica. Large schools of100 or more were seen just above the bottomduring the day, mostly between 240 and 300m. At night up to 20 were caught per 30 mlink of 1.5-inch-mesh gill netting. They werecaught in large numbers as shallow as 185 m,which suggests that this species migrates up andinshore at night. Polymixia was the only speciesthat did not regularly disgorge stomach con­tents on the way up. Of 31 specimens withfood, 17 had eaten shrimp, mostly benthiccarideans; 12, fishes; five, crabs; and four,small cephalopods, probably octopi. Isopods, astomatopod, a mysid, and a trochophore larvawere also recorded. Polymixia, judged by itsabundance, is probably a major consumer ofsmall benthic organisms in this depth rangeand is likely an important forage fish for largerpredators there.

Lutjanids and muraenids were the mostabundant predatory fishes. The most commonlutjanid seen from the sub during the day wasprobably Aphareus rutilans; it was not collected

PACIFIC SCIENCE, Volume 26, July 1972

in the gill nets at night. Etelis marshi was themost commonly caught predator in the gill nets.Muraenids appeared to be very abundant in therocky areas between 150 to 200 m off BarbersPoint, but were rarely caught over sediment­covered bottoms off Kaneohe or Haleiwa.Traps set off Barbers Point caught as many asnine individuals overnight. The eels almostcertainly excluded other organisms from thetraps and biased results. Many smaller Crustacea,e.g., Scyllarus timidus and the pandalid shrimps,were caught rarely or only in gill nets offBarbers Point but were quite common in. trapsset off Kaneohe and Haleiwa.

Decapod Crustacea

Of the crabs, only Homala, Randallia, andCyrtomaia could be identified from the sub.These species and Mttrsia were not well sam­pled by traps and may occur below the deepestgillnet set and below the sub's range. Theranges given for other species are probablyvalid and indicate that most occur within thedepths surveyed. Notopoides latus and Noto­sceles sp., in contrast to most raninids, appearto prefer rocky bottom; they were caught onlyin gill nets on steep rocky bottoms off BarbersPoint and never in the same depth range oversediment-covered bottoms elsewhere.

Heterocarpus ensifer was by far the mostabundant and widespread shrimp. Between 275and 365 m during the winter months, catchesaveraged 1 to 2 kg/trap and sometimes ex­ceeded 10 kg. Data on depth and seasonalchanges in abundance, sex ratio, etc., for thisspecies and other pandalids will be presentedin a separate, more detailed report.

Plesioneka martia and Parapandalus sp. werealso taken frequently but were most abundantat 150 to 200 m and 110 to 180 m, respectively.Between 240 and 330 m a few groups of dis­tinctly smaller shrimps were seen from thesubmarine. Apparently the larger species areeither inactive during the day or move intoshallower depths only at night.

DISCUSSION

In the present survey, shallow-water reeffishes were noted less frequently and not asdeeply as recorded by Brock and Chamberlain

Deep Benthic Fishes and Decapod Crustacea in Hawaii-CLARKE 315

(1968). Rather than being "essentially a se­lected portion of the near shore fauna," thefishes observed and collected between 150 and200 m included deeper, as well as shallower,water forms and a few species apparently re­stricted to this depth range, e.g., C. modesttts,Ostichthys sp., and probably the Gymnothoraxspp. For the most part, the crustaceans caughtin this zone either were also found substantiallydeeper or occurred only within the zone, i.e.,they were not an extension of the shallow­water fauna.

Of the 47 species of fishes taken or seenabove about 365 m, six are known species notpreviously recorded from Hawaii: Odontaspisferox, Centrophorus tesselatus, Urotrygondaviesi, Mttraenichthys macropterus, Hoploste­thus mediterraneus, and Epinula magistalis.Paratrachichthys sp. may prove to be a newspecies and is definitely unrecorded in Hawaii.(The latter species and Urotrygon have alsobeen taken in recent trawling surveys, P. J.Strauhsaker, personal communication.) Gymno­thorax sp., Ostichthys sp., two congrids, andan ophichthid appear to be undescribed. Thetwo specimens of Chaetodon modestus repre­sent the first Hawaiian record of the speciessince Jordan (1922) described a 5-cm indi­vidual as Loa excelsa (Heniochus exselsa ofsome authors). W. E. Burgess (personal com­munication) has placed excelsa in the synonymyof modestus, a species described from Japan.

Of these 13 undescribed or unrecorded spe­cies, the gill nets collected nine species; sevenwere collected only in gill nets. Several otherforms taken in gill nets have been recordedrarely in the past, e.g., Symphysanodon typus,Velifer multispinostts, and Histiopterus typttS.Not only did the gill nets collect species missedby previous surveys, but also species not seenfrom the submarine. Of 28 species collected bygill nets, only 10 were definitely identified fromthe submarine.

The gill nets were effective in collecting newor rare species, in part because they sampledsteep, rocky bottoms where other methods,particularly trawls, are notably unsuccessful.They also collected species which, because oftheir size or behavior, are not successfullysampled by other means. Some of the largerfishes like Odontaspis, Centrophorus, and

Epinula can probably avoid a trawl and likelyretreated from the presence of the submarine.Hoplostethus and Ostichthys are probably cryp­tic forms and either withdrew into the rockson the sub's approach or were not active duringthe day.

Of the 22 fishes identified from the sub, 10were gillnetted. The species that were missedwere mostly either eels or species seen only afew times over open sand. Eels and some ofthe latter were captured in traps, but ninespecies were not collected by any means. Mostof the sand-bottom species are frequently takenby trawls. There was a minimum of 11 speciesseen but not identified from the sub. Of these,only C. modestus was collected. The otherspecies all occurred in steep, rocky areas be­tween about 175 and 200 m. In situ poisoningcollections or possibly traps submerged forlonger periods would seem to be the onlymethods to collect such species.

All of the shrimps found above 365 m weretaken by traps, and the two most abundantspecies, Heterocarpus ensifer and Plesionekamartia, also were taken frequently by gill nets.The other Plesioneka species were caught rarelyand only in traps. Parapandalus sp., the firstrecord of this genus in Hawaii, was taken quitefrequently. Its absence from previous surveysis thus somewhat puzzling. Its frequent capturehere may be simply due to extensive use ofsmaller-mesh traps.

The slipper lobster, Scyllartts timidus, hasbeen previously recorded in Hawaii from onlyone specimen, but it appears to be common.Only one individual was seen from the sub,but several were caught over rocky areas bygill nets. Off Haleiwa, where the bottom intheir depth range is smooth and sediment­covered, up to 10 were taken in a single trap.Two other scyllarideans, Scyllaroides squamoSttsand Panulirus marginatus, were collected asdeep as 110 m, but no deeper.

The gill nets proved quite effective for crabsas well as fishes. Of the 10 species collected,only Micropanope sexlobata (one specimen)was caught by trap only. Three of the remainingspecies were taken only by gill nets and, exceptfor Portunus sanguinolentus, the others weretaken nearly as frequently as in traps. Threespecies, Notopoides latus, Thelxiope orientalis,

316

and Dairoides kusei, have not been recordedfrom Hawaii, and Notosceles sp. is apparentlyundescribed (}. S. Garth, personal communica­tion). All four were caught over steep rockybottoms that had not been well sampled pre­viously.

CONCLUSION

The rather large number of undescribed andpreviously unrecorded species collected duringthis survey suggests that further use of differentcollection methods, particularly gill nets, inother areas would be of great interest to tax­onomists and zoogeographers. Trawling sur­veys and local fisheries have been the usualsources of data for many parts of the world,but it appears that these sources consistentlymiss or only occasionally collect certain typesof organisms. In future studies, investigatorsshould attempt to use as many methods aspossible to collect specimens, and zoogeograph­ers should at least consider what sorts ofspecies were likely missed by the methodsused.

ACKNOWLEDGMENTS

I was accompanied on submarine dives byP. J. Struhsaker, V. E. Brock, and G. I. Murphy.During fishing operations I have relied heavilyon the assistance and experience of T. Okamura.Patricia J. Wagner capably assisted in all phasesof the work. I also thank W. S. Scholtz and thecrew of the R.V. Teritu, Ed and DannyBilderback of the Valiant Maid, and WilliamYee Hoy of the Ola, for their cooperation.

I thank J. S. Garth, R. K. Johnson, J. E.McCosker, S. Springer, and D. A. Ziemann forassistance in identifying specimens. I am par­ticularly grateful for the assistance, interest,and cooperation of J. E. Randall and P. J.Struhsaker.

The original impetus for this program camefrom V. E. Brock.

APPENDIX

NOTES ON UNCERTAIN OR TENTATNESPECIES NAMES

1. Glossanodon sp. was probably identical witha presently undescribed species frequently

PACIFIC SCIENCE, Volume 26, July 1972

taken in bottom trawls (P. J. Struhsaker,personal communication).

2. Gymnothorax mlttingi Snyder has beenplaced in the synonymy of G. pictus byFowler (1928) and in the synonymy of G.meleagris by Gosline and Brock (1965).Fresh material taken during this survey hasrevealed that nuttingi is a valid species (}.E. Randall, personal communication).

3. Gosline and Brock (1965) synonymizedthe muraenids Gymnothorax goldsboroughiJordan & Evermann and G. xanthostomusSnyder with G. meleagris. These names,however, are synonyms of G. nudivomer(Gunther), as indicated by Fowler (1928)(}. E. Randall, personal communication).

4. Gynmothorax sp. in Table 2 is undescribed(}. E. Randall, personal communication).

5. Ostichthys sp. is undescribed. It representsone of two species of the genus in theHawaiian Islands. The other is O. pilwaxii(Steindachner), erroneously placed in thesynonymy of japonicus by Fowler (1928)and Gosline and Brock (1965) (}. E.Randall, personal communication).

6. Seriola rivoliana is used here instead of S.dumerilii (Gosline and Brock, 1965) basedon personal communication to J. E. Randallby F. J. Mather III.

7. Plesioneka martia and P. ocellus, as usedhere, are probably identical with the usageby Rathbun (1906), but differ from de­scriptions by de Man (1920). P. martiafrom Hawaii bears about eight spines on theanterior part of the rostrum. For P. ocelltlsfrom Hawaii, the second pair of walkinglegs is of equal length.

LITERATURE CITED

BROCK, V. E., and T. C. CHAMBERLAIN. 1968.A geological and ecological reconnaissanceoff western Oahu, Hawaii, principally bymeans of the research submarine "Asherah."Pacif. Sci. 22(3) :373-394.

DE MAN, J. G. 1920. The Decapoda of theSiboga Expedition. Part IV. Siboga Exped.,mono 39a 3:1-318.

FOWLER, H. W. 1928. The fishes of Oceania.Mem. Bishop Mus. 10. 540 p.

GILBERT, C. H. 1905. The aquatic resources of

Deep Benthic Fishes and Decapod Crustacea in Hawaii-CLARKE 317

the Hawaiian Islands. Part 2. The deep-seafishes. Bull. U.S. Fish Comm., 1903, 23:577-713.

GOSLINE, W. A. 1965. Vertical zonation ofinshore fishes in the upper water layers ofthe Hawaiian Islands. Ecology 46(6) :823­831.

GOSLINE, W. A., and V. E. BROCK. 1965.Handbook of Hawaiian fishes. Univ. HawaiiPress, Honolulu. 372 p.

GOSLINE, W. A., H. L. MOORE, and Y.YAMAGUCHI. 1954. Fishes killed by the 1950eruption of Mauna Loa. 1. The origin and

nature of the collections. Paci£. Sci. 8 (1) :23-27.

JORDAN, D. S. 1922. Description of deep-seafishes from the coast of Hawaii, killed by alava flow from Mauna Loa. Proc. U.S. Nat.Mus. 59:643-658.

RATHBUN, M. J. 1906. The Brachyura andMacrura of the Hawaiian Islands. Bull. U.S.Fish Comm. Pt. 3:827-930.

STRASBURG, D. W., E. C. JONES, and R. T. B.IVERSON. 1968. Use of a small submarine forbiological and oceanographic research. J.Cons. into Explor. Mer 31(3) :410--426.