FISHERY BULLETIN VOL 77. NO 1 



FlOURE 24. — Squilla empiisa. postlarva. dorsal view. 



( 1946) andS. mu/ilis by Giesbrecht ( 1910), and the 

 remainder have had the last stage described by 

 holding the final pelagic stage until metamor- 

 phosis occurred and the stomatopod could be corre- 

 lated with an adult of the species. Reconstructions 

 of the larval development of three species, .S. man- 

 tis by Giesbrecht ( 1910), O. oratoriu by Komai and 

 Tung (1929), and O. maasavensis by Gohar and 

 Al-Kholy (1957), were attempted by collecting 

 larval stages from the plankton and piecing them 

 together. Metamorphosis from the last larval 

 stage was obtained for O. massavensis, but since 

 the larvae were not reared, the larval histories 

 may not be entirely factual. Thus, because so few 

 larval forms have been identified and because 



most of these have had only one stage described, it 

 is difficult to discover which characters are shared 

 by all members of a genus and which characters 

 are only specific. Of the nine genera of Squillidae 

 which have had larvae described, four genera have 

 had one or more larval stages of a single species 

 described, four more genera have had two species 

 identified, and one genus has had larvae of eight 

 species described. A determination of generic 

 characters is difficult at best for those genera for 

 which only one or two species have been described, 

 especially since there are no adequately rep- 

 resented genera with which to compare charac- 

 ters. 



The third reason why specific characters are of 

 little help in generic definition lies in the incom- 

 plete descriptions of the larval stages. Characters 

 noted by one author are frequently omitted by 

 another, so that even for the genus Oratosquilta, 

 represented by larval descriptions of eight species, 

 consistent characters are difficult to recognize. 



An assessment of larval characters was at- 

 tempted to determine which ones were constant 

 within each genus. Most characters mentioned in 

 the descriptions appeared to vary a gr-eat deal for 

 the species within a genus, or the characters that 

 varied relatively little within a genus were fre- 

 quently found in other species of different genera. 

 Of possible value in defining generic associations 

 is the presence or absence of teeth (other than the 

 terminal ) on the dactylus of the second maxilliped. 

 These teeth occur during the last stage in the 

 genera Anchisquil la , Clorida , Pterygosquilla , and 

 Squilloides, although for each of these genera lar- 

 vae of only one species have been described. The 

 dactylus of P. annata schizodontia is armed with 5 

 to 8 teeth and the first stage is easily diagnosed by 

 the posterior spines of the carapace which bear 6 to 

 16 spirally arranged, proximal spinules. The 

 spinules are replaced by three ventral spinules in 

 the remaining stages (Pyne 1972). The dactyl of 

 the second maxilliped is equipped with two free 

 teeth in A. fasciata, three teeth inS. lata, and inC. 

 latreillei is usually armed with one tooth, rarely 

 with two (Alikunhi 1952). Newly hatched larvae 

 of C. choprai were too inadequately described to be 

 compared withC. latreillei (Tweedie 1935; Gurney 

 19461, but the dactylus of the second maxilliped 

 was observed to be unarmed. This is not surprising 

 since C. latreillei and S. lata develop teeth on the 

 dactylus of the second maxilliped in the later 

 stages and P. armata schizodontia develops its 

 first tooth in the third stage. 



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