Presentation on theme: "Mobile Bay Lab ID Common Fish & Invertebrates Images and information taken from references at end – mostly TAMU."— Presentation transcript:
Mobile Bay Lab ID Common Fish & Invertebrates Images and information taken from references at end – mostly TAMU
Distinguishing Characteristics Body variable, more slender in northern populations. Snout fairly blunt, a little over 1/2 eye diameter; maxilla long, tip pointed, reaching beyond hind border of pre- operculum, almost to gill opening; panamensis-type gill cover canals. Anal fin rays rarely 28, its origin below unbranched dorsal fin rays. Anus nearer to pelvic fin tips than to anal fin origin. Similar Species Striped and dusky anchovies have longer snouts, wider stripes and different placements of dorsal and anal fins. Distinguishing Characteristics Body is ovate, very laterally compressed; color is silvery, dusky with yellow to green on back; fins are yellow, black spot on upper caudal peduncle; caudal peduncle with 6-12 weak scutes; mouth oblique, pointed; no paired caudal keels (ridges on sides of caudal peduncle); lateral line with strong anterior arch. Similar Species The black spot on the caudal peduncle easily distinguishes this jack except in the smallest of species. This jack and the bluntnose jacks are the only jacks with the upper caudal fin lobe longer than the lower lobe. The bumper can be distinguished from the bluntnose jack by the lack of strong line of scutes in the lateral line. The bumper only has a few scutes, mainly over the caudal peduncle. Distinguishing Characteristics Body large, elongate, longer than most gobies, almost eel-like; color purplish brown above, lighter below, 25-30 dark anteriorly directed stripes on upper body; 1 dorsal fin, long and continuous; pelvic fins united to form 1 fin; both dorsal and anal fins connected to tail fin base; eyes very small, near top of head; snout blunt; mouth oblique (slanting upwards), upper jaw extending to or past posterior margin of eye; tail lanceolate (long, pointed); scaled. Similar Species This is the largest goby. Other gobies have 2 dorsal fins. Bay anchovy Anchoa mitchilli Atlantic bumper Chloroscombrus chrysurus Violet goby Gobioides broussonetii
Distinguishing Characteristics Mainly marine but enters brackish estuaries with relatively high salinities Feeds mainly on small fishes and invertebrates. The dorsal and pectoral fins are equipped with a serrated erectile spine, both of which are venomous. Commonly caught by anglers along bridges, piers and catwalks. Flesh considered good; marketed fresh (Ref. 5217). Distinguishing Characteristics Hardhead catfish have six rounded barbels that stick out from their chins like whiskers. These barbels help the catfish find crabs, fish and shrimp in the muddy bays where they live. The dorsal and pectoral fins each are supported by a sharp, slime-covered barbed spine. The dorsal spine normally is held erect when the fish is excited and a tennis shoe or even a leather-soled shoe offers little protection. gafftopsail catfish Bagre marinus hardhead catfish Ariopsis felis Blue catfish Ictalurus furcatus Distinguishing Characteristics Catfish are long slender fish with barbels on the chin that look like long black whiskers. There are four pairs of barbels around the mouth, two on the chin, one at the angle of the mouth, and one behind the nostril. Blue catfish lack scales and possess an adipose fin, as well as a single, serrated spine in the dorsal and pectoral fins. The blue catfish is generally slate blue on the back to silvery/white on its underside and has a deeply forked tail. The number of anal fin rays is 30 to 35. The eyes of the blue catfish are placed in the lower half of the head..
Croaker are easily recognized by numerous short barbels on either side below the mouth and a sharply jagged preopercle. The latter can be painfully evident upon holding a croaker, as the fish tend to flare their opercles when disturbed or frightened. Croaker have a rather long head with an inferior mouth, appropriate for feeding on the bottom. They have silvery bodies with a series of copperish or brownish markings arranged in diagonal bars that tend to become less distinct as the fish grows. Pectoral and pelvic fins are bright yellow to orange. Atlantic cutlassfish Trichiurus lepturus Distinguishing Characteristics Body elongate, highly compressed, ribbon-like, no scales, color silver; lower jaw protrudes past upper jaw; mouth large, fang-like teeth; single dorsal fin running from head to almost end of body; pelvic fins and anal fins absent; caudal fin absent, tail end pointed; minute single spines along belly from anus to tail. Similar Species Other cutlassfishes in the Atlantic and Gulf have forked tails. The Atlantic cutlassfish has no caudal fin, tail just tapers to a point. Banded drum Larimus fasciatus Distinguishing Characteristics Body short and thick, laterally compressed; color grayish with dark vertical bars on sides; fins with some yellow; mouth oblique, 2nd anal spine thick; mouth supraterminal, lower jaw extending slightly past upper jaw; caudal fin rounded; lateral line extends onto caudal fin. Similar Species Small black drum have vertical stripes but not the oblique mouth, also has barbels on chin.
Distinguish ing Characteri stics Body short, very deep, extremely compressed; head sharply sloping, slightly concave in front of eye; lower jaw protrudes; color silvery, fins yellowish, dark area on top of caudal peduncle; 2nd dorsal fin lobe slightly elongate; dorsal and anal spines reabsorbed into body in large fish; pelvic fins short becoming rudimentary in larger fish; posterior scutes on lateral line weak; lateral line with strong moderately long anterior arch; no keels on caudal peduncle. Similar Species Lookdowns have deeper bodies and longer dorsal and anal fin lobes. Moonfish Selene setapinnis Bluefish Pomatomus saltatrix Distinguishing Characteristics Body elongate, compressed; color greenish blue on back, silvery on sides and belly; dark blotch at pectoral fin base; lower jaw thick, slightly projecting past upper jaw; 1st dorsal fin with short spines; 2nd dorsal fin long; anal fin slightly shorter than 2nd dorsal fin; prominent teeth, flat, triangular; caudal fin dusky; no scutes or keels on lateral line or caudal peduncle. Similar Species Similar to jacks but does not have the 2 detached spines in front of anal fin, the narrow caudal peduncle, grooves on the caudal peduncle, and no scutes on the lateral line. Distinguishing Characteristics Body short, very deep, extremely compressed; head sharply sloping, slightly concave below the eye; lower jaw protrudes; color silvery, fins yellowish, young with dark bar over eye and sometimes dark vertical bars; 2nd dorsal and anal fin lobes very elongate; 1st dorsal spines and pelvic fin rays long and filamentous in juveniles with filaments, spines and fins disappearing with age; posterior scutes weak; lateral line with strong moderately long anterior arch; no keels (ridges) on caudal peduncle. Similar Species Similar to moonfish but lookdown's body is deeper and 2nd dorsal and anal lobes very elongate. Lookdown Selene vomer
Dwarf sand perch Diplectrum bivittatum Distinguishing Characteristics Body slender, elongate; color pale yellow brown on back and sides, whitish below; 2 rows of dark horizontal interrupted bands on upper body; irregular vertical bars on sides; dark spot at base of caudal fin; wavy blue lines on head; dorsal fin orangish with white spots; mouth large; single group of spines at the angle of preopercle (vs. 2 groups); opercle with 3 flat spines; outer edge of opercle free. Similar Species Similar to the sand perch D. formosum which has 2 groups of spines on the preopercle margin, dwarf sand perch only has 1 group. Gulf Butterfish Peprilus burti Disting uishing Charact eristics Body deep, round, strongly compressed; color pale blue gray above, silvery with yellow tinges on sides; snout blunt, shorter than eye diameter; mouth small; dorsal and anal fins long, about the same length, anterior rays of both fins slightly elongate; pelvic fins absent; dorsal and anal spines small and sometimes obsolete; row of pores below anterior half of dorsal fin. Similar Species Similar to the harvestfish but anterior rays of dorsal and anal fins are only slightly elongated; butterfish have a row of pores below anterior half of dorsal fin (no pores in harvestfish).
Gulf menhaden Brevoortia patronus Distinguishing Characteristics Body deep, compressed; color blue-green above, sides and belly yellowish to silver; dark spot on shoulder, sometimes with a series of diffused spots behind shoulder spot; fins yellowish, caudal fin with dusky tips; typical herring mouth(short, deep lower jaw hidden by wide rounded upper jaw), upper jaw with frontal notch; belly with serrated keel; 2 rows of enlarged scales on back in front of dorsal fin; pelvic fin rounded, inner and outer rays about the same length; striated lines on opercle. Similar Species Differs from finescale menhaden by having striated lines on opercle, rounded pelvic fins (outer rays and inner rays about the same length); other herrings do not have 2 rows of enlarged scales on back in front of dorsal fin. Harvestfish Peprilus paru Distinguishin g Characteristi cs Body deep, round, strongly compressed; color pale blue gray above, silvery with yellow tinges on sides; snout blunt, shorter than eye diameter; mouth small; dorsal and anal fins long, about the same length, anterior rays of both fins very elongate; pelvic fins absent; dorsal and anal spines small and sometimes obsolete; no row of pores below anterior half of dorsal fin. Similar Species Similar to the gulf butterfish but anterior rays of dorsal and anal fins are very elongated (only slightly elongated in butterfish), butterfish with row of pores below anterior half of dorsal fin (no pores in harvestfish)
Hardhead catfish Ariopsis felis Distinguishing Characteristics Body elongate, the head is flattened dorsoventrally, the body is flattened laterally; body is scaleless; color bluish to gray above, white below; sharp, thick serrated spine in dorsal fin and both pectoral fins; 1st ray of dorsal and pectoral fins not elongated; adipose fin present; 3 pair of long round barbels on chin and mouth. Similar Species The gafftopsail catfish has 2 pair of flatted barbels (hardheads have 3 pair of round barbels), its 1st dorsal and pectoral fin rays are elongated; the blue catfish, a freshwater catfish that ventures into brackish waters, have 4 pair of barbels. Least puffer Sphoeroides parvus Distinguishing Characteristics Body elongate, globular, lower skin loose; color brown to gold (or yellow) on back and upper sides with several large black spots and many smaller lighter dots, lower sides and belly white; jaws form a beak with 2 teeth in upper jaw and 2 in lower jaw; no pelvic fins; dorsal and anal fins set far back near tail fin; small spiny projections (prickles) on belly; prickles on head and back. Similar Species Differs from the smooth puffer by having small spiny projections (prickles) on its head and back; differs from porcupinefishes by having a beak with 4 teeth (2 upper and 2 lower), porcupinefish have only 1 upper and 1 lower teeth in beak, porcupinefishes also have large spines, least puffer has small prickles.
Hogchoker Trinectes maculatus Distinguishing Characteristics Body round, flattened laterally, both eyes on right side of body (right-eyed), covered with scales; color brown, blotchy with distinct vertical lines; pectoral fins absent on both sides of body; upper eye in advance of lower eye; yellow color on fins. Similar Species Lined sole has no distinct lines on body and has pectoral fin on ocular side; fringed sole has pale body with thick distinct black lines, no scales and eyes are aligned. Pinfish Lagodon rhomboides Distinguishing Characteristics Body moderately deep, compressed, color silver, olive, bluish with yellow horizontal lines on sides; dark spot on shoulder; 6 diffuse vertical bars on sides; mouth small; front teeth in both jaws incisor-like, directed outward, teeth deeply notched; posterior nostril oval; 1st dorsal spine small, projected forward; no scales between eye and mouth; preopercle not serrated. Similar Species Differs from the pigfish by having a shorter snout, larger eye and a shoulder spot (not present on the pigfish).
Scaled sardine Harengula jaguana Distinguishing Characteristics Body moderately deep, compressed; color green-blue above, sides and belly silvery, faint spot behind opercle; dorsal and caudal fins yellowish with dusky tips; typical herring mouth (short, deep lower jaw hidden by wide rounded upper jaw); belly with serrated keel; no frontal notch in upper jaw; no enlarged scales on back in front of dorsal fin; shoulder under opercle with 2 small lobes. Similar Species Scaled sardine does not have an elongated, filamentous last dorsal ray and it has 2 lobes on shoulder under opercle. Distinguishing Characteristics Body moderately elongate, compressed; color green-blue above, sides and belly silvery, faint spot behind opercle; dorsal and caudal fins yellowish with dusky tips; typical herring mouth (short, deep lower jaw hidden by wide rounded upper jaw); belly with serrated keel; no frontal notch in upper jaw; no enlarged scales on back in front of dorsal fin; last dorsal ray elongated, filamentous; shoulder inside opercle with no lobes. Similar Species Threadfin shad, gizzard shad and Atlantic thread herring are the only herrings (off Texas) where the last dorsal ray is elongated and filamentous; threadfin shad has a terminal mouth (subterminal in gizzard shad), no frontal notch on upper jaw as in gizzard shad, also has no lobes on shoulder under opercle as in the Atlantic thread herring. Threadfin shad Dorosoma petenense
Bighead searobin Prionotus tribulus Distinguishing Characteristics Body elongate, head large with bony ridges and spines, width between eyes large; color dark with greenish-gray mottling on back, some black markings or dark and light spots; black oblique bar below soft dorsal fin; belly white; 1st dorsal with black spot; pectoral fin large, wing-like, lower 3 rays free, finger-like; pectoral fins dark with lighter bands, no spots, sometimes with yellow edges, white edge on underside of pectoral fin. Similar Species Dark pectoral fin with lighter banding with no spots and the oblique bar under soft dorsal fin distinguish this species from other searobins; flying gurnards are similar to searobins but their pectoral fins do not have free rays. Distinguishing Characteristics Body elongate, head large with bony ridges and spines; width between eyes narrow; color reddish brown above, belly and lower sides white; no black oblique bar below soft dorsal fin; 1st dorsal with black spot with white area underneath; 2nd dorsal fin orangish with white spots; pectoral fin large, wing-like, lower 3 rays free; pectoral fins dark with white spots with blue margins, dark blotch on lower edge, sometimes with yellow edges; underside of pectoral fin dark with white posterior margin; anal fin dusky with white margin. Similar Species White spots on a dark pectoral fin and peculiar white and black spot on dorsal fin distinguish this species from other searobins; flying gurnards are similar to searobins but their pectoral fins do not have free rays. Bigeye searobin Prionotus longispinosus
Rough silverside Membras martinica Distinguishing Characteristics Body elongate; snout somewhat pointed; mouth oblique; color pale yellow to off-white, lateral silvery stripe; white swimbladder apparent through flesh; 2 dorsal fins, 1st dorsal fin with spines only; pectoral fins sit high on sides of body; pigment on back in parallel rows; scales rough to touch; caudal fin with dusky margin. Similar Species The inland silverside has scales on back outlined with dark pigment and its scales are smooth to the touch; anchovies have a snout that protrudes past the mouth. Spot Leiostomus xanthurus Distinguishing Characteristics Body anteriorly deep; compressed; color silvery gray, darker above; oblique streaks on upper sides; dark spot on upper end of gill plate; dorsal fin with deep notch; caudal fin truncate to emarginate; lateral line extends onto caudal fin. Similar Species Atlantic croakers have a golden color to them, body not as deep as spots, caudal fin is double emarginate; no shoulder spot. Distinguishing Characteristics Body elongate, cylindrical, laterally compressed posteriorly; head flat on top; color bluish-black on back, silvery on sides; no dark spots on scales, no horizontal stripes on sides; dark blotch at base of pectoral fin; pigment around eye limited to upper iris; gold spot on shoulder (upper opercle). Similar Species Differs from the striped mullet by having no horizontal stripes, pigment on eye limited to upper iris, has a gold spot on shoulder; juveniles can be distinguished by counting elements (spines and rays) in anal fin (12 for white mullet, 11 for striped mullet). Gulf menhaden Brevoortia patronus
Southern kingfish Menticirrhus americanus Distinguishing Characteristics Body elongate and moderately compressed; color silvery to gray, sometimes with yellow tinge; darker mottling on sides; pectoral fins dark on posterior margin; 1 barbel on chin; dorsal fin with deep notch; inside of gill plate dusky; scales on chest about the same size as those on sides; mouth subterminal; caudal fin pointed (juveniles) or S-shaped (adults). Similar Species Gulf kingfish has no darker markings on side and inside of gill plate is pale; northern kingfish has more distinct diagonal bars and a horizontal stripe on sides, its 2nd dorsal spine is elongate and reaches past the beginning of the soft dorsal rays Silver seatrout Cynoscion nothus Distinguishing Characteristics Body elongate and moderately compressed; color grayish above, silvery below, no spots; lower jaw protruding slightly, mouth supraterminal; inside of mouth orange; 2 fang-like teeth on tip of upper jaw; dorsal fin with deep notch; caudal fin S-shaped in adults, pointed in juveniles; 1/2 of soft dorsal fin base covered in scales; anal fin base about the same length as eye diameter. Similar Species Sand and silver seatrout are difficult to distinguish, the best way is to count the anal fin rays, silver seatrout have 9 rays, sand seatrout have 10 or 11 rays; sand seatrout have scales covering 1/3 of the soft dorsal fin base (1/2 or more in silver seatrout); spotted seatrout have spots on sides.
Southern flounder Paralichthys lethostigma Distinguishing Characteristics Body oval, almost football-shaped, flattened laterally; both eyes on left side of body (left- eyed); color brown sometimes with light and dark blotches but no distinct spots, white underneath (right side); high arch in anterior lateral line just behind head; forehead flat; eyes far apart; mouth oblique, large, upper jaw reaching to behind eye. Similar Species Gulf and ocellated flounders both have high arch in lateral line like the southern flounder, but both have distinct spots; southern has no distinct spots; only Gulf flounder gets near the size of the southern flounder. Inshore lizardfish Synodus foetens Distinguishing Characteristics Body very elongate, cylindrical; snout pointed; mouth large, extending posteriorly well beyond eye; needle-like teeth in both jaws, tongue and roof of mouth with teeth (rough patches); color golden brown above, whitish below, young with diamond- shaped blotches on the sides; adipose fin present; 1 dorsal fin, no spines, at about center of back; inner rays of pelvic fins much longer than outer rays. Similar Species Offshore lizardfish has fleshy knob on its chin; in the largescale and smallscale lizardfishes, the rays of the pelvic fins are of equal length (inner rays much longer that outer rays in the inshore lizardfish).
Atlantic stingray Dasyatis sabina Distinguishing Characteristics Body dorsoventrally flattened; outer edges of pectoral fins rounded; snout pointed; color tan to light brown above; slender tail, longer than disk width, usually with 1 strong, serrated spine at base; no dorsal or caudal fins; low dorsal and ventral folds on tail; a row of thorns along midline of back. Similar Species The bluntnose stingray as well- developed dorsal and ventral tail folds; the southern stingray has angular pectoral fins; roughtail stingray has more body spines. Bonnethead shark Sphyrna tiburo Distinguishing Characteristics Body elongate, laterally compressed; head flattened dorsoventrally, shovel-shaped, evenly rounded with no indentations, lateral expansions short; 1st dorsal fin high and narrow; 2nd dorsal fin smaller than 1st; teeth small and smooth, rear teeth molar-like; color gray above, pale to white below. Similar Species Other hammerheads have hammer-shaped heads where lateral extensions are longer, the contour of the head has indentations (smooth in bonnetheads).
Atlantic sharpnose shark Rhizoprionodon terraenovae Distinguishing Characteristics Body elongate; snout moderately long and pointed; color brown to gray above, pale below, a few scattered white spots on sides; the origin of the 2nd dorsal fin is posterior to the origin on the anal fin; no interdorsal ridge; 2nd dorsal fin and caudal fin with dark edges; labial folds (in the corners of the mouth) well-developed, long; upper teeth angular, notch on outer edge, inner edge finely serrated. Similar Species This is the only shark with its dorsal fin origin behind to anal fin origin, except for the smalltail shark which has short labial furrows and strongly serrated teeth.
Sea nettle Chrysaora quinquechirrha Distinguishing Characteristics Bell gelatinous, bowl-shaped, broader than deep; color is translucent to opaque white, usually has small white spots and radiating reddish brown stripes; the bell is slightly indented (notched) in 8 spots, 1 long tentacle emerges from each notch, several shorter tentacles emerge from between the notches, 24-40 tentacles in all; 4 long convoluted oral arms hang beneath the bell; sting is moderate to severe. Similar Species The radiating brown stripes distinguish this jelly from others. Sand dollar Mellita quinquiesperforata Distinguishing Characteristics Body round, flat with an upward slope towards the center, rigid; no arms; color usually green but can be tan, brown or gray; body covered with short spines; bottom side flat with mouth in the center and anus to the side; mouth with 5 jaws with teeth arranged in a circle (called Aristotle's lantern); bottom with tube feet; top with specialized tube feet, called petalloids, each with 2 rows of pores arranged in the shape of a 5-petal flower; 5 oval-shaped holes (lunules) through skeleton, 1 pair near the top, 1 pair near the bottom and 1 large hole between bottom pair (young may not have 5 holes yet, notches mark where lunules will eventually develop). Similar Species This is the only species of sand dollar found off Texas.. Another species, M. tenuis, occurs in the Gulf of Mexico but is limited to east of the Mississippi River. It has much smaller spines than our sand dollar.
Clypeaster"cake urchins" or "sea biscuits" Distinguishing Characteristics Body star-shaped with 5 arms; color gray to light brown, dark gray or black stripe on the dorsal midline of each arm; upper surface of body covered with small plates, lower surface of arms contain tube feet used for locomotion; lower surface of disk (center part) contains the oral cavity (mouth). Similar Species Similar to the banded sea star, Luidia alternata, which has brown banding across arm on a lighter background. The gray sea star has no banding. Gray sea star Luidia clathrata
Brown shrimp Farfantepenaeus aztecus Distinguishing Characteristics Body shrimp-like; carapace smooth; color brown with some orange or yellow; no lateral spot between 3rd and 4th abdominal segment; 1st abdominal segment overlaps the 2nd segment; rostrum with 8-9 teeth above, 2 teeth below; groove an both sides of rostrum extending almost to posterior edge of carapace; dorsolateral grooves on the last abdominal segment broad and well defined; brown pigment on uropods (tail fans) more concentrated on ends; 1st 3 pair of walking legs chelate (with claws). Similar Species Similar to pink shrimp but pink shrimp have a lateral spot between 3rd and 4th abdominal segment and their dorsolateral groove is so narrow that a fingernail cannot fit into it. Brown shrimp differ from white shrimp by having dorsolateral grooves on the last abdominal segment and the dorsolateral grooves on the carapace extend nearly to posterior margin of carapace. Pink shrimp Farfantepenaeus duorarum Brown shrimp Distinguishing Characteristics Body shrimp-like; carapace smooth; color pale to dark pink; dark lateral spot at junction of 3rd and 4th abdominal segment; 1st abdominal segment overlaps 2nd abdominal segment; rostrum with 8-9 teeth above, 2 teeth below; groove an both sides of rostrum extending almost to edge of carapace; dorsolateral grooves on the last abdominal segment narrow (cannot put fingernail in groove); brown pigment on uropods (tail fans) are evenly dispersed, not concentrated on ends; 1st 3 pair of walking legs chelate (with claws). Similar Species Similar to brown shrimp but brown shrimp do not have a lateral spot between 3rd and 4th abdominal segment and their dorsolateral groove is broad enough for a fingernail to fit into it. Pink shrimp differ from white shrimp by having dorsolateral grooves on the last abdominal segment and the dorsolateral grooves on the carapace extend nearly to posterior margin of carapace. Also white shrimp do not have the lateral spot. Pink shrimp
White shrimp Litopenaeus setiferus Distinguishing Characteristics Body shrimp-like; carapace smooth; color translucent bluish white; no lateral spot between 3rd and 4th abdominal segment; 1st abdominal segment overlaps the 2nd segment; rostrum with 7-9 teeth above, 2 teeth below; grooves on sides of rostrum short, not extending past anterior half of carapace; no dorsolateral grooves on the last abdominal segment; dark blotch on distal end of uropods (tail fans), distal margins outlined with green pigment; 1st 3 pair of walking legs chelate (with claws). Similar Species Differs from other penaeids by not having dorsal grooves on last abdominal segment and dorsal groove on carapace not extending past anterior half of carapace. Mantis Shrimp (Squilla empusa)
Portly spider crab Libinia emarginata Distinguishing Characteristics Carapace round, narrowing at the anterior end into an extended, slightly forked rostrum (extended snout); color brown; body tubercled with spines and bumps; row of 8-9 spines down the center of the carapace, the anterior few more like bumps than spines; thin walking legs; tips of legs with curved points; claws small. Similar Species It's difficult to distinguish between the portly and the longnose spider crabs, except by counting the spines (bumps) down the center of the carapace. The portly has 8-9 (the anterior one just small bumps) and the longnose has less than 7 (usually 6).The longnose has a more tear-drop shape, the portly more rounded. Longnose spider crab Libinia dubia Distinguishing Characteristics Carapace round, narrowing at the anterior end into an extended, slightly forked rostrum (extended snout); color brown; body tubercled with spines and bumps; row of 7 or less (usually 6) spines down the center of the carapace; thin walking legs; tips of legs with curved points; claws small. Similar Species It's difficult to distinguish between the portly and the longnose spider crabs, except by counting the spines (bumps) down the center of the carapace. The portly has 8-9 (the anterior one just small bumps) and the longnose has less than 7 (usually 6).The longnose has a more tear-drop shape, the portly more rounded.
Blue crab Callinectes sapidus Distinguishing Characteristics Carapace broader than long, compressed; color olive green to brown dorsally, yellowish to white underneath; legs olive, bluish or brown; claws are long, palms with blue and white coloration, fingers blue in adult males, red or orange in adult females, juveniles with white fingers with red spot at base of fingers; last pair of legs flattened into paddle-shaped appendages; 9 pair of spines (including the outer orbital spines) along the lateral edges of the carapace, the most posterior pair (called the lateral spines) being about 3-4 times as long as the others; 4 low blunt spines between the ocular orbits, (eye sockets), including the inner orbit spines; spines on the inner margins of merus (2nd segment from the claws) and outer carpus (segment next to claw), no spine on inner dorsal carpus. Similar Species Lesser blue crabs look similar, but have 6 low spines between the ocular orbits, the center pair extremely small, fingers on claws never red, juveniles with bluish spot at base of fingers.
Atlantic brief squid Lolliguncula brevis Distinguishing Characteristics Body (mantle) cylindrical, stout, bluntly rounded at tip; lateral fins short, broad, rounded, wider than long; eyes nearly lateral; has a funnel behind the eyes; 8 short arms (shorter than mantle length) with sucker on the undersides extending the length of the arms; 2 longer tentacles with suckers only on the ends, ends spatulate shaped; mouth with beak-like teeth; color translucent with many purple-red pigment cells (chromatophores) on entire body. Similar Species The brief squid mantle is floppy, not as slender as other squids, has a blunt mantle tip, and is usually not as pigmented as the other squids. Longfin inshore squid Loligo pealeii Distinguishing Characteristics Body (mantle) cylindrical, long, slender, tip pointed, lateral fins longer than wide, exceeding 50% of mantle length in specimens with mantle length > 7 cm (2 3/4 in); outer edges at a blunt angle (not rounded), sides nearly straight; eyes nearly lateral; has a funnel behind the eyes; 8 short arms (shorter than mantle length) with sucker on the undersides extending the length of the arms; 2 longer tentacles with suckers only on the ends, ends spatulate shaped; mouth with beak-like teeth; color translucent with many reddish pigment cells (chromatophores) on entire body; the internal pen has a vane width/rachis width ratio of 2.4 or greater, edges are usually curved, usually with no ridges. Similar Species The longfin inshore squid is more slender and firm than the brief squid, its mantle tip is hard and pointed; its fins are long and rhomboidal shaped, it usually more chromatophores than the brief squid; It is more slender with longer fins (usually >50% of mantle length) than the arrow squid; its pen is wider at the vane usually with curved edges and rarely with ridges; the pen of the arrow squid is narrower usually with straight edges and usually has ridges.
Texas coquina Donax texasianus Distinguishing Characteristics Bivalve (2 shells); shell sturdy, almost triangular in shape, moderately inflated, anterior end longer, both anterior and posterior ends somewhat angular; color whitish with some light blue, pink or yellow; rarely rayed; fine concentric growth lines and fine radial ribs; ribs lightly beaded on posterior end; ventral posterior margin crenulate (scalloped), inside ventral margin crenulate. Similar Species Similar to the variable coquina, but the Texas coquina is smaller (<0.8 cm), more inflated, ventral margin is more rounded, left valve overlaps right valve on ventral margin, and its posterior ribs are lightly beaded..