Miscel.lania Zoologica 21.1 (1998) 37

Morphology of the megalopa and first crab instar of the Shamef aced Crab Calappa granulata (Crustacea, Brachyura, Calappidae)

G. Guerao, P. Abelló & J. Cartes

Guerao, G., Abelló, P. & Cartes, J., 1998. Morphology of the megalopa and first crab instar of the Shamefaced Crab Calappa granulata (Crustacea, Brachyura, Calappidae). Misc. Zool., 21.1 : 37-47.

Morphology of the rnegalopa and first crab instar of the Shamefaced Crab Calappa granulata (Crustacea, Brachyura, Calappidae).-An unknown large megalopa was captured alive in a plankton sample taken south of Eivissa (Balearic Islands) in the western Mediterranean. The juvenile was obtained after moulting of the megalopa in the laboratory. The morphology of the first crab stage allowed the identification of the megalopa as belonging to the species Calappa granulata. Heterochely with right handedness is already evident in the megalopa stage. Its morphological characters are compared with those of the other known megalopae of related species.

Key words: Megalopa, Calappa, Calappidae, Heterochely.

(Rebut: 9 XII 97; Acceptació condicional: 2 1 IV 98; Acc. definitiva: 19 V 98)

Guillermo Guerao, Dept. de Biologia Animal, Fac. de Biologia, Uni~de Barcelona, AK Diagonal 645, 08028 Barcelona, Espanya (Spain).- Pere Abelló & Joan Cartes, lnstitut de Ciencies del Mar (CSIC), Passeig Joan de Borbó sln., 08039 Barcelona, Espanya (Spain).

O 1998 Museu de Zoologia 38 Guerao et al. lntroduction at a constant room temperature of 17t1°C in aquaria with filtered well-aerated sea Two species of the family Calappidae are water. The first crab stage was obtained by known to inhabit the western Mediterra- rearing this megalopa in the laboratory. The nean waters (GARC~A-RASO,1993; SERIDJI, 1993; exuvia of the megalopa and the juvenile STEVCIC & GALIL, 1994): Calappa granulata crab (which died after 11 days in the labo- (Linnaeus, 1758) and Cryptosoma cristatum ratory) were preserved in 70% ethanol. The Brullé, 1837 [cited as Cycloes cristata: GARC~A-first crab stage is deposited in the Biologi- RASO (1993)]. cal Collections of Reference of the lnstitut Calappa granulata is a sublittoral species de Ciencies del Mar (CSIC) in Barcelona (Reg- known from the Mediterranean Sea and istration number: ICMD 29911997). eastern Atlantic waters from Portugal to An Olympus phase contrast microscope Mauritania, including the Azores, Madeira, was used in the observation, after mount- and the Cape Verde lslands (ZARIQUIEY.-ing the features of the appendages in poly- ÁLVAREZ,1968; MANNING& HOLTHUIS,1981). It vinyl lactophenol. Dissection and measure- lives on sandy mud and muddy detritus at ments were taken with a Wild binocular depths of between 13 and 400-700 m (MAN- microscope equipped with an ocular mi- NING & HOLTHUIS,1981). crometer. All drawings were made with the The morphology of the larval stages of aid of a camera lucida. Carapace width calappid crabs is insufficiently known (RICE, was measured as the greatest distance 1980; STEVCIC, 1983). There are only a few across the carapace, and carapace length papers concerning the larval development as the distance between the frontal mar- of calappid crabs and most of them deaA gin and the posterior margin of the cara- only with the zoeal or prezoeal stages pace. The megalopa is described using the (LEBOUR,1944, 1959; RAJA BAI, 1959; MOTOH, basic malacostracan somite plan from ante- 1977; SERIDJI, 1993; GONZÁLEZ-GORDILLO,1994; rior to posterior and appendage segments TAISHAKU& KONISHI,1995). The megalopal are described from proximal to distal, stage is known only for Calappa flammea endopod then exopod. The morphological and Cryptosoma bairdii [cited as Cycloes description of the first crab is restricted to bairdii: GALIL& CLARK(1 996)], based on two the most definitive characters, and to the incomplete descriptions made by LEBOUR main differences from the adult form. The (1944) of specimens collected from the number of setae present in each segment plankton off Bermuda. Concerning C. of the appendages is that stated in the granulata, only the prezoeal stage is di- text; some setae present in the concealed rectly known from an ovigerous female face of the appendages are not figured in (GONZÁLEZ-GORDILLO,1994), whereas the first the drawings. zoeal stage appears to be known from a plankton sample (SERIDJI,1993). The present paper describes the morphol- Results ogy of the megalopa and the first juvenile crab of Calappa granulata. It constitutes the Megalopa first complete description of a megalopa of the family Calappidae. Dimensions Carapace length: 4.6 mm; carapace width: 3.7 mm. Material and methods Carapace (figs. 1A-C) An unknown large megalopa was collected Longer than broad and without spines; dor- alive in a plankton sample taken 50 km sal surface smooth; frontal region and ros- southeast of Formentera (38O12.6 N, 1°42.3 E; trum gradually deflected ventrally. Balearic Islands; western Mediterranean) on 27 X 96 during the cruise "QUIMERA 1". The Antennule (fig. 2A) megalopa was kept in a storage tank at Peduncle three-segmented, with 13,4,4 se- 17°C. transported to the laboratory and kept tae, basal segment bulbous; endopod Miscel.lania Zoologica 21.1 (1998) 39

Fig. 1. Calappa granulata, megalopa: A. Lateral view; B. Rostrum, frontal view; C. Dorsal view; D. Sternum. (Scale bars: A-C, 1 mm; D, 0.7 mm.) Calappa granulata, mega1opa:A. Vista lateral; B. Rostro, vista frontal; C. Vista dorsal; D. Sternum. (Escalas: A-C, 1 mm; 0, 0,7 mm.) 40 Guerao et al.

unsegmented with five setae; exopod four- developed tubercle, placed near the base, segmented with 0,15,11,7 aesthetascs and and directed posteriorly; teeth of the right 0,0,2,2 setae, respectively. propodus more developed than those in the left. Dactyli of second to fifth pereiopods Antenna (figs. 2B, 2C) long, with 8,8,7,3 small spines on the inner Protopod three-segmented, with 6,4,1 se- margin; dactyl of fifth pereiopod with three tae; flagellum eight-segmented, with long subterminal setae. 0,0,4,2,4,2,3,4 setae. Sternum (fig. 1D) Maxillule (fig. 20) Sternite of second and third pereiopods with Coxal endite with 21 setae; basial endite a pair of rounded tubercles. with 27 setae, and four setae on its inner lateral margin; endopod unsegmented with Abdomen (figs. IA, 1C) three setae. With six somites, broader than longer, with well-developed tergites, plus telson; postero- Maxilla (figs. 2E, 2F) lateral margins of second to fifth segments Coxal endite deeply bilobed with 17+7 se- rounded; setal arrangement as figured. tae; basial endite bilobed with 9+13 se- tae; endopod unsegmented with seven Pleopods (fig. 4G-1) setae in its outer lateral margin; exopod Biramous; present on second to sixth abdomi- (scaphognathite) with 126 marginal setae nal segments; endopod of second to fifth and 12 medial setae. pleopods unsegmented with 6,5,4,5 sub- terminal coupling hool

Fig. 2. Calappa granulata, megalopa: A. Antennule; B. Antenna; C. Antenna, segments 5-8; D. Maxillule; E. Maxilla, scaphognathite; F. Maxilla, endopod, basis and coxa. (Scale bars: A, B. E, 0.2 mm; C, D, F, 0.1 mm.) Calappa granulata, megalopa: A. Anténula; B. Antena; C. Antena, segmentos 5-8; D. Maxílula; E. Maxila, escafognatito; E Maxila, endopodio, basis y coxa. (Escalas: A, B, E, 0,2 mm; C, D, F; O, 1 mm.) 42 Guerao et al.

Fig. 3. Calappa granulata, megalopa: A. First maxilliped; B. Second maxilliped; C. Third maxilliped. (Scale bars: 0.2 mm.) Calappa granulata, megalopa: A. Primer maxilípedo; B. Segundo maxilípedo; C. Tercer maxilípedo. (Escalas: 0,2 mm.) Miscel.lania Zoologica 21.1 (1998) 43

Fig. 4. Calappa granulata, megalopa: A. Right cheliped; B. Left cheliped; C. Second pereiopod; D. Third pereiopod, dactyl; E. Fourth pereiopod, dactyl; F. Fifth pereiopod; G. First pleopod; H. Fourth pleopod; l. Telson and right uropod, ventral view (setules of the setae omitted). (Scale bars: A, B. 1 mm; C-F, 0.4 mm; G-l. 0.2 mm.) Calappa granulata, megalopa: A. Quelípedo derecho; B. Quelípedo izquierdo; C. Segundo pereiópodo; D. Tercer pereiópodo, dáctilo; E. Cuarto pereiópodo, dáctilo; F: Quinto pereiópodo; G. Primer pleópodo; H. Cuarto pleópodo; l. Telson y urópodo derecho, vista ventral (sétulas de las sedas, omitidas). (Escalas: A, B, 1 mm; C-6 0,4 mm; G-1, 0,2 mm.) Guerao et al. on the right); propod very high, strongly the chelipeds are very similar to those of C. widening anteriorly, almost as long as high, granulata described herein. The size of the with a dorsal dented keel; right propod with carapace is also large and similar (4.2 mm in a large blunt tubercle; dactyl directed C. flammea vs. 4.6 mm in C. granulata). The ventrally; dactyl of the right chela wider than only setation counts given by LEBOUR(1944) the left and with a large blunt tubercle near on C. flammea are those of the uropods its base; dactyl of the left chela much thin- (20 setae), almost coinciding with the 20-21 ner and without a developed tubercle. given in the present description for C. granulata. Pereiopods The megalopa of Hepatus epheliticus and Thin, without spines or tubercles, similar to H. pudibundus (COSTLOW& BOOKHOUT, 1962; the adult; dactyl long. RIEGER& HEBLING,1993) differs widely from that of Calappa granulata in many aspects: the C. granulata is much larger (4.6 mm vs Discussion approx. 1.3 mm in H. epheliticus and H. pudibundus); the shape of the rostrum and Knowledge of the larval development and frontal region are very different; the shape morphology of calappoid crabs is limited. and relative size of the chelae are elon- The taxonomic position of the family gated and flattened dorso-ventrally, as in Calappidae was recently reviewed by the adult crab, in C. granulata, while the BELLWOOD(1996) who showed that this fam- chelae of H. epheliticus and H. pudibundus ily is not monophyletic and that the crab are not so calappid-like; the setation of the species of this group may now be arranged appendages is more developed in C. as belonging to three different families: granulata. Calappidae and Hepatidae within the An interesting feature presented by the superfamily Calappoidea, and Matutidae, megalopa of Calappa granulata and, to our which together with Leucosiidae would form knowledge, not previously reported for any the superfamily Leucosioidea. SERIDJI (1993) other brachyuran megalopa, is that right- studied the affinities between the genera handed heterochely is already present at of Calappidae at the larval level and al- this stage. ready envisaged the conclusions reported The megalopa of Calappa granulata can by BELLWOOD(1996) based on adult crabs. be easily distinguished from other crab SERIDJI (1993) reported that the zoeae of megalopae known from Mediterranean and Hepatus are closely related to those of north-eastern Atlantic waters by its large Calappa, while those of Matuta are clearly size, large and characteristic chelipeds, and distinct. Therefore, the complete larval de- the high number of setae on the scaphog- velopment within the family Calappidae nathite. (sensu stricto) is unknown for any species, The morphology of the first crab ob- since that of Hepatus epheliticus described tained in the present study agrees with that by COSTLOW& BOOKHOUT(1962), and H. of the adult Calappa granulata, especially pudibundus described by RIEGER& HEBLING in the characteristic and diagnostic features (1993) would correspond to the family of the species (overall shape, placement of Hepatidae. spines, etc.) (ZARIQUIEY-ÁLVAREZ,1968), and Within the family Calappidae, the differs from that figured by MANNING& megalopal stage is known only for Calappa HOLTHUIS(1981) for other eastern Atlantic flammea and Cryptosoma bairdii from in- Calappa juveniles. The ratios of the inter- complete descriptions given by LEBOUR(1944). ocular length versus carapace width, as well No information on setation is provided and as the ratio of carapace length versus cara- their morphological characteristics are not pace width, are larger than in adult crabs, given in detail. No appendages are de- showing the occurrence of a strong nega- scribed and the only drawings presented tive allometry in the growth of these meas- show the overall dorsal morphology of the urements throughout ontogeny. PASTORE whole animal. Concerning the megalopa of (1995) recently described two new species C. flammea, the overall carapace shape and of the genus Calappa in the lonian Sea Miscel.lania Zoologica 21.1 (1998) 45

Fig. 5. Calappa granulata, first crab: A. Caparace, dorsal view; B. Abdomen, dorsal view; C. Right cheliped; D. Left cheliped. (Scale bars: A-D, 1 mm.) Calappa granu lata, juvenil: A. Caparazón, vista dorsal; B. Abdomen, vista dorsal; C. Quelípedo derecho; D. Quelípedo izquierdo. (Escalas: A-D, 1 mm.)

(eastern Mediterranean basin), mainly based Acknowledgements on colour differences and widely overlap- ping meristic characteristics. The morphol- We are very grateful to al1 participants in ogy of the juvenile crab examined does not the cruise "QUIMERA 1" (FAIR-CT95-0655) suggest that it could be assigned to either on board RIV "García del Cid", and espe- of these species. cially to Drs. J. B. Company and D. Lloris. 46 Guerao et al.

Thanks are also dueto Drs. J. l. González- of the status of the family. Zool. J. Linn. Gordillo and J. A. Cuesta for their valuable SOC., 118: 165-193. help in locating al1 necessary references COSTLOW,J. D. & BOOKHOUT,C. C., 1962. The and for their encouragement towards the larval development of Hepatus epheliticus study of larval crustaceans. (L.) under laboratory conditions. J. Elisha Mitchell Sci. Soc., 78: 11 3-1 25. GALIL,B. & P. F. CLARK.,1996. A revision of Resumen Cryptosoma Brullé, 1837 and Cycloes de Haan, 1837 (Crustacea: Brachyura: Calap- Morfología de la megalopa y del primer pidae). Zool. J. Linnean Soc., 117: 175-204. estadio juvenil del cangrejo real Calappa GARC~A-RASO,J. E., 1993. New record of granulata (Crustacea, Brachyura, Calappidae) other African species of Crustacea Decapoda, Cycloes cristata (Brulle), from Una megalopa de gran tamaño, de morfolo- European and Mediterranean waters. Bios gía no descrita, fue capturada viva en una (Thessaloniki), 1: 21 5-221. muestra de plancton tomada al sur de Eivissa GONZÁLEZ-GORDILLO,J. l., 1994. Descripción de (islas Baleares) en el Mediterráneo occiden- los estadios de prezoea en Cycloes cristata tal. Un juvenil se obtuvo por muda de la (Brulle, 1837) y Calappa granulata megalopa en el laboratorio. La megalopa es (Linnaeus, 1758) (Decapoda, Brachyura, de gran tamaño (4,6 mm de longitud de Calappidae). Bol. Inst. Esp. Oceanogr., 10 cefalotórax), más larga que ancha y sin espi- (1): 33-39. nas; el rostro se inclina gradualmente en LEBOUR,M. V., 1944. Larval crabs from Ber- dirección ventral (fig. 1). Se describe el nú- muda. Zoologica, 29: 113-128. mero y posición de las sedas de los distintos - 1959. The larval decapod crustacea of apéndices (figs. 2-4). El número de sedas del tropical west Africa. Atlantide Rep., 5: escafognatito es alto. Los quelípedos son 119-143. grandes y comprimidos, con el dáctilo dirigi- MANNING,R. B. & HOLTHUIS,L. B., 1981. West do ventralmente. Heteroquelia diestra (pin- African brachyuran crabs (Crustacea: za derecha con morfología robusta) es evi- Decapoda). Smithsonian Contr. Zool., 306: dente en el estadio megalopa (fig. 4). 1-379. Los caracteres mrofológicos de la mega- MOTOH,H., 1977. Note: larvae of decapod lopa se comparan con los de otras megalopas crustacea of the Philippines. II. Labora- conocidas de especies cercanas (superfamilia tory-hatched first zoea of box crab. Phil- Calappoidea). La morfología del primer esta- ippine Agriculturist, 60: 345-350. dio de cangrejo permitió identificar la PASTORE,M., 1995. The genus Calappa in the megalopa como perteneciente a la especie lonian Sea. Oebalia, 21: 187-196. Calappa granulata. El cefalotórax (fig. 5) es RAJA BAI, K. G., 1959. Studies on the larval ligeramente más largo que ancho, fuerte- development of Brachyura III - Develop- mente convexo; la región frontal es más an- ment of Calappa lophos (Herbst) and cha que en el adulto; el rostro es bilobado y Matuta lunaris (Forskal) (Crustacea: protrude ligeramente; los márgenes antero- Brachyura). J. Zool. Soc. India, 11: 65-72. laterales son redondeados, presenta cuatro RICE, A. L., 1980. Crab zoeal morphology and dientes postero-laterales y cuatro dientes its bearing on the classification of the posteriores, como el adulto; el margen me- Brachyura. Trans. Zool. Soc. London, 35: dio posterior es recto. Este estudio constitu- 27 1-424. ye la primera descripción completa de una RIEGER, P. J. & HEBLING,N. J., 1993. Desenvolvi- megalopa de la família Calappidae. miento larval de Hepatus pudibundus (Herbst, 1785) (Decapoda, Calappidae), em laboratório. Rev. Brasil. Biol., 53(4): 51 3-528. References SERIDJI, R., 1993. Descriptions of some plank- tonic larvae of the Calappidae (Crustacea: BELLWOOD,O., 1996. A phylogenetic study of Decapoda: Brachyura). J. Plank. Res., 15: the Calappidae H. Milne Edwards 1837 437-453. (Crustacea: Brachyura) with a reappraisal STEVCIC,Z., 1983. Revision of the Calappidae.