Bull. %001. Surv. India, 1 (2) 171-175, 1978

A PARTHENOPID , ZEBRIDA ADAMS1IWHITE, 1847 INHABITING INTBRSPACES OF SPINES OF THE , SALMAC1~ VIRGULATA. L. AGASSIZ, 1846

A. DANmL AND S. KRISHNAN

Marine Biological Station, Zoological Survey of India, Madras

ABSTRAC't

Association of a parthenopid crab, Z ,fwia adamsii White with the echinoid S.'mt.Jm virgulaltJ L. Agassiz, ezisting at 18-20 metres depth along the Madras sea coast is reported. Systematics and distribution of tbe echinoid bosts and its associates are noted. Z. adamssi is recorded for tbe first time from the Bay of Bengal. Field and laboratory observati ons revealed that the movements of tha era1\. in between the spines of the echinoid host cause minor damages to the spines at base.

INTRODUCTION field and in the laboratory. In the same trawling ground two other species of sea Whilst collecting marine fauna in the urchins i. e., Salmacis bieolor L. Agassiz inshore regions of the Madras coast, o~ board 1846 and Temnopleurus toreumaticus Leske, R. V: Chota Investigator during December 1915 1778 also occurred rarely. to August 1977, an interesting relationship between t I, e parthenopid crab, Zebrida OBSERVATIONS adamsi; and host sea urchin, Sa lmac is vi,gulata was observed. The details of this Field observations : Examination of 1171 association together with some experimental specimens of the sea urchin, S. virgulata laboratory observations on the associates, and during the period December, 1975 to August, previous record s of this species of crab from 1917 (Table 1) yielded five males and two sea urchins are presented in this paper. females of the parthenopid crab, Z. adamsii. Among the two females, only one, examined MATERIAL in October, 1976 was found to be ovigerous. It was also noted that the two other species of Salmacis l~irgulata were obtained by the sea urchins namely, S. hie%r and T operating the bottom trawl net opposite to toreumaticus which were not common in the the Madras University area, where this species sea area sampled (9 specimens of the former of sea urchin occurred in abundance. The host and 6 specimens of the latter were collected species were examined for the presence of the during the entire period of 21 months) did parthenopid , Z. adamsii both in tile nQt har\lour an¥ specimen of Z. adamsii. 172 Bulletin of the Zoological Survey o/Indill

TAB~lt 1. Months of collection with number of host urchins examined and details of the crustacean associate --- S. No. Year~ No. of Host No. of crabs Sex of the Width of the month (S.vit'gulata) (2'. adamsii) crustacean carapace examined observed associate (in mm.)

1. December, 1975 25 1 ~ 8.5 2· January, 1976 58 3. February 42 4. March 120 5. April 220 2 c!cf 7.0 6. May 85 7. June 62

8. July 93 2 ~ & ~ 4.0 & 7.0 9. August 108 10. September 76

10. October 31 1 ~ (oviger9us) 11.0 12. November 18 13. December 28 14. January, 1977 15. February 34 - 16. March 47 1 & 8.0 17. April 18. May 19. June 20. July

21. August 12' . -. - -_ t._ Total 1171 7

The presence of Z. adamsi; on the tes~ of March, 1977 were kept in separate aquarium s. "rgu/ala was mainly towards the oral end. tanks containing running sea water in the In one association, a visible damage could be laboratory. At the bottom of the tank some observed on the spines of the host, suggesting sand and pieces of shells and rocks were that the crab which had settled on the test arranged to simulate the conditions of the a few weeks earlier had cut the base of the inshore region. The crab was carefully spines (Plate IV ~a). dislodged and released in the same container. Within one hour the crab had resettled in Laboratory ex periments : Two sets of the same spot from which it was dislodged. asso~iation~ ol>tained in July 197~ an~ ~t Wa$ al~9 n9t~~ tlt~t ~Q ~~llnase to tb~ DANmL & KlllSHNAN: On Par,benopld crab 173

spines of the host occurred during the two Travancore. Its recorded bathymetric range weeks of laboratory rearing of the associates is from 10 to 55 metres (Suzuki and Takeda, in the tanks. 1974 ).

S,,',mGtle "ote and distribution of the crus­ Systematic note tJnd distribution of the echinoid 'Geea" MaDei".te host:

A review of literature of the crabs of the i. genus Z,b,ida of Indo-west Pacific region Of the two species of Sa/mac is e., and S. hieolor the former can be reveals that there were two species, i. e., S. vi,gulata identified externally by their purple colour of Z. Qdamlil White, 1847 and Z. paueidentata Flipse. 1930 (Serene, 1968). However, Suzuki the primary spines and the high test. Each aDd Takeda (1974) have questioned the validity ambulacral plate bears primary tubercle. The of the species Z. paucidentata. From their interambulacral plates are separated by distinct sutures. In S. hie%r, the primary spines are J)oint of view, it could be that ~. paucidentata . which as recorded by Rauthbun (1910) could more or less bright red, with 4-7 narrow be juvenile form of Z. adams;;, and as such yellowish bands. The small spines are red. Z. paue;dentata is to be considered as a The primary tubercles occur on every second synonym of 2. adamsil. The genus Zebrida amhularcal plate. T. tarumaticus can be is, therefore, a monotypical genus represented identified by their larger spines (compared to by Z. adtUn8ii. the diameter of the test), which are brown in colour with light to deep irregular bands. fhis Crustacean species is distinguished by The coronal plate bears 1 to 3 primary tubercles. the delicate madder pink of the body with darker (liver coloured) parallel longi- .. tudinal bands and alternating streaks on S. 'Virgu/ata has so far been recorded from the carapace (Plate lV -b). The carapace is the following shallow-water areas of the Indo­ subrhomboidal with the flattened dorsum, west Pacific regions : Ceylon area, Bay of the rostrum being formed by two large laminar Bengal, East Indies, Phillippine Island, China teeth. 'I'he orbit is circular with the inner and Southern Japan (Clarke and Rowe, 1971). canthus filled by part of the antennal peduncle. The antennule is folded very s. hieolor has so far been recorded from obliquely. The cheIipeds are stout, equal and the following shallow-water areas of the Indo­ short, being armed with laminar teeth. The west Pacifc regions : Isles of West Indian ambulatory legs are strongly compressed and Ocean, Mascarene Island, East Africa and subchelate with the propodi and dactili. The Madagascar, Red Sea, West India and male abdomen is composed of seven segments. Pakistan, Maldive area, Ceylon area, Bay of The first male pleopod is shaped like the Bengal, East Indies, PhiI1ippine Island, China interrogation mark (Plate 1V -c). The colour and· Southern Japan. T. toreumaticus has so pattern and frontal and laminar teeth, and far been recorded from the following shallow­ the first male pleopod are characteristic of water areas of the Indo-west Pacific regions ; this species. East Africa and Madagascar, Red Sea, South East Arabia, Persian Gulf, West India and ~. oiamsii has so' far been recorded from Pakistan, Maldive area, Ceylon area, Bay Japan, Borneo, Gulf of Siam, 'rorres Strait, of Bengal, East Indies, North Australia, Sri Lanka, Gulf of Mannar and coast of Phillippine Island, China and Southern Japan ,Bu,lletln 0/ the Zoological Survey of India

DANUIL & KIUSHN AN PLATE IV

a-L: fbrith' ,adUl1Jsii 011 the host sea' urchiu,Salmacis vlYIUlalaorul side, show'ng the damage to the bases of the spi'nes. b-Zebrid,Q adamsii dorsal view of female. c-First mal~ pleopod, abdominal view. 114 Bu ltetln (J:r~he Zoological Survey o/India

and South Pacific lsland. (Clarke and Rowe causing damages to the spines and tube feet 1971). of the sea urchins so as to elucidate the true relationship of the associates. Further the Present records life-history of this crab has to be worked out in detail since this is not known. These two The parthenopid crab, Z. adamsii is investigations are now in progress at this recorded for the first time from the Bay of laboratory. Bengal. No record has been made of this crab in association with sea urchin from the ACKNOWLBDGEMENTS Bay of Bengal. In the presept study the animal associates (crab and echinoid) have The authors are grateful to· Dr. T. N. been collected from 18-20 metres. Ananthakrishnan, Director, Zoological Survey of India, Calcutta for encouragement faci­ REMARKS lities given to undertake this work and for helpful suggestions in the preparation of this The occurrence of the parthenopid crab, paper. One of us (S. Krishnan) is thankfuL Z. adamsii has been recorded earlier on other to the CSIR, New Delhi ·for the aW81'i of species of sea urchins like Toxopneusles the Pool Placement to work in the Marine pilfJos!Js a"nd Sa/macis hicolor Rathbun (1910), Biological Station of the Zoological Survey AnthocidQris crossipina (Udta, 1926), Aean­ of India, Madras. thocidaris sp. (Blass, 1956), Asthenosoma ijimai (Doki. 1972), REFERENCES (Yamamoto, 1973, and Suzuki and Takeda, 1974). Yamamoto (1973) observed that Z. AGASSIZ, L. 1846. In : Agassiz, L., & De'S or, B. 184:6. Catalogue raisonne" des families, des geners et des adams;i cha.nged the ho st from T. gratilla to "espec'es de la c1asse des Echinoderms. A nnllis. Sci. in the aquarium. This view nat., (3) 6: 325-374. has been contradicted by Suzuki and Takeda ·B~ASS, H. 1956. Decapoda, VI. Okologie In. Dr. H. G. (1974). In our observations on S. virgulata Bronns Klassen und ordungen des Tie"eichs, 8 : 1285- and the associate in the aquarium tank for 1504. more than two weeks, changing from one Clark, A. M., and F. W. E. Rowe. 1971, Monograph of host to another, even among the same species shallow-water Indo-West Pacific Echinoderms. pp." 210. Trustees of the British Museum, London. was not observed. DOKI, R. 1972. (Zeb,ida aaamsii attached to· a sea urchin (Asthenosoma ijimai)~ Nankiseibutu, 14 : 25 Mortenson (1904) considered Z. ada -nsii (In Japanese). causing damage to the tube feet of the host LESKE, N. G. 1778. Additawenta ad Jacobi Theodoti echinoid, as due to parasitism. Suzuki and Klein Naturalem Dispositionem Echinodermatum et Takeda (1974) decidedly concluded that this Lucubratiunculum de Aculeis ;Echinorum. Lipsiae: XX-1-214, pIs. 37-53. crab which is not a commensal of sea urchins was without doubt a parasitic species inflict­ MORTENSON, T. 1904. The Danish Expedit~on to Siam 1899-1900. II Echinoidea (I). D.K. Danske 'Vide S6lsk. ing minor damages to the hosts. From our Sk1'., (7J, 1 : 1-124 pIs. 1-7. present observations it is concluded that the spines of the sea urchins get weakened du~ RATHBUN, M. J. 1910. The Danish Expedition to Siam 1899-1900. V. Brachyura, D. K. Danske Vitl to the movement of the crab resulting in the Selsk, Sky., (7) 4 : 303-367. minor damages to the spines at base. It is highly desirable to make further studies on SERENE, R. 1968. The Bradiyura.... , of the "Indo-West Pacific region. pp. 33-112 lctclostyled report), the exact role played by Z. adamsii White in Singapore. DANIBL & KRISHNAN : On Porlhenopld crab 175

Su mIa, X., and M. TAXItDA., 1974. On a parthenopid Wan'B, A. 1847. Descriptions of new crustacea of the crab, ~.britl. adtunsii on the sea urchins from. Surugn ~nstern seas. P,oc. Zoo,. Soc. Lona., 1847: 56-58, Day, ..ith a special referel1ce to their parasitic 84~87, 118-125. relations. B,,,,. fI(lln. Sci, Mus. Tokyo. 17 (4) : 187·196. YAMAMOTO, '1'. 1979. (A small aud beautiful crab, Z ebrida adamsii White in the Bay of SUKumo-wan.) trdA.. T. 1926, (list of crabs from Kagosbitna Asahi-Larollsse Shukau Sekai Dobutsu Hyakka 130: prefeetura) Zool. Mag., 30: 160-164, 192-196 (In 30 (In Japanese). Japanese),