Old Dominion University ODU Digital Commons OEAS Faculty Publications Ocean, Earth & Atmospheric Sciences 1979 Development of Pelagic Larvae and Postlarva of Squilla empusa (Crustacea, Stomatopoda), with an Assessment of Larval Characters within the Squillidae Steven G. Morgan Old Dominion University Anthony J. Provenzano Jr. Old Dominion University Follow this and additional works at: https://digitalcommons.odu.edu/oeas_fac_pubs Part of the Aquaculture and Fisheries Commons, and the Biology Commons Repository Citation Morgan, Steven G. and Provenzano, Anthony J. Jr., "Development of Pelagic Larvae and Postlarva of Squilla empusa (Crustacea, Stomatopoda), with an Assessment of Larval Characters within the Squillidae" (1979). OEAS Faculty Publications. 191. https://digitalcommons.odu.edu/oeas_fac_pubs/191 Original Publication Citation Morgan, S. G., & Provenzano, A. J. (1979). Development of pelagic larvae and postlarva of Squilla empusa (crustacea, stomapoda), with an assessment of larval characters within the squillidae. Fishery Bulletin, 77(1), 61-90. This Article is brought to you for free and open access by the Ocean, Earth & Atmospheric Sciences at ODU Digital Commons. It has been accepted for inclusion in OEAS Faculty Publications by an authorized administrator of ODU Digital Commons. For more information, please contact [email protected]. DEVELOPMENT OF PELAGIC LARVAE AND POSTLARVA OF SQUILLA EMPUSA (CRUSTACEA, STOMATOPODA), WITH AN ASSESSMENT OF LARVAL CHARACTERS WITHIN THE SQUILLIDAE STEVI':N G. MOH(;AN' AND ANTHONY J. PH()VI':NZ,\NO, JH." ABSTRACT Larvae of the predatory crustacean Squilla empusa were collected from the plankton in Chesapeake Bay and reared in the laboratory topermit description ofthe pelagic stages before the postlarval stage. Characters such as rostral length and spinulation, carapace spinulation, relative size of telson, overall body size, and appearance probably areofmore value for specific than for generic identification. The presence or absence ofteeth on the dactylus ofthe second maxilliped, the presence or absence of a spine on the basis of the second maxilliped, and the number of epipods may be useful characters in determining generic alliances oflarvae belonging to the Squillidae, but present data are not adequate for construction of generic keys to stomatopod larvae Mantis shrimps are formidable predators, able to served that it is the most abundant crustacean in slice a swimming shrimp in half or smash open a the offshortt trawl fishery of the Gulf of Mexico bivalve with enlarged second maxillipeds (Mac­ except for Penaeus sp. and Callinectes sp. Ginitie and MacGinitie 1965). Even though the Stomatopods are fished and eaten in most strike occurs under water, it is one of the fastest Mediterranean countries, Japan, and the tropical movements known in the animal kingdom taking Pacific (Kaestner 1970). 4 to S ms to complete and traveling at a velocity of Like the adult, the larvae of S. empusa are 1,000 cm/s (Burrows 1969), Basically, any animal rapacious predators. Able to attain a length of 17 of appropriate size may fall prey to a stomatopod mm, they can capture zooplankters as large as including fish, shrimp, crabs, annelids, clams, themselves by using their second maxillipeds mussels, snails, squids, and echinoderms (Pic­ (Lebour 1924). Squilia empusa larvae not only fill cinetti and Manfrin 1970). a role as predators, but also as prpy. To date very Stomatopod larvae are often met with in great little has been published on the ecology of the swarms, particularly in tropical waters. The larvae nor has the sequence ofpelagic stages been planktonic larval stages constitute a considerable established for this species. portion of the diet of reef fishes and commercially Ofthe 350 known species ofstomatopods, only 1 important pelagic fishes such as the tunas, skip­ in 10 can be identified with their larvae and only 1 jack tuna, mackerel, herring, and snapper (Sunier has been reared from hatching to metamorphosis. 1917; Fish 1925; Reintjes and King 1953; Randall Difficulty in rearing the larvae has forced inves­ 1967; Dragovich 1970). tigators to base their accounts on reconstructions Squilla empusa Say ISIS is found in the western made from preserved specimens or from holding Atlantic Ocean and ranges from Massachusetts, planktonic larvae through one ecdysis to connect U.S.A. to northern South America, including successive stages. The species of stomatopods for Trinidad, Venezuela, Surinam, and French which larvae are definitely known by the rearing Guiana (Manning 1969). It is abundant through­ of late stage larvae through metamorphosis were out its range, but is especially prevalent in com­ listed by Provenzano and Manning (197S). mercial shrimp beds, and is believed to be a serious Stomatopod species for which larvae are definitely predator of the shrimp. Hildebrand (1954) ob- known by the hatching of eggs also are listed by Provenzano and Manning. 'Institute of Oceanography, Old Dominion University, Nor­ The only description of the developmental se­ folk, Va.; present address: Institute of Marine Science, Univer­ quence ofS. empusa was made almost 100 yr ago sity of North Carolina, Morehead City, NC 28557. "Institute of Oceanography, Old Dominion University, Nor· by Brooks (IS7S) who captured larvae at Fort Wool folk, VA 23508. near the mouth of the Chesapeake Bay. Because Manuscript alTl·ptl·d August 1H7H. 61 FISHEI,Y BULLETIN: VOL. 77. NO. I, lfl7n. FISHERY BULLETIN: VOL. 77. NO. I none of Brooks' larvae metamorphosed into post­ stepped oblique tows, as the ship circled the collec­ larvae, he could not be sure oftheir identity. How­ tion site at idle speed. ever, ofthe thousands he collected, all appeared to Each plankton sample was placed into one or Brooks to be "specifically identical" and the series two 1.9-1 (%-gal) jars filled with seawater until of forms were so complete with the differences stomatopod larvae could be separated from the between the successive stages so slight that he sample. Separation oflarvaefrom the samples was concluded there was "no reason to doubt that they started aboard ship and completed in the labora­ are all of the same species, and that species the tory. Larvae were sorted according to size to only one which is known to occur in the minimize cannibalism, and held temporarily in Chesapeake Bay." However, we now know that aerated 1.9-1 jars filled with seawater. early larval stages of at least one other species of The larvae were then placed in compartmen­ stomatopod occur at the mouth ofChesapeake Bay talized plastic trays, one per compartment. Each (Provenzano and Goy, pers. obs.) Brooks' descrip­ tray contained 18 compartments measuring 4.5 x tion is inadequate to permit stages to be 5 x 4 em. Medium for rearing the larvae was made adequately assigned to larvae. from Instant Ocean Synthetic Sea Salts2 (Aqua­ Brooks apparently was unable to obtain success­ rium Systems, Inc., Eastlake, Ohio) and tapwater. ful molting in his larvae, but instead had to rely on Larvae were reared over a range of tempera­ reconstruction to describe the larval history. He tures (10° to 25°C) and salinities (10 to 35%0) in an provided no conjecture as to the number ofpelagic attempt to insure survival of at least some larvae stages, and only partially described four stages. since optimum conditions were unknown. Because Furthermore, the illustrations which Brooks in­ the larvae were not hatched in the laboratory cluded were of whole specimens only; detailed under the temperature-salinity combination at figures of appendages, necessary for accurate which they were reared, some larvae had to be species identification, were not made. acclimated to the test conditions. Lavae were Faxon (1882), working in Rhode Island, held never acclimated to temperature changes of more what he consideredto be the last pelagic stage ofS. than 5°C and lO%oIday. The larvae were main­ empusa until it metamorphosed and could be iden­ tained in total darkness except for briefperiods (15 tified. However, the last stage larva and postlarva to 20 min/day) when they were examined and appear to belong to another species, notS. empusa transferred to newly prepared trays. (see Discussion). Each larva was reared in 25 ml of water and In this paper we describe the pelagic larval de­ given approximately 30Artemia salina nauplii/ml velopment and postlarval stage ofS. empusa. Be­ daily. Decapod larvae and A. salina, grown on cause egg masses were not collected, hatched, and yeast or an algal culture ofDunaliella, were fed to reared, the propelagic stages remain undescribed. larvae that became too large to capture or obtain Furthermore, because larvae were obtained from substantial nutrition from the A. salina nauplii. the plankton, we are not positive that the larvae Larvae were transferred daily, early stages by described as stageI are the true first pelagic stage. means ofa pipette, later stages with a spoon, into However, ofthe hundreds oflarvae collected these compartments containing freshly prepared sea­ stage I larvae are the least developed and closely water and food. During this transfer, frequency of resemble stage I larvae of other species reared molting, duration oflarval development, survival, from eggs. and the stage ofdevelopment were recorded. Dead A brief review of previous efforts to associate larvae were preserved in 70% ethyl alcohol and stomatopod larvae with adults and a discussion of 10% glycerin. Preserved larvae were heated in a possible specific and generic larval characters