OCCURRENCE OF THE SQUID, LOLLIGUNCULA BREVIS, IN SOME COASTAL WATERS OF WESTERN FLORIDN ALEXANDER DRAGOVICH Tropical Atlantic Biological Laboratory, Bureau of Commercial Fisheries, lVfiami AND JOHN A. KELLY, JR. Biological Laboratory, Bureau of Commercial Fisheries, St. Petersburg Beach, Florida

ABSTRACT Lolliguncula brevis (Blainville) is the dominant cephalopod in the Tampa Bay and Charlotte Harbor-Pine Island Sound areas of west Florida. Distribution and seasonal occurrence of the species are discussed. The temperature and salinity ranges at which squid occurred were 12.6 to 31.6°C and 18.19 to 36.15%c. The majority of the squid collected were immature.

This note presents information on the occurrence and distribution of squid in bays of the central west coast of Florida and adjacent neritic waters of the Gulf of Mexico. Published material pertaining to the systemat- ics and geographical distribution of cephalopods in the Gulf of Mexico is limited to the work of Voss (1950, 1954, 1955, 1956a, 1956b). Little is known about the distribution of squid in Florida estuaries and adjoining marine waters (Tabb & Manning, 1961; Dragovich & Kelly, 1963). In Florida, squid is used extensively as bait by commercial and sport fisher- men (Dragovich & Kelly, 1963), and small amounts are consumed by humans. Samples were collected from September, 1962, through December, 1962, with a ten-foot, shrimp try-net, and from January, 1963, through Decem- ber, 1964, with a 16-foot, semi-balloon trawl. Both nets had one-inch, stretch mesh. Most of the stations in Tampa Bay and the adjacent oceanic waters were sampled semimonthly during 1962, monthly during 1963, and in alternate months during 1964. Six stations in Charlotte Harbor and three in Pine Island Sound were sampled monthly only, during 1964. Water temperatures at each station were recorded with a Whitney under- water thermometer (Model T 65), or with a mercury thermometer graduated to 0.1 0c. Salinity was determined by the Mohr-Knudsen method (Knudsen, 1901). Of 648 squids collected, all except one were Lolliguncula brevis (Blain- ville), the brief squid. The single specimen was an immature Doryteuthis

1Contribution No. 62, Tropical Atlantic Biological Laboratory, Bureau of Commercial Fisheries, Miami, Fla. 1967J Dragovich & Kelly: Occurrence of Lolliguncula brevis 841

28" 00

SQUID: • Present

, J Absent

MEXICO

o 0

27 30'

SQUID: • Present o Absent

26" 30'

-L 82"30' 82"00'

FIGURE 1. Distribution of Lolliguncula brevis at the stations sampled in Tampa Bay, Charlotte Harbor, and Pine Island Sound, and the adjacent offshore waters of the Gulf of Mexico, September, 1962, to December, 1964. 842 Bulletin of Marine Science [17(4)

TABLE 1 NUMBERS OF Lolliguncula brevis COLLECTED IN TAMPA BAY, CHARLOTTE HARBOR, AND PINE ISLAND SOUND, FLORIDA, IN DIFFERENT MONTHS Year and location Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 1963 Tampa Bay 17 14 22 8 0 27 0 0 12 13 18 0 (13 stations) (8)* (12) (12) (12) (12) (12) (12) (12) (12) (12) (5) (J I) 1964 Charlotte Har- bor and Pine 7 0 0 0 1 2 0 0 10 J9 27 0 Island Sound (9) (4) (6) (6) (6) (6) (6) (6) (6) (6) (6) (6) (6 stations) • The number of lO-minute trawl hauls made each month is shown in parentheses. plei (Blainville), 116 mm Jong, collected in December, 1963, at the mouth of Tampa Bay; it is not included in the account that follows. Sex and maturity were determined for all except a few immature speci- mens on the basis of the size-maturity relationship reported for this species by Dragovich & Kelly (1963). The dorsal mantle length (tip of the anterior lobe to the posterior end of the mantle) was measured with vernier calipers. L. brevis is the dominant cephalopod in the Tampa Bay and Charlotte Harbor-Pine Island Sound areas. Previously, the species was reported on the west coast of Florida only from Tampa Bay (Dragovich & Kelly, ] 963) and near Cape Sable, 160 miles south of Tampa Bay (Tabb & Manning, 196]). Charlotte Harbor and Pine Island Sound are two major embayments between these points. It is evident, therefore, that the species inhabits almost all the waters along the southwestern coast of Florida. Squid were collected at 22 of the 40 stations sampled: at ]6 of 29 stations in Tampa Bay (but not at 2 offshore stations), and at 6 of 9 stations in Charlotte Harbor and Pine Island Sound (Fig. I). Squid were collected in Tampa Bay in all months of 1963 except May, July, August, and December (Table 1); in Charlotte Harbor and Pine Island Sound, they were most abundant during September, October, and November, and were absent or scarce in the remaining months. Both mature and immature squid were collected in each month except July (when no squid were captured). In a previous study also, mature squid were absent from the trawls during July (Dragovich & Kelly, 1963). Immature squid dominated at most of the sampling locations; 75 per cent of all squid captured were immature. Of the mature specimens, 5] per cent were male and 49 per cent female; of the immature, 89 per cent were male and 11 per cent female. 1967] Dragovich & Kelly: Occurrence of Lolliguncula brevis 843 The temperature at which squid occurred ranged from 12.6 to 31.6°C, and the salinity from 18.19 to 31.151". This salinity range agrees with that reported by Dragovich & Kelly (1964), Gunter (1950), Tabb & Manning (1961), and Haefner (1959). L. brevis is one of the few cephalopods which can tolerate estuarine salinities. The distribution of squid was not uniform (Fig. 1). In Tampa Bay, they were present in areas with soft bottoms consisting primarily of mud, clay, or silt. At most of the stations where they were absent, the bottom was covered with coarse sand and grass. At stations in Pine Island Sound and Charlotte Harbor, squid were about equally distributed over both sandy and clay (or soft) bottoms. The survey indicated that squid inhabit shallow coastal waters of western Florida with salinities lower than those in the adjacent waters of the Gulf of Mexico. On the basis of this and previous studies (Tabb & Manning, 1961; Dragovich & Kelly, 1963), L. brevis may be considered a euryhaline species and an important component of the resident, estuarine biota of western Florida.

ACKNOWLEDGMENTS We thank Dr. G. L. Voss and Mr. Clyde F. E. Roper, of the Institute of Marine Sciences, University of Miami, for their helpful suggestions during the study and for critically reading the manuscript. Mr. John H. Finucane, Biological Laboratory, S1. Petersburg Beach, Florida, collected the specimens for this study.

SUMARJO PRESENCIA DEL CALAMAR Lolliguncula brevis EN ALGUNAS AGUAS COSTERAS DE LA REGION OCCIDENTAL DE LA FLORIDA Lolliguncula brevis (Blainville) es el cefal6podo predominante en Tampa Bay y Charlotte Harbor. Se discuten la distribuci6n y ocurrencia estacional de la especie. Los valores de la temperatura y la salinidad de los lugares donde se encontr6 el calamar fueron de 12.6 a 31.6°C y de 18.19 a 36.151", respectivamente. La mayoria de los ejemplares colectados no estaban sexualmente maduros. La especie se encuentra en casi todas las aguas a 10 largo de la costa sudoeste de la Florida. Basandose en esto y en estudios previos, L. brevis puede ser considerada una especie euri- hialina y un componente importante de la biota estuarina del oeste de la Florida. LITERATURE CITED

DRAGOVICH, ALEXANDER AND JOHN A. KELLY, JR. 1963. A biological study and some economic aspects of squid in Tampa Bay, Florida. Proc. Gulf Carib. Fish. Ins!., Fifteenth Ann. Sess. Pp. 87-102. 844 Bulletin of Marine Science [17(4)

GUNTER, G. 1950. Seasonal population changes and distribution as related to salinity, of certain invertebrates of the Texas coast, including the commercial shrimp. PubIs. Inst. Mar. Sci., 1 (2): 7-51. HAEFNER, P. A., JR. 1959. Morphometry and biology of Loligo pealei Lesueur, 1821 and Lolliguncula brevis (Blainville, 1823) in Delaware Bay. M.S. Thesis, Univ. of Delaware. 61 pp. KNUDSEN, M. 1901. Hydrographical tables. G. E. C. Gad, Copenhagen. 63 pp. TAnn, D. C. AND R. B. MANNING 1961. A checklist of the flora and fauna of northern Florida Bay and adjacent brackish waters of the Florida mainland collected during the period July 1957 through September 1960. Bull. Mar. Sci. Gulf & Carib., 11 (4): 552-649. Voss, G. L. 1950. Two new species of cephalopods from the Florida Keys. Revista Soc. malac. Carlos de la Torre, 7 (2): 73-79. 1954. Cephalopoda of the Gulf of Mexico, Fish and Wildl. Serv., Fish. Bull., 55: 475-478. 1955. The cephalopoda obtained by the Harvard-Havana expedition off the coast of Cuba in 1938-39. Bull. Mar. Sci. Gulf & Carib., 5 (2): 81-115. 1956a. A checklist of the cephalopods of Florida. Quart. J. Fla. Acad. Sci., 19 (4): 274-282. 1956b. A review of the cephalopods of the Gulf of Mexico. Bull. Mar. Sci. Gulf & Carib., 6 (2): 85-178.