414 NOAA Technical Report NMFS Circular 414 Synopsis of Biological Data for the Winter Flounder, Pseudo pleuronectes americanus (Walbau m) November 1 978 Is s Technical ircuIar 414 u A1MOsp,, Synopsis of Bioog LW( for the Winter Flounder, i Pseudopleuronectes arnericanus fNTO (Walbaum) Grace Klein-MacPhee November 1 978 FAO Fisheries Synopsis No. 117 U.S. DEPARTMENT OF COMMERCE Juanita M. Kreps, Secretary National Oceanic and Atmospheric Administration Richard A. Frank, Administrator National Marine Fisheries Service ational 1rine Fisheries Service (NMFS) does not approve, rec- oinnend or endorse any proprietary product orproprietary material nntioned in this publication. No reference shall be made to NMFS, or ohis publication furnished by NMFS, in any advertising or saies pro- :uion which would indicate or imply that NMFS approves, recommends o ondorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly Lh advertised product to be used or purchased because of this NMFS ublication. CONTENTS Page i Identity i 1.1 Nomenclature i 1.2 Taxonomy 1.3 Morphology 2 2 Distribution 3 2.1 Total area 3 2.2 Differential distribution 4 2.3 Determinants of distribution 4 2.4 Hybridization 5 3 Bionomics and life history 5 3.1 Reproduction 5 3.2 Preadult phase 6 3.3 Adult phase 9 3.4 Nutrition and growth 12 3.5 Behavior 23 4 Population 25 4.1 Structure 25 4.2 Abundance and density 26 4.3 Natality and recruitment 29 4.4 Mortality and morbidity 30 4.5 Dynamics of the population as a whole 31 4.6 The population in the community and the ecosystem 31 5 Fishing 34 5.1 Fishing equipment 34 5.2 Fishing areas 35 5.3 Fishing seasons 35 5.4 Fishing operations and results 36 6 Protection and management 36 6.1 Regulatory (legislative) measures 36 6.3 Control or alteration of chemical features of the environment 36 6.4 Control or alteration of the biological features of the environment 39 7 Pond fish culture 39 7.1 Procurement of stock 39 7.2 Spawning 39 Synop'is of Biological Data for the Winter Flounder, Pseudopteuronectes americanus (Walbaum) GRACE KLEIN-MacPHEE' ABSTRACT This monograph contains a synopsis of selected pertinent papers covering biological and tech- nical data of the winter flounder, Pseudopleuronecte8 americanus, including life history, taxonomy, physiology, disease, ecology, population dynamics, commercial and sports fishery, behavior, environ- mental effects, and culture. One hundred and fifty-four published reports and 12 unpublished reports are covered. Twenty-one figures are included. Literature up to and including 1976 is covered. I IDENTITY ClassOsteichthys OrderPleuronectiformes (Heterosomata) 1.1 Nomenclature FamilyPleuronectidae After Jordan et al. 1930:227 and Norman 1934:345. Generic (data from Norman 1934) 1.11 Valid scientific name Pseudopleuronectes. Bleeker 1862. Versl. Akad. Wet. Amsterdam, xiii, p. 428. Pseudopleuronectes americarws (Walbaum) [Pleuronectes planos Mitchill]; Norman 1933, Ann. Mag. Nat. Hist. (10) xi, p. 220. 1.12 Subjective synonomy Limandella. Jordan and Starks 1906. Proc. U.S. Nati. Mus., xxxi, p. 204. Pleuronectes. Schöepf 1788. Schrift. Ges. Nat. Freunde [Pleuronectes vokohamae Günther.] Berlin, VIII, p. 148. Pleuronectesamericanus Walbaum1792.Artedi GenericBody ovate, compressed. Eyes on right side Ichth.(3), ed.2,P. 113 (based on the flounder of separated by narrow naked or scaled ridge, upper eye Schöepf). close to edge of head; postocular ridge, if present, rugose; Pleuronectes planus Mitchill 1814. Rep. Fishes New snout and eyeballs not scaled. Olfactory laminae, paral- York, p. 8. lel, without rachis. Mouth moderate sized, length of Platessa plana. Storer 1893. Boston J. Nat. Hist,, ii, p. maxillary on blind side less than one-third that of head, 475; Rep. Ichth. Mass., p. 140. jaws and dentition stronger on blind side, no more than Platessa pusilla De Kay 1842. Nat. Hist., New York six teeth on ocular side of either jaw, teeth compact in- (Fish), p. 296, pI. xivil; fig. 153 (New York). cisorlike, close-set, sometimes forming continuous cut- Pseudopleuronectes planus. Bleeker 1862. Versi. ting edge, not enlarged anteriorly, uniserial in both jaws; Akad. Wet. Amsterdam, xiii, p. 428. vomer toothless. Gill rakers few, lower pharyngeals nar- Pseudopleuronectesamericanus.Gill1864.Proc. row,120-180 mm in length, slender, not much ap- Acad. Nat. Sci. Phila., xvi, p. 216. proximated anteriorly, inner edges evenly curved, each Pseudopleuronec tesdignabilis Kendall 1912. Bull. with widely separated rows of conical teeth. Dorsal fin U.S. Bur. Fish., xxx, (1910), p, 392, pl. lvii (Georges less than 85 rays beginning behind posterior nostril of Bank). blind side and above eye; all rays simple, some scaled on ocular side; tip of first interhaemal spine projecting in 1.2 Taxonomy front of anal fin which has less than 65 rays. Pectoral fin of ocular side usually larger than one on blind side; mid- 1.21 Affinities dle rays branched. Caudal fin 13 or 14 branched rays; caudal peduncle short to moderate in length. Scales Suprageneric small, adherent, imbricate (at least anteriorly) ctenoid or PhylumChordata cycloid; spinules, if present, short, few; no supplementary SubphyiumVertehrata scales, lateral line curved above pectoral fin, supratem- poral branch is present without posterior prolongations. Vent median or slightly on blind side between peivics. U.S. Environmental Protection Agency, Environmental Research Intestine narrow, elongate, with three or more coils; 3+1 Laboratory, South Ferry Road, Narragansett, RI 02882. pyloric appendages moderate or rather elongate. Three i species, one from Atlantic coast of North America; two Interorbital ridge nearly naked; tips of gill rakers from Japan. sharply pointed; 68-75 scales in lateral line; den- tal formula2 Specific O + 14-23 1. P. herzensteini. 2-6 + 19-24 Pseudopleuronectes americanus (Walbaum 1792) (Fig. 1). Interorbital ridge scaled; tips of gill rakers rounded or obtusely pointed; 75-90 scales in lateral line; dental formula 0-3 + 8-16 2. P. yokohamae. 0-4 + 12-20 II. Interorbital space flat, scaled, width one-third to one- half diameter of eye; postocular ridge not rugose; 78- 89 scales in lateral line 3 P. americanas. 1.22 Taxonomic status MorphoSpecies. 1.23 Subspecies See section 1.31 1.24 Standard common names, vernacular names Winter flounder, blackback, Georges Bank flounder, lemon sole, flounder, sole, flatfish, rough flounder, (Bige- low and Schroeder 1953). Plie rouge, carrelet (Leim and Scott 1986). 1.3 Morphology 1.31 External morphology Gill rakers 7-8 (lower anterior arch); lateral-line scales 78-89; fin rays, dorsal 59-71(73), anal 47-54(46), pec- toral 10-11 (5-7 branched); caudal 19 (13 branched); ver- tebrae 36 (10+26); pyloric caecae 3+1; dental formula 0-2 + 10-15(Norman 1934). See also Table 1. 0-2 + 10-17 1.32 Geographic variation In 1912 W. C. Kendall described the Georges Bank Figure 1.Adult winter flounder. flounder as a new species, Pseudopleuronectes dig- nabilis. He stated that the most conspicuous differential Typenot traced. characteristics of this "species" are shorter head, larger number of vertical fin rays, color, and larger size (Ken- Lateral line nearly straight, dorsal fin originatesop- dall 1912). There is also a different spawning season posite forward edge of eye and is nearly equal in height (April-May). throughout its length. Ventral fins alikeon two sides of Perlmutter (1947) compared counts of winter flounder body, both separated. Synopsis of the species is taken north and south of Cape Cod and from Georges Bank, He from Norman (1934:342). felt that Georges Bank flounder had significantly dif- ferent dorsal, pectoral, and anal fin ray counts showing Synopsis of the Species there was little mixing of this stock with other winter flounder stocks. I.Eyes separated by a ridge, which is nakedor scaled, width less than one-fourth diameter ofeye; postocular Dental formula occular aide + blind side (upper jaw) ridge rugose. occular side + blind side (lower jaw) 2 Table 1.-Comparison of fin ray counts of winter flounder by 8everal spawning time (Marcb'borfl) 'j investigators. the National Marine Fisheries Jsc. Pectoral Reference and showed that, in March, water Lenje:' Dorsal rays Anal rays rays locality 1.7° to 5.4°C This is higlia' Gloucester, Mass TheC0'':'i Kendall (1909) spawn at higher ternpa'1' .' 'j P. dignabilis ray number. Norman (i - 68-78 2 70.6 50-54 2 52.3 (Georges Bank) 61-67 î 64.7 46-502 48 P. anoericanus represent a distinct racs wit,' i . - as described by Kendall (1t.(' Perlmutter (1947) Lobell (1939) believec cc oic 63.97 ± 2.51 47.83 ± 1.82 9.84 ± 0.68North of Cape Cod Long Island Sound smc 64.05 ± 2.29 47.73 ± 1.88 10.08 ± 0.59South of Cape Cod Georges Bank localities occur siniulvr: 68.93 ± 2.53 51.30 ± 1.96 10.58 ± 0.62 (P. digna bilis) points relatively distant. X X Lux et al. (1970) 2 DISTRIBUTION 64.94 48.89 Cape Cod Bay (North) 66.87 50.42 East. Vineyard Sound (South) 2.1 Total area Date Georges Bank Atlantic coast of No tP 1963 69.53 51.94 (P. dignabilis) the offshore fishing baiPc 1964 69.58 52.14 1966 70.28 52.61 ter flounder is cornmc' North Shore of the Gul n Bay. The extremes of ¿' Lux et al. (1970) compared dorsal and anal fin ray of the Grand Banks. tii counts on winter flounder from inshore waters off gava Bay, Labrador (.cdcF Massachusetts north and south of Cape Cod and from Beaufort, N.C., the so'm LII Georges Bank. An examination of water temperature at (Hildebrand and Schrc fl. Y fl 800 75° 700 65° 60° // / OH? d SOR HORROR, BOO ROO 0*50? HOOK 5 O Ha RL ES ron AREA 21 (MAJOR FISHING AREAS 30° FOR FAOSTATISTICAL PURPOSES) Figure 2.-Range of winter flounder.