Nippon Suisan Gakkaishi 54(7), 1149-1154 (1988)

Culture of the Palinurid elephas from Egg Stage to Puerulus

Jiro Kittaka* and Eishi Ikegami* (ReceivedNovember 26, 1987)

The first complete phyllosoma culture of Palinurus elephas was accomplished in the laboratory following the successful culture of lalandii and a hybrid of Jasus. Egg-bearing females were usually found in tanks in October and November, and hatching occurred in the following spring. About 3,000 stage I phyllosoma were cultured at 17-19•Ž, being fed with nauplii of Artemia at the intial stages and Mytilus edulis at advanced stages. The phyllosoma advanced to stage IV after 41

days from hatching. An individual was estimated to molt another four times to reach the final

phyllosoma stage. Metamorphosis into the puerulus stage occurred 132 days after hatching. The large size at hatching and the short time to metamorphosis are characteristic of the phyllosoma of this species. The behaviour of the Palinurus elephas puerulus was significantly different to that of Jasus spp.; Palinurus elephas stretched the five pairs of pereiopods wide during swimming and also while on the bottom.

A cold temperate palinurid species, Palinurus Materials and Methods elephas occurs along the northeast Atlantic coast and supplies locally important fisheries resources. Materials P. elephas were obtained in Bretagne, Research on biology of this species was carried out France and in Galway County, Ireland. The by Bouvier,1,2) Gurney,3) etc. in 1910-1920's. first shipment came from Carna, Ireland in Bouvier1,2) described phyllosoma stages for P. August 1980. The second and third shipments elephas and supposed that larval development came from It d'Hout, France in October 1981 and would be completed in 3-4 months. Also, October 1986. The were introduced into Berry6) pointed out that Palinurus delagoae of a FRP tank with slow running sea water and South African species hatched out first stage aeration. Water temperature ranged between phyllosomas in a more advanced state of develop approximately 10•Ž in winter and 20•Ž in summer. ment. He supposed that larval P. delagoae might have a relatively short larval life.6) If their Mytilus edulis were given daily as food. Egg hypotheses are correct, genus Palinurus would be bearing females were found almost every year after 1982. suitable species for aquaculture. However, no experiments have been published on the larval A total of 3 females and 2 males in 1984 and culture of this species. The authors used P. 1985 and 9 females and 2 males in 1986 were elephas for spiny culture experiments used for mating experiment. All females in 1984 and 1985 and 6 females in 1987 were found to be at Sanriku because of its low water temperature bearing eggs. Rearing experiments for phyl requirement. Rearing from egg to the pureulus losomas were commenced in 1985. stage has already been accomplished for a cold temperate species of the Southern Hemisphere, Methods ,4) and a hybrid between Jasus Between 1,000 and 5,000 phyllosoma larvae novaehollandiae and .5) The same were introduced into a 100l circular tank on the culture method4,5) was applied for P. elephas. day of hatching. Sea water treated with a 5ƒÊ This paper deals with the first larval culture ceramic filter and ultra-violet sterilizer was sup of P. elephas. eplied at the bottom through a recirculating system.

Cultured marine Chlorella and the diatom Nitshchia sp. were added to the culture tank.

* School of Fisheries Sciences, Kitasato University, Sanriku 022-01, Japan (‹k•‚“ñ˜Y,’r•ã‰hŽi:–k—¢‘å 1150 Kittaka and Ikegami

Water temperature was maintained at approxi Larval Rearing mately 17-20•Ž. The larvae were fed with a Results of the phyllosoma rearing experiments combination of Artemia nauplii, adult Artemia and are shown in Table 1. A total of six experiments

Mytilus edulis. Water temperature, salinity, pH, (No. 1-6) was done in 1985-1987. The ex density of Chlorella and the diatom, rate of water periment No. 5 was continued during entire phyl exchange and amount of food given were measured losoma stage, while the others were discontinued daily. within 22-56 days due to heavy mortality. The average intermolt interval was 11.2-15.5 days for the initial three stages. Survival rates Results were very low during these stages. After the Reproduction fourth stage, monitoring individual stages became The annual cycle of reproduction for P. difficult due both to decreased numbers of indi elephas is shown in Fig. 1. viduals and the wide range of stages. Molting for males occurred mainly from No Experiment No. 5 began on 19 March 1987 with vember to February, prior to the molting of 3,000 first stage phyllosomas. Only one individual females which was mainly from March to May. survived and it molted into the final stage phyl Although mating behaviour has not yet been ob losoma on 9 July. This individual metamor served, mating probably occurs between Septem phosed into the puerulus stage on 29 July, 132 ber and November because egg bearing females days after hatching out. The intermolt interval were first found in that season. Egg-hatching of the final stage was 20 days. Assuming that the occurred mainly from February to May, with intermolt intervals is approximately 15.5-20.0 ocassinal hatching in January. Approximately (average 17.8) days during the period from the 40,000 phyllosomas hatched from each female. fourth to the final stage, this individual is estimated The low number is probably due to the low to have molted about 4 times over the 71 day fecundity of the species. P. elephas carries period (=132 days minus 41 days from the first large-sized but low numbers of eggs compared to the fourth stage minus 20 days during the final with species of the genus Panulirus and Jasus.7) stage). The final stage was estimated at the

Fig. 1. Reproductive cycle of adult Palinurus elephas in the laboratory at Sanriku. Monthly averge water temperature is shown with closed circles on a curve. Molting for

males, molting for females, egg-bearing, and hatching are shown with upward arrow heads

(•£), downward arrow heads (•¥), open circles (•›), and downward arrows (•«), respectively. Number of female and male was 4 and 2 in 1982 and 1983, 3 and 2 in 1984 and 1985, and 9 and 2 in 1986. Complete Phyllosoma Culture of Palinurus elephas 1151

Table 1. Rearing experiments for phyllosoma of Palinurus elephas

No. of exp. 1 2 3 4 5*1 6 Avg. Intermolt days Stage I 16 17 9 15 8 9 12.3 II 10 14 14 11 7 11.2 III 8 10 22 22 15.5 ? *2 Final 20 20.0 Puerulus Initial No. 5,000 10 1,000 1,000 3,000 4,000 Rearing days 41 56 22 28 132 50 Survival No. 6 1 0 0 1*1 0 Date of May 18 May 19 Feb 6 Mar 22 Mar 19 May 5 beginning 1985 1985 1986 1986 1987 1987 *1 Complete development from egg stage to puerulus. *2 The fifth and sixth stages were observed on dead animals 89 and 98 days after hatching , respectively. eighth instar. The stags will be confirmed pre lalandii.4) cisely through continuing rearing experiments.

Rearing Conditions

Larval Stages Water quality and feeding for the period from The first and sixth phyllosoma stages and the the first stage phyllosoma to the pureulus stage is puerulus are shown in Fig. 2. Staging was not shown in Fig. 3. possible after the sixth stage because only one Water temperature was maintained at approxi individual survived. mately 17-18•Ž for the initial 70 day period and The first stage phyllosoma of P. elephas at approximately 19•Ž for the following 20 days was an average 2.8mm in total length (Fig. 2. A period. These water temperature are suitable and D), which is much larger than that of other for culturing Jasus phyllosomas.4,5) At 17-18•Ž, species (Panulirus japonicus,8) J. lalandii,9) and early stage phyllosomas of P. elephas molted after J. edwardsii10)). The phyllosoma of P. elephas rather short but irregular intervals. At 19•Ž, has several unique features. In the first stage, the molting was delayed for the surviving individual of exopodite of the third pereiopod is an elongated experiment No. 5 until the water temperature was segment, while it appears as only a bud in other lowered to 17-18•Ž. species. The uropods are indicated as swellings Salinity and pH were similar as recorded in the in the second stage and their cleavage begins in culture tank for Jasus.4,5) Feeding was mainly the third stage. In the fourth stage, the uropod with Artemia in early stages and Mytilus edulis in development is similar to that of the ninth stage mid- to late stages. The phyllosomas of P. phyllosoma of other species. The natatory setae elephas were able to prey adult Artemia at early appear on the exopodite of the fourth pereiopod stage. Density of Chlorella ranged between 7•~106 in the fifth stage. In the sixth stage, the fifth and 9•~106 cells/ml in early and mid-periods of the pereiopods elongate beyond the distal end of the experiment, but was decreased in the late period. telson (Fig. 2. B and E). The development of the After the midperiod water of the culture tank abdomen and telson at the sixth stage was similar was exchanged infrequently. This might have to that of the late phyllosoma stage of Panulirnsa8) had an unfavourable effect on water quality in and Jasus.9,10) However, gill buds were not the culture tank, particularly at the higher found at this stage. water temperature of 19•Ž mentioned above. The most distinctive feature of the phyllosoma The antennules and antennae became malformed of P. elephas is that the second pereiopods, which at the molt into the final stage phyllosoma. are shown by arrows in Fig. 2, is the most elongate throughout the phyllosoma stage. In the case of Behaviour of Puerulus P. japonicus8) and J. lalandii,4) the third pereiopod The phyllosoma metamorphosed into the pu is more elongate at the initial stage, with the erulus on 29 July 1987 although malformation fourth pereiopod becoming most developed for was found as seen in the final stage phyllosoma P. japonicus8) and the fifth pereiopod for J. (Fig. 2. C). The puerulus was kept in a tank in 1152 Kittaka and Ikegami

Fig. 2. Larval stage of Palinurus elephas cultured in the laboratory. A. Phyllosoma stage I (5 dsys after hatching, total length 2.8mm). B. Phyllosoma stage VI (95 days after hatching, total length 9.5 mm). C. Puerulus (7 days after metamorphosis, total length 10.0mm). D and E. Abdomen of the phyllosoma stage I and VI, respectively. F. Cast molt of the puerulus (15 days after metamorphosis). Arrow indicates the second pereiopod.

which the water was circulated at several cm/sec. elephas usually streched the 5 pairs of pereiopods Three days after metamorphosis, the puerulus wide, lifted the cephalothorax, then supported its sometimes attached to the end of a piece of PVC abdomen by beating the well-developed pleopods. pipe with its pereiopods but continued to beat Feeding behaviour was not confirmed as in the its pleopods. The clinging posture of the puerulus case of the puerulus of Jasus.4,5) while still using its pleopods was remarkably dif Although the puerulus was active, it died during ferent from that of Jasus.4,5) The puerulus of P. the molt 15 days after metamorphosis (Fig. 2. F). Complete Phyllosoma Culture of Palinurus elephas 1153

period (132 days in this experiment) and smaller number of stages (estimated to be 8 molts in this

experiment) compared with the majority of other

species .4,5,8)

However, the number of larvae cultured to a

late stage in our experiment was small, and the

discrepancy between the present result and Bou

vier's description on the number of phyllosoma

stages needs to be examined through further

experiments.

Survival rate for P. elephas was very low in the

first stage even though the phyllosomas were large. Water temperature was maintained at 17-

19•Ž as for J. lalandii.3) High mortality and

malformation of P. elephas phyllosomas may

have been because this species requires rather a

lower water temperature than Jasus. The puerulus

cultured in our experiment was much smaller than

that described by Bouvier.1,2) Although the reason

was not clear, one possibility was that there was

less food consumed in the short intermolt in

tervals at the higher water temperature in our

experiment. Combined effects of food availabili Fig. 3. Environmental and feeding condition in the ty and water temperature upon the intermolt rearing tank for the phyllosoma of Palinurus elephas during the period from March 19, 1987 intervals and the growth gain for phyllosomas to July 29, 1987. also need to be examined. Feeding amount indicates total amount of Another interesting factor which may effect feed given daily per tank. lower survival rates for P. elephas under laboratory conditions is the relative proportions of the

P. elephas puerulus looks to have very long leg appendages, with the second pereiopod being the compared with those of Jasus.4,5) most elongated. Phyllosomas of Jasus were often observed swimming with the most elongated fifth Discussion pereiopods directed backward, which makes the fifth pereiopods effective in catching food particles Mercer* reviewed the studies on the develop on their tips. Such swimming posture was not ment and distribution of the larvae of P. elephas observed for P. elephas. off the west coast of Ireland. The first stage P. elephas phyllosoma developed in the labora phyllosomas were found in the plankton in tory is significantly different to that of the Panu May to early July. The juveniles (Total length: liruse6) and Jasus4,5) species so far investigated. 25-50mm) were found in reef crevices in late This may be because the eddy current circulations June to August. Therefore, it was considered off the west coast of Ireland, which retain the that P. elephas completed its larval life in about phyllosomas of P. elephas, are smallerscale com

10-12 months as Jasus4,5) and Panurilus8). pared with the scale of the current patterns in the On the contrary Bouvier1,2) and Berry6) sup oceans which retain the phyllosomas of Panulirusu11) posed that larval development for genus Palinurus or Jasus.10) P. elephas was also unique in would be shorter. This was probably associated that the animals were frequently seen spreading with both the larger egg size and longer incu appendages and lifting their cephalothorax from batory period of Palinurus. These contrasting puerulus stage to adult. Under laboratory con hypotheses have been clarified by our culture ditions, adult P. elephas12) are usully found on the experiment; phyllosoma of P. elephas metamor top of rocks while J. lalandii13) and P. japonicus14) phosed into puerulus after a relatively short are found in shelters.

* J .P. Mercer: Studies on the spiny off the West Coast of Ireland with particular referene to Palinurus elephas. Ph.D. Thesis, National University of Ireland, University College Galway, 1973, pp. 331. 1154 Kittaka and Ikegami

Although culturing phyllosoma has proved very References difficult, it has generally been believed that rearing pueruli collected in the wild to the juvenile stage is 1) E. L. Bouvier: Nature, 91 (2286), 633-634 rather easy as already shown for P. japonicus by (1913). Kinoshita15) and for P. cygnus by Chit 2) E. L. Bouvier: C. R. Acad. Sci., Paris, 157, tleborough.16) However, our rearing experiments 457-463 (1913). 3) R. Gurney: Discovery Rep., 12, 400-440 (1936). showed mortality in the puerulus stage, not only 4) J. Kittaka: Nippon Suisan Gakkaishi 54, 87-93 for P. elephas but also for J. lalandii4) and a Jasus (1988). hybrid.5) This may suggest both environmental 5) J. Kittaka: Nippon Suisan Gakkaishi 54, 413- and nutritional requirements are significantly dif 417(1988). ferent between the phyllosoma and early puerulus 6) P. F. Berry: Invest. Rep. Oceanogr. Res. Inst., stages. Research should be undertaken to develop 34,1-44 (1974). a culture method for the early puerulus stage as 7) G. R. Morgan: in "The Biology and Manage well as to improve survival rate at early phyl ment of Lobsters" (ed. by J. S. Cobb and B. F. losoma stage. Phillips), Vol. 2, Academic Press, New York, 1980, pp. 199-200. 8) M. Inoue: Nippon Suisan Gakkaishi, 44, 457- Acknowledgements 475(1978). 9) B. I. Silberbauer: Invest. Div. Sea. Fish. S. Afr., The authors wish to express their sincere thanks 92,1-70 (1970). to Dr. J. P. Mercer, Shellfish Research Laboratory, 10) J. H. R. Lesser: N. Z. Mar. Freshwater Res., Ireland, Dr. H. J. Ceccaldi and Dr. Y. Henocque, 12, 357-370 (1978). Station Marine d'Endoume, France for arranging 11) B. F. Phillips and P. S. McWilliams: Can, J. shipment of experimental lobsters. The authors Fish, Aquat, Sci., 43, 2153-2163 (1986). are indebted to the following former students of 12) J. Kittaka: Rep. M. E. C. S. Grant-in-Aid the School of Fisheries Sciences, Kitasato Uni Overseas Sci. Surv., No. 404152 and 504347," versity, for their assistance during the preparatory 1-77 (1981). 13) J. Kittaka: Rep. M. E. C. S. Grant-in-Aid experiments for this study: Mr. M. Igarashi, Mr. Overseas Sci. Surv., No. 56042009, 57041052 H. Igusa, Mr. A. Yahata, and Miss H. Akiyama. and 58043052, 1-118 (1984). The authors thank Dr. J. D. Booth, Fisheries 14) Y. Ogawa: Marine Science/Monthly, 12, 858- Research Center, New Zealand for his review of 863 (1980). (in Japanese). the manuscript. This work was supported in 15) T. Kinoshita: Zool. Mag., 46, 391-399 (1934). part by a Grant-in-Aid for Overseas Scientific 16) R. G. Chittleborough: Aust. Fish., 33, 4-8 Survey from the Ministry of Education, Culture (1974). and Science.

Nippon Suisan Gakkaishi: Formerly Bull. Japan. Soc. Sci. Fish.