184 Clupeiformes Meristic characters in species belonging to the order Clupeiformes whose adults or larvae have been collected in the study area. Families and genera are listed alphabetically. Rarely observed counts in parentheses. Sources: Munroe (2000; 2002a; 2002b). Also see species accounts. Family Dorsal Anal Pectoral Pelvic Species Vertebrae Fin Rays Fin Rays Fin Rays Fin Rays Clupeidae Alosa aestivalis 47–53 15–20 15–21 14–18 9–11 Alosa mediocris 53–55 15–20 19–23 15–16 9 Alosa pseudoharengus 46–50 12–18 15–20 14–16 10 Alosa sapidissima 55–57 (14)18–19(21) (18)21–22(25) 13–18 8–10 Brevoortia tyrannus 45–50 18–24 18–24 13–19 7 Clupea harengus 52–62 (16)17–19(22) (15)17–19(21) 13–21 6–10 Dorosoma cepedianum 47–51 10–15 25–37 14–17 7–10 Dorosoma petenense 43–44 11–15 17–27 12–17 (7)8 Etrumeus teres 46–50 15–22 10–13 14–16 8 Harengula jaguana 41–43 17–19 17–18 13–15 (7)8 Opisthonema oglinum 45–49 17–22 20–25 15–19 8–9 Sardinella aurita 45–49 16–19 16–20 15–16 7–8 Engraulidae Anchoa hepsetus 40–44 13–16 19–23 13–15 7 Anchoa mitchilli 38–44 13–17 23–30 11–12 7 Engraulis eurystole 43–45 13–16 15–18 14–16 7 Note: Three species of engraulids can best be distinguished by the relative positions of their dorsal and anal fins and by anal fin ray counts. These characters are most reliable in larvae >10 mm, juveniles and adults. Dorsal and anal fin origins can be almost opposite each other in adult A. mitchilli. Early Stages of Fishes in the Western North Atlantic Ocean 185 Clupeiformes Synopsis of characters for distinguishing larvae of the Clupeidae. "Dors-Anal" refers to number of myomeres between posterior dorsal and anterior anal fins. This number decreases at transformation in most species, as fin positions shift. Note that this number remains relatively stable through ontogeny in the genus Alosa. Notochord Notochord Total Preanal Predorsal Dors-Anal Pigment Pigment Myomeres Myomeres Myomeres Myomeres Dorsal Tip Ventral Tip Miscellanous Alosa aestivalis 47–53 42–45 – 11–13 No Yes Slim-bodied, small-eyed Alosa mediocris 53–55 38–42 – 7–8 In small larvae Yes – Alosa pseudoharengus 46–50 39–43 – 7–9 Yes Yes Deep-bodied, large-eyed Alosa sapidissima 55–57 41–47 – 9 to 71 No Yes – Brevoortia tyrannus 45–50 38–40, 30–31, 5 to 1 In small larvae Yes High D and A then 35–36 then 24–25 fin ray counts Clupea harengus 52–62 47, then 33 to 25 8–9 to 4 Varies Yes Late anal fin 41–46 ray formation Dorosoma cepedianum 47–51 39–44 – 10 to 71 No No Very high anal fin ray count Dorosoma petenense 43–44 36 – 10 to 71 No No Scattered pigment on caudal peduncle Etrumeus teres 48–50 39–40, 27–32, 5 to 2 No Yes Early teeth; low then 36 then 26 anal fin ray count Harengula jaguana 39–42 35, 25, 5 to 7 Yes If yes, Low myomere then 27 then 10 forms late count Opisthonema oglinum 45–49 40–41, 26–27, 8–10 to 5–7 No Yes High anal fin then 34–36 then 22–23 ray count Sardinella aurita 45–48 38–40, 26–27, 7–8 to 5 No Yes – then 34 then 18 1 Determined from illustrations; need confirmation Patterns of ventral pigment, posterior to cleithrum, in larvae of four species of Alosa. These patterns may be incomplete in many larvae. (Walsh et al., 2005, modified from Sismour, 1994.) Walsh et al., (2005) also provide a size- dependent key to larvae of these four spe- cies (plus Dorosoma cepedianum) from the southern part of the study area (Roanoke River, North Carolina). A. pseudoharengus A. aestivalis A. mediocris A. sapidissima 186 Alosa aestivalis (Mitchill, 1815) Clupeidae Blueback herring Range: Atlantic coast of North America from Nova Scotia to St. John's River, Florida Meristic Characters Habitat: Pelagic, schooling species, inhabiting coastal areas over the inner Myomeres: 47–53 continental shelf (deeper during winter), moving into brackish or fresh Vertebrae: 14–16+33–35 waters to spawn Dorsal fin rays: 15–20 Spawning: Adults migrate into coastal rivers during spring for spawning; begins in Anal fin rays: 15–21 late Apr, continues through May in southern part of range, as late as Sep Pectoral fin rays: 14–18 in Connecticut Pelvic fin rays: 9–11 Caudal fin rays: 7–8+10+9+6–7 Eggs: – Pelagic to semi-demersal, slightly adhesive – Diameter: 0.87–1.11 mm – Chorion: yellowish, semitransparent – Chorion; somewhat thick, inner surface corrugated – Oil globules small, unequal in size, scattered – Yolk: granular – Perivitelline space: wide Yolk-sac larva Larvae: – Hatching occurs at 3.1–5.0 mmTL; eye pigmented – Body elongate with long, straight gut; anus always posterior to dorsal fin – Sequence of fin ray formation: D–C–A, 1P , P2 (ossification sequence based on illustrations) – 11–13 myomeres between posterior dorsal and anterior anal fins – Discrete melanophores below pectoral fin base become a double line of pigment – Pigment along upper and lower gut in distinct rows – Notochord tip pigment present on ventral side only – Transformation occurs between 20 and 30 mm Note: 1. Slimmer and smaller-eyed than A. pseudoharengus 2. See comparative table in Clupeidae Introduction Early Juvenile: E. 45.0 mmTL Figures: Adult: H.L. Todd (Hildebrand, 1963a); Egg and yolk-sac larva: Mansueti and Hardy, 1967; A–B: Chambers et al., 1976; C: Ann S. Green (Hildebrand, 1963a; D: Nancy D. Patton (Hildebrand, 1963a); E: Mansueti and Hardy, 1967 References: Jones et al., 1978; Able and Fahay, 1998; Munroe, 2000; 2002b Early Stages of Fishes in the Western North Atlantic Ocean 187 Alosa aestivalis A. 12.0 mmTL B. 14.8 mmTL C. 20.5 mmTL D. 25.0 mmTL 188 Alosa mediocris (Mitchill, 1814) Clupeidae Hickory shad Range: Atlantic coast of North America from Bay of Fundy to Florida Habitat: Inner continental shelf, estuaries, tidal rivers; oceanic distribution during Meristic Characters winter not well known Myomeres: 53–55 Spawning: In tidal freshwater, late Apr through early Jun Vertebrae: 17+37 Dorsal fin rays: 15–20 Eggs: – Spherical, semi-demersal, slightly adhesive Anal fin rays: 19–23 – Diameter: 0.96–1.65 mm Pectoral fin rays: 15–16 – Chorion: transparent, thick, finely corrugated Pelvic fin rays: 9 – Yolk: densely segmented, amber Caudal fin rays: 9+10+9+7 – Oil globules: few, small – Perivitelline space: very wide Larvae: – Hatching occurs at 5.2–6.5 mm; eye pigmented – Body elongate with long, straight gut; anus always posterior to dorsal fin – Preanus length 80–86% TL Yolk-sac larva – Posterior gut with muscle-band striations – Flexion occurs at 10–15 mm – Sequence of fin ray formation: D–C, A, 2P –P1 (ossification sequence based on illustrations) – Pigmentation includes elongate melanophores along ventral surface of gut with few spots on dorsal surface in early larvae; later larvae have melanophores on ventrum from throat area to region above anal fin – Transformation occurs between 20 and 30 mm Note: 1. See comparative table in Clupeidae Introduction Early Juvenile: E. 35.2 mmTL Figures: Adult: H.L. Todd (Hildebrand, 1963a); Egg, yolk-sac larva and A–E: Mansueti, 1962 References: Jones et al. 1978; Able and Fahay, 1998; Munroe, 2000; 2002b Early Stages of Fishes in the Western North Atlantic Ocean 189 Alosa mediocris A. 15.8 mmTL B. 19.5 mmTL C. 24.3 mmTL D. 27.0 mmTL 190 Alosa pseudoharengus (Wilson, 1811) Clupeidae Alewife Range: Atlantic coast of North America from Newfoundland to South Carolina, most abundant between Gulf of Maine and Chesapeake Bay; also land- locked populations, Great Lakes and New York Meristic Characters Myomeres: 46–50 Habitat: Pelagic, schooling species, inhabiting coastal areas adjacent to fresh- Vertebrae: 46–50 water nursery areas; spends fall and winter in continental shelf waters Dorsal fin rays: 12–18 56–110 m deep, primarily off Southern New England, Georges Bank Anal fin rays: 15–20 and Gulf of Maine Pectoral fin rays: 14–16 Spawning: Adults migrate into coastal rivers during spring for spawning; larvae Pelvic fin rays: 9–10 and juveniles occur in estuaries throughout range, except those with Caudal fin rays: 10+9 (PrC) limited freshwater input. Eggs: – Demersal and adhesive – Diameter: 0.87–1.11 mm – Chorion: semitransparent and yellowish – Yolk: segmented – Oil globules: small, unequal in size, scattered – Perivitelline space: wide Larvae: – Hatching occurs at 3.1–5.0 mm; eyes pigmented Yolk-sac larva – Body elongate with long, straight gut; anus always posterior to dorsal fin – Preanus length about 80% TL – Posterior gut with muscle-band striations at sizes >10.0 mm – Flexion occurs at about 9.0 mmSL – Sequence of fin ray formation: D, C – A – 2P – P1 (ossification sequence based on illustrations) – Pigmentation includes row of spots on dorsal half of anterior gut, ventral surfaces of posterior gut; early larvae have rows of spots on dorsal and ventral surfaces of caudal peduncle; 1 large melanophore above base of pectoral fin; dorsolateral pigment appears in larger larvae – Transformation occurs between 25 and 30 mm Note: 1. Deeper-bodied and larger-eyed than Alosa aestivalis 2. See comparative table in Clupeidae Introduction Early Juvenile: – Larger juveniles have single, dark spot on side posterior to opercle – Sharp scutes form along midline of belly E. 42.0 mmTL Figures: Adult: H.L. Todd (Hildebrand, 1963a); Egg, yolk-sac larva: Mansueti and Hardy, 1967; A–B: Chambers et al., 1976; C: Norden, 1967; D: Ann S.