CONOR and CONOR: LARVAE OF FOUR PORCELLANIDAE 



this type of growth. Lebour (1943, 1950) was 

 probably the first author to notice specimens 

 showing this phenomenon, Lebour observed 

 some substage molting and concluded that each 

 substage she found in plankton collections must 

 necessarily have been separated from less ad- 

 vanced substages by a discrete molt. She sub- 

 sequently proposed that Pisidia longicornis and 

 Porcellana platycheles probably possessed a var- 

 iable number of stages with two "essential" 

 stages. She assumed that a molt always sep- 

 arated the "alternative" stages, or substages 

 from each other. The variable molting sequence 

 may indeed occur in these species under certain 

 circumstances, as it does in other Anomura 

 (Table 6) , but it is probable that lb and lie sub- 

 stages in Pisidia longicornis and lie in Porcel- 

 lana platycheles, which were taken in plankton 

 samples but never obtained by molt in the lab- 

 oratory, were products of intermolt growth. 



LeRoux (1961, 1966) subsequently reared the 

 larvae of both species and reported only two 

 "true" zoeal stages each of which underwent 

 growth in certain appendage buds without molt- 

 ing. It is likely that these species have the po- 

 tential for both intermolt growth and stage 

 number variability and that Lebour found a com- 

 bination of both while LeRoux did not. A sim- 

 ilar case might also exist in the Petrolisthes lar- 

 vae studied by Wear (1964a, b), although he 

 reports definite ecdysis between each of his sub- 

 stages. Lai^ae of these species, like the Pisidia 

 and Porcellana species mentioned above, may 

 show both intermolt growth and variable stage 

 numbers, depending on environmental circum- 



Table 6. — Species of Anomura other than Porcellanidae 

 for which stage number variability has been reported.' 



Species of Anomura 



Source 



Pleuroncodes planipes 

 Emerita tatpoida 

 Emerita analoga 

 Emerita rathbunae 

 Hippo cubensis 

 Blepharipoda occidentalis 

 Calcinus tibicen 

 Cotnbita clypeatus 

 Triiopagurus magnificus 

 Pftrockirus dioginfS 

 Birgus latro 

 Paralithodfs camtschatica 



Boyd ond Johnson, 1963 



Rees, 1959 



Johnson and Lewis, 1942; Efford, 1970 



Knight, 1967 



Hanson, 1969 



Knight, 1968; Johnson and Lewis, 1942 



Provenzono, 1962a 



Provenzano, 1962b 



Provenzono, 1967 



Provenzano, 1968 



Reese and Kinzie, 1966 



Kurato, 1960 



stances, a possibility not considered for example, 

 by Roberts (1968) and Gore (1970) in discus- 

 sing substages. 



Other authors have subsequently supported 

 Lebour's original substage designation of growth 

 forms even though no molting was observed 

 (e.g., Boschi et al., 1967). This is a needless 

 and confusing subdivision of an apparently con- 

 tinuous process and it obscures the nature of 

 the flexibility of the animals. The term substage 

 is now used in such a variety of ways that it 

 should be abandoned altogether, as (]k)re (1970) 

 has suggested, and attention directed to the pos- 

 sible occurrence of variation in both molting and 

 development rates as observed by Costlow 

 (1965) in the portunid CalUnectes sapidus. 



Intermolt growth to date has been recorded 

 directly or indirectly in the larvae of 70% of the 

 porcellanids studied for which two or more zoeal 

 stages are known (Table 7), All these species 

 have demonstrated abbreviated development 

 (fewer number of molts necessary to attain ju- 

 venile adult form) compared to most other 



Table 7, — Species of Porcellanidae for which intermolt 

 growth or stage number variability have been reported. 

 Includes only species with both zoeae known. 



Species 



Intermolt Stage 

 growth^ variability^ 



Autfior 



Petrolisthts cinctipes + 



Petrolisthes eriomerus + 



Petrolisthes armatus — 



+ 



Petrolisthes elongatus O 

 Petrolisthes novaezelandiae O 



Petrolisthes rujescens O 



Petrolisthes sp. I Q 



Petrolisthes sp. II O 



Porcellana sp. Q 



Porcellana platycheles + 



Porcellana sigsbeiana + 



Pisidia longicornis + 



Pisidia bluteti Q 



Pisidia inaequalis Q 



Polyonyx gibbesi 4" 

 Polyonyx guadriungulatus + 



Pachycheles pubescens -f- 



Pachycheles rudis + 



Pachycheles haigae + 



Pachycheles stevensii + 



Euceramus praelongus + 



Petrocheles spinosus — 



Megalobrachium poeyi + 



— This study 



— This study 



+ Gurney, 1938 



+ Lebour, 1943, 1950 



— Gore, 1970, 1972 

 + Wear, 1964b 



+ Wear; 1964a 



— Gohar and Al-Kholy, 1957 



— Merron, 19G7 



— Menon, 1937 



— Menon, 1937 



— Le Roux, 1961 

 + Lebour, 1943 



— Gore, 1971b 



— Le Roux, 1966 

 + Lebour, 1943 



— Bourdillon-Casanova, 1956 



— Gurney, 1938 



— Gore, 1968 



— Knight, 1966 

 ^ This study 



— Knight, 1966; this study 



— Boschi et al., 1967 



— Kurata, 1964 



— Roberts, 1968 



— Wear, 1965o 



— Gore, 1971a 



^ Intermolt growth has not been reported in the larvae of any of the 

 above species. 



-f- = Occurrence reported. 



— = Occurrence not reported. 



O = Occurrence probable but not directly reported. 



221 



