(DRAFT) - Taxonomy
                              Species puffer, northern
                                 Species Id M010500
                                   Date 26 AUG 96



TAXONOMY

NAME - puffer, northern OTHER COMMON NAMES - northern puffer, balloonfish, bellowsfish, blowfish, blower, bottlefish, globefish, puffer, Rabbitfish, Sea Squab, Swell Belly and Swell Toad ELEMENT CODE - CATEGORY - Fish PHYLUM AND SUBPHYLUM - Vertebrata, Craniata CLASS AND SUBCLASS - Osteichthyes, Actinopterygii ORDER AND SUBORDER - Tetradoniformes, Tetradontoidei FAMILY AND SUBFAMILY - Tetradontidae, GENUS AND SUBGENUS - Sphoeroides, SPECIES AND SSP - maculatus, SCIENTIFIC NAME - Sphoeroides maculatus AUTHORITY - Bloch and Schneider TAXONOMY REFERENCES - 181 COMMENTS ON TAXONOMY - Objective synonymy: Tetro hispidus, Schopf, 1974 Tetrodon hispidus var. maculatus, Bloch and Schnieder, 1801 Tetrodon turgidus, Mitchill, 1815 Stenometopus binummulatus (Bibron), Troschel, 1856 Gastrophysus turgidus, Gill, 1873 Cilichthyes turgidus, Yarrow, 1977 Cirrisomus turgidus, Jordan and Gilbert, 1878 Spheroides maculatus, Jordan and Edwards, 1886 Orbidus maculatus, Moore, 1894 Tetradon maculatus, Nochols and Breder, 1927 Tetrodon maculatus, Truitt, Bean, and Fowler, 1929 Sphoeroides maculatus, Jordan, Evermann, and Clark, 1930 Sphaeroides maculatus, Fraser-Brunner, 1943 Tetrodon punctatus, LeDanois, 1959 Etymology: The generic name is derived from the Greek words meaning sphere and resemblance. It is based on the front view of the fish. The specific name, maculatus, is Latin, meaning spotted. Other common names include balloonfish, bellowsfish, blowfish, blower, bottlefish, globefish, puffer, rabbitfish, sea squab (market name), swell belly, and swell toad *181*. Taxonomy - 1
                                  (DRAFT) - Status
                              Species puffer, northern
                                 Species Id M010500
                                   Date 26 AUG 96



STATUS

Coded Status Sport Fish Commercial Commercial/consumption REFERENCES FOR STATUS - 181 COMMENTS ON STATUS - The northern puffer became an important food fish as a result of meat rationing during World War II which promoted the coastal fisheries. The largest catch from the New York area was almost 1,060 t in 1945. Thereafter, the catch dropped off to less than 430 t, increased to another high with almost a million pounds landed in 1963, and then decreased again to 41 t in 1969. The decrease in puffer landings in New York was attributed to the development of the Chesapeake Bay fishery which in turn caused a large drop in prices. The decrease in the puffer catch from the bays along the eastern portion of Long Island may be attributed to overfishing, the decline of pound net fishing, or natural causes. The decrease has been considerable, from a high in 1963 of over 385 t (more than 90% of the total commercials landings of puffer in New York) to 41 t in 1969 (less than 35% of the total puffer landings in New York). Results based on the recent increase in fishery activity for puffers in Long Island Sound and the ocean, suggest that the fishery may virtually be an underexploited resource in state waters. This fish is considered an important species comprising the New York coastal export fishery. However, puffers did not make up a large portion of export fishery in the bays of eastern Long Island and therefore did not affect the commercial fishery there. The rise in the 1960 to 1963 commercial landings is attributed to an actual abundance increase. This was substantiated by sport fishery studies. From 1960 to 1962 the sport catch in Great South Bay rose from 58,000 to about 314,000 fish. The sport catch in 1963 was slightly less than the previous years. Results from beach seine catches along the South Shore of Long Island in 1962 and 1963 showed puffers comprised about 66% of the catch. In 1961, puffers made up less than 1% of the catch. Northern puffer sold in the fresh fish trade are dressed, skinned, and the meat sold under the market name of sea squab. The protein quality of meat is about equal to beef. In periods of abundance when supply exceeds the market demand, some are frozen for future sale. Some are also used for reduction into fish meal *181*. Status - 1
                               (DRAFT) - Distribution
                              Species puffer, northern
                                 Species Id M010500
                                   Date 26 AUG 96



DISTRIBUTION

Distribution - 1
     

HABITAT ASSOCIATIONS

NATIONAL WETLAND INVENTORY CODES NWI NWICLS NWIMOD NWISPEC Marine FL. V 1 Marine, intertidal FL. V 1 Estuarine FL1 V 1 Estuarine FL3 V 1 Estuarine FL2 V 1 Marine FL. V 1 Marine, intertidal FL2 V 1 REFERENCES FOR NWI - 181 COMMENTS ON HABITAT ASSOCIATIONS - Adult puffers are coastal fishes found from the tide line in estuaries to a depth of only a few fathoms offshore. Where the range of the northern puffer overlaps that of the southern puffer (S. nephalus) off northeastern Florida, the former is found in open and deeper waters and the latter inhabit estuaries. Northern puffers are considered demersal, however, they are known to actively move throughout the water column. They prefer sandy substrate, near to or amid sea wrack, but are also found over silt, mud, shell, or gravel bottom. Puffers spawn throughout their range of abundance in shoal water, close to shore. The larvae are pelagic. Juveniles are semidemersal and inhabit the intertidal zone over smooth bottom *181*. Habitat Associations - 1
                                (DRAFT) - Food Habits
                              Species puffer, northern
                                 Species Id M010500
                                   Date 26 AUG 96



FOOD HABITS

TROPHIC LEVEL - OMNIVORE REFERENCES FOR TROPHIC LEVEL - 181 LIFESTAGE FOOD FOOD PART General Molluscs Not Specified General Bivalve Molluscs Not Specified General Crustaceans Not Specified General Echinoderms Not Specified General Sea/Heart Urchins Not Specified General Annelids Not Specified General Gastrotriches Not Specified General Bryozoans Not Specified General Sponges Not Specified General Sea Squirts Not Specified General Cyanophyta Not Specified General Phaeophyta Not Specified General Rhodophyta Not Specified General Isoptera Not Specified General Cirripeds Not Specified General Malacostraca Not Specified REFERENCES FOR GENERAL FOOD - 181 COMMENTS ON FOOD - The following is a composite list of dietary constituents as reported by various sources: Pelecypods (including scallops, jingle shells, clams, Solemya sp., oysters, mussels, razor clams), gastropods (including Haminoea), barnacles (Balanus sp.), limpets, crabs (including blue, mud), isopods, hermit crabs, shrimp (including mantis), cumaceans, amphipods, caprellids, sea urchins (including Arbacia sp.), sea urchin spines, tests of sea urchins (Moira atropos), annelids, worm tubes, bryzoa, sponges, sea anemones, sea squirts, seaweed, algae, and watermelon seed. Throughout their range puffers appear to be opportunistic feeders, preying mainly on available invertebrates. Their powerful jaws enable them to crush and devour anything they capture. When preying on small crabs, puffers attempt to paralyze the crustacean by making the first bite in front so as to sever the nerve ganglion. Puffers are known to unite in a group to attack a blue crab. Feeding occurs during daylight as puffers are nocturnally inactive *181*. Food Habits - 1
                         (DRAFT) - Environment Associations
                              Species puffer, northern
                                 Species Id M010500
                                   Date 26 AUG 96



ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult LIM = Limiting RA = Resting Adult J = Juvenile FA = Feeding Adult RJ = Resting Juvenile BA = Breeding Adult FJ = Feeding Juvenile P = Pupae L = Larvae E = Egg RL = Resting Larvae FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS RA Estuarine habitat zone: specified in comments RA Bottom Type [Aquatic]: Mud or silt RA Bottom Type [Aquatic]: Sand RA Bottom Type [Aquatic]: Gravel G Relation to Substrate: Unattached - normally free living RA Water Temperature: Specified in Comments RA RJ Bottom Type [Aquatic]: Specified in Comments RJ Estuarine habitat zone: specified in comments RJ Water Temperature: Specified in Comments RJ RL Estuarine habitat zone: specified in comments RL Water Temperature: Specified in Comments RL LIM Water Temperature: Specified in Comments BA Bottom Type [Aquatic]: Specified in Comments REFERENCES FOR ENVIRONMENTAL ASSOC_ - 181 REFERENCES FOR LIMITING ENVIRONMENTAL ASSOC_ - 181 REFERENCES FOR RESTING ADULT ENVIRONMENTAL ASSOC_ - 181 REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 181 REFERENCES FOR RESTING JUVENILE ENVIRONMENTAL ASSOC_ - 181 REFERENCES FOR RESTING LARVAE ENVIRONMENTAL ASSOC_ - 181 COMMENTS ON ENVIRONMENTAL ASSOCIATIONS - HABITAT ZONE: Northern puffers are coastal fishes found from the tide line in estuaries to a depth of only a few fathoms offshore. SUBSTRATE: Northern puffers prefer sandy substrate but are also found over silt, mud, shell, or gravel bottom. TEMPERATURE: Northern puffer are found in water temperatures ranging from 10.0 to 34.1 deg C. SALINITY: Puffers are found in salinities normal to a coastal and estuarine environment. Adults are found in salinities from 6.7 to 34 oo/o *181*. Environment Associations - 1 (DRAFT) - Environment Associations Species puffer, northern Species Id M010500 Date 26 AUG 96 COMMENTS ON RESTING ADULT ENVIRONMENTAL ASSOC_ - HABITAT ZONE: Northern puffers are coastal fishes found from the tide line in estuaries to a depth of only a few fathoms offshore. SUBSTRATE: Northern puffers prefer sandy substrate but are also found over silt, mud, shell, or gravel bottom. TEMPERATURE: Northern puffer are found in water temperatures ranging from 10.0 to 34.1 deg C. SALINITY: Puffers are found in salinities normal to a coastal and estuarine environment. Adults are found in salinities from 6.7 to 34 oo/o *181*. COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ - SUBSTRATE: A pair of puffers spawned in captivity. Eggs were deposited in sand.*181*. COMMENTS ON RESTING JUVENILE ENVIRONMENTAL ASSOC_ - HABITAT ZONE: Juvenile puffers are semidemersal and inhabit the intertidal zone. SUBSTRATE: Juveniles are found over a smooth bottom. TEMPERATURE: Juvenile puffers inhabit water temperatures from 16 to 26 deg C. SALINITY: Results of a survey show that juvenile puffers occur at salinities ranging from 12 to 2 0/00. They have been found at salinities up to 32.2 0/00 *181*. COMMENTS ON RESTING LARVAE ENVIRONMENTAL ASSOC_ - HABITAT ZONE: Northern puffer larvae are pelagic. TEMPERATURE: Larvae are found in water temperatures from 16 to 26 deg C. SALINITY: Larval puffers occur in a salinity range of 12 to 21 o/oo *181*. Environment Associations - 2
                               (DRAFT) - Life History
                              Species puffer, northern
                                 Species Id M010500
                                   Date 26 AUG 96



LIFE HISTORY

MORPHOLOGY: Head 2.7 to 3 in SL in adults, longer in subadults. Snout 1.7 to 2.1 in head, longest in adults. Eye 4 to 8 in head, but most often large, about 5 in head. Least bony interorbit flat to slightly concave, moderately broad, 2.4 to 4 in snout, usually about 3.3 in snout, about 6.5 in head. Dorsal fin origin opposite posterior edge of anal opening, slightly anterior to anal fin origin. Caudal truncate or slightly rounded but often with the uppermost rays longest. Length of exposed medial caudal rays about equal to snout length, about 2 in head. Pectoral fins moderately long, about 3.1 in snout, 2.5 in head. Dorsal rays 8, anal rays 7, pectoral rays usually 15 or 16 (rarely 17). Caudal rays 11, with the first upper and two lower rays usually unbranched. Pigmentation restricted to dorsolateral surfaces. Basal pigmentation is usually gray, which fades laterally. Poorly defined black spots cover the dorsal surfaces, and a vague dark bar transverses the interorbital region. A vague dark saddle extends transversely across the dorsum and passes through the base of the dorsal fin. Another similar saddle is present across the dorsal area of the caudal penduncle. Tiny jet-black pepper spots (about 1 mm in diameter) are scattered over most of the pigmented surface, and are especially evident on the cheeks. The flanks posterior to the pectoral fins are marked with 5-7 bars or elongate spots, usually vertical but occasionally slightly diagonal. These extend from the basal pigmentation of the dorsum to the lower margin of the flank, which lacks basal pigmentation. An intense black spot or bar is present at the posterior axil of the pectoral fin. Distinct bars or spots are usually absent on the flanks anterior to the pectorals. The base and distal half of the caudal may be dusky with a lighter central region, but often the entire caudal may appear uniformly dusky. The other fins are nearly devoid of pigment. Lappets are never present. All body surfaces anterior to the anus or anal fin origin and dorsal origin are densely covered with strong, close-set prickles except around the mouth. Almost the entire body is covered with small, slightly imbricate dermal structures which resemble fish scales. REPRODUCTION: The sexes are separate. Both sexes of puffers are sexually mature by their second growing season (i.e. age 1). Individuals as small as 88 mm are capable of spawning. Little is known about the breeding habits of the puffer, but they are probably polygamous and promiscuous. Egg fertilization is external. Gonads: The two gonads of a gravid puffer are dissimilar in that the left gonad is considerably larger than the right. The left ovary of a ripe female is 1.2 to 2.0 times larger and 1.6 times heavier than the right. However, a fecundity estimate can be made from either a single or combined ovarian sample as the eggs from both left and right ovaries are similar in size, ranging from 0.35 to 0.7 mm in diameter. This size range is conservative as the ovaries used in the study were treated with Gilson's fluid which causes egg shrinkage. No information was found describing the size difference for the male gonads. The fecundity of the puffer was first reported in 1928. The ovaries of a 265 mm fish were estimated to contain 176,000 eggs of similar size. A subsequent study showed this to be low by about 273,000 eggs. The total Life History - 1 (DRAFT) - Life History Species puffer, northern Species Id M010500 Date 26 AUG 96 fecundity increases both as a linear function of fish weight (Fecundity = -735.28 + 754.21 body weight in grams, the coefficient of determination r sqr = 0.86) and as a function of total length. The average relative fecundity is 5,204 eggs per gram ovarian net weight and 751 eggs per gram body weight. The amount of ovarian tissue when compared to the total body weight ranges from 6.3 to 19.2% with an average of 13.8%. Spawning: The spawning season is protracted, beginning in late spring in the Chesapeake and progressing northward throughout the entire summer and early fall. No information was found on spawning time south of Cape Hatteras. Mating has not been observed, but puffers probably spawn during daylight hours as they are known to be quiescent and lie on the bottom at night. A pair of northern puffers spawned while in captivity. The eggs were deposited in the sand, partially buried in a circular pattern with a diameter about equal to the length of the fish. There was no evidence of parental care of the eggs. The number of times puffers spawn during a spawning season is not known, but males may spawn more than once as they are ripe longer than females. Differences in sex ratios on the spawning grounds, which may be attributed to reproductive behavior, also indicate male spawn more than once. In both May and November, the ratio of males to females is 1:1. However, during the summer and early fall spawning season, this ratio changes to 1:3. When spawning peaks in June and July, males are least abundant. Eggs: The eggs are transparent, spherical, and invested with a smooth adhesive covering which is irregular in outline. They are demersal and readily become attached to any submerged object, or caked in a mass, owing to their adhesive nature. Where numbers adhere to the side of a container, close together and in a single layer, the adhesive envelope assumes a somewhat hexogonal appearance. The surfaces of the eggs are finely reticulated, rather resembling crepe paper. The eggs average about 0.874 mm in diameter, varying from .85 to .91 mm, while the enveloping adhesive coat increases the diameter to an average of about .954 mm. A large number of colorless oil globules of low refractive index are present in a foamy cluster, which averages about .34 mm in diameter, and a very faint olive tinge can be detected in the area in which the blastoderm is to develop. Embryos: The incubation period for puffer eggs is 112 hr at a water temperature of about 20 deg C. Two hr following fertilization, first cleavage is complete, and by 16 hr, the germ ring begins to form. At 24 hr, the embryo is distinct, and by hr 44 it is more than half way around the yolk. At 70 hr, vertebral somites are visible and scattered black chromatophores appear along each side of the embryo. The eyes are now distinct, the tail tip is free and the oil globules are located in the dorsal part of the yolk. At 90 hr, red and orange chromatophores appear along each side in addition to those of black already present. Several small black chromatophores are present on the tip of the snout and in the posterior portion of the iris. Numerous large black dendritic chromatophores are on the ventral surface of the yolk. The oil globules have combined in a few large droplets. Just prior to hatching the embryo increases in pigment content. The pigmentation extends posteriorly and ends abruptly midway between the vent and the tip of the notochord. Where the pigmentation Life History - 2 (DRAFT) - Life History Species puffer, northern Species Id M010500 Date 26 AUG 96 terminates, a brilliant opaque chrome yellow spot appears on the dorsal surface of either the embryo or the newly hatched larva. Larvae: Most larvae hatch tail first and are about 2.4 mm long. The small yolk sac still contains oil globules. Pigmentation on the body consists of many brilliant red, orange, yellow, and black chromatophores. Numerous small tubercles are present over most of the body. Twenty-four hours after hatching the nostrils are visible, the lateral line organs begin to appear, the pectorals are distinct, and the eye pupil is black. At 48 hours the yolk material is reduced, the mouth and vent are open and green pigmentation appears, particularly in the iris. After 72 hours the mouth is functioning. When the larvae are 7 mm long, they possess many diagnostic adult characters, and are capable of inflation. They are, however, more thick in stature than adults, have larger eyes, and lack the adult color pattern. Juveniles: The general morphology of juvenile fish as such is similar to that of adults, but there are differences in pigmentation patterns between the two. Young fish lack the dark black "pepper" spots which appear when the individual is from 40 to 100 mm long. The large dark lateral marks on the juveniles become oblong in shape and characterize adult patternization. The development of prickles occurs in individuals as small as 10 mm. ADULTS: Hardiness: Laboratory experiments on the effect of sudden changes in water temperature indicate that puffers can withstand the recovery from heat shock better than cold shock. The upper mean tolerance limit for these fish is 32.5 deg C for a period of 72 hours, and they cannot withstand temperatures below 8 deg C. Results from thermal tests show a mean upper avoidance temperature of 31.1 deg C (range: 30.6-31.7 deg C). In comparing these results with the reported temperature range of 10.0 to 34.1 deg C as found in nature, there is good agreement with the low temperature. An apparent discrepency exists with the high temperature of 34.1 deg C reported from field survey data and the laboratory test result of 32.5 deg C. The difference may be attributed to variation between surface and bottom temperatures. Only surface temperature was reported. Predators: No specific information was found on natural marine predators. The fish hawk, Pandion haliaetus, may prey upon the puffer, however the only account found describes the unsuccessful attempts by a fish hawk to capture these fish as they would inflate themselves out of the bird's talons. Parasites, diseases, injuries, and abnormalities: Cyclopoid copepods were found to be parasitic to northern puffers collected from the Woods Hole, Massachusetts area. Specimens of the copepods Tucca corpulentus Wilson and Pseudochondracanthus diceraus Wilson were attached to the fins and gills, respectively, of puffers. Copepod collections at the U.S. National Museum were examined and it was reported that catalogue number 79595 labeled P. diceraus collected by Wilson from "Gills, Spheroides maculatus" as misidentified. These are instead T. corpulentus. The following parasitic worms were found in northern puffers from the Beaufort, North Carolina area: Nematoda - Ascaris spp. - A. habena Linton Cestoda - Tetrarhynchus bisulcatus Linton Life History - 3 (DRAFT) - Life History Species puffer, northern Species Id M010500 Date 26 AUG 96 Trematoda - Distomum vibex Linton - Gasterostomum gracilescens Rudolphi NUTRITION AND GROWTH: Feeding: Throughout their range, puffers appear to be opportunistic feeders, preying mainly on available invertebrates. Their powerful jaws enable them to crush and devour anything they capture. When preying on small crabs, northern puffers attempt to paralyze the crustacean by making the first bite in front so as to sever the nerve ganglion. Puffers are known to unite in a group to attack a blue crab. Feeding occurs during daylight hours as puffers are nocturnally inactive. Food: The following is a composite list of dietary constituents: Pelecypods (including scallops, jingle shells, clams, Solemya sp., oysters, mussels, razor clams), gastropods (including Haminoea), barnacles (Balanus sp.), limpets, crabs (including blue, mud), isopods, hermit crabs, shrimp (including Arbacia sp.), sea urchin spines, tests of sea urchins (Moira atropos), annelids, worm tubes, bryzoa, sponges, sea anemones, sea squirts, seaweed, algae, and watermelon seed. GROWTH RATE: The linear growth rate for young-of-the-year fish of approximately 16 mm TL was calculated to be 1.11 mm/day over a term of 45 days. In 1969 the growth rate was 0.93 mm/day over a time period of 60 days. Growth marks on the vertebrae of northern puffer are used for age determination. The saccular otoliths develop growth rings, but they are difficult to interpret. In larger fish the annuli cannot be distinguished. For all age groups, females are larger than males. An analysis of annuli shows most growth takes place during the first growing season from June to October. It is during this period that the significant difference in the lengths obtained by males and females takes place. Thereafter the growth difference between males and females is not significant. Metabolism: Experimental results indicate that the northern puffer is a relatively sluggish fish. Fish activity is generally related to the concentation of various blood constituents such as hemoglobin, erythrocyte number, iron, and sugar. For example, those species with a high hemoglobin concentration can carry on metabolic functions at a higher rate than species with low amounts of hemoglobin. The hemoglobin content in the blood of northern puffer is not considered high and ranges from 5.99 to 12.50 gm/100 ml (mean 9.41 gm/100 ml); the erythrocyte count ranges from 209 to 502/cu mm/10^4 (mean 342/cu mm/10^4). Active pelagic fish have a higher blood iron concentration than fish that are benthic oriented and relatively inactive. The northern puffer iron values rank it as an inactive fish. Concentations range from 17.1 to 28.8 mg/100 cc blood with an average of 21.5 mg/100 cc blood. Blood sugar is also similarly related and in the northern puffer the sugar concentation ranges from 4.5 to 41.3 mg/100 cc blood with an average of 23.1 mg/cc blood. Tests made to determine the effect of insulin in blood sugar showed that puffers did not experience shock with a reduction in blood sugar concentrations whereas more active species, i.e., mackerel and menhaden, shocked when similarly tested. The volume of blood flow in relation to cardiac output usually remains proportional to the overall metabolism of an organism. For puffer, the minimum cardiac output was computed to be 15.5 ml/kg/mm based on an oxygen capacity of 6.75 ml/02/100 Life History - 4 (DRAFT) - Life History Species puffer, northern Species Id M010500 Date 26 AUG 96 ml of blood, and a maximum oxygen consumption of 1.05 ml/kg/min was computed. MIGRATIONS AND LOCAL MOVEMENTS: Northern puffers are sluggish and move by the use of fins rather than by forceful body action. They are known to partially bury themselves in soft bottom by a shoveling motion of their specially developed post-clavicular apparatus. They move through the water column during daylight, but at night become quiescent and lie on the bottom. This difference in diel activity was also observed in captive specimens. Anglers caught more northern puffers during the day. Juveniles may also exhibit a similar diel variation in activity. Surface meter net collections indicate significantly more juvenile tetrodontids collected during the day than at night. SCHOOLING: Young fish are found in large rambling schools. Adults are more solitary. RESPONSE TO STIMULI: Blowfish are capable of inflating themselves for a temporary period. The inflating mechanism consists of the powerful muscles of the first branchiostegal ray, which depress a pad covering the ceratohyals, thus expanding the mouth cavity and drawing in water or air. The elevation of the ceratohyals forces the fluid into the sac, which is a ventral diverticulum of the stomach, partially separated from it by a sphincter-like ring. Fluid is retained in the diverticulum by the strong oesophageal sphincter and by the pylorus. The flap-like breathing valve in the mouth does little or nothing in this connection. The opercular valves prevent leakage during the compression stroke, but the distended state of the sac can be maintained even when they are held open or removed. The fluid in the sac is released by the relaxation of the oesophageal sphincter which allows the fluid to escape from the fish through the oral and opercular openings. The water used in inflation is released in intermittent spurts at first, followed by a stream, and finally declining to a trickle. The inflation capacity can be related to the standard length of the fish or with the formula: (SL x 0.61)^3 x 0.0005236 = cc. Defensive swelling usually occurs with the accompaniment of sounds which are described as long bursts of creaking erk-erks. These sounds are caused mainly by the grinding of the upper and lower jaw plates and to a small degree the swim bladder may aid as an amplifier. Similar sounds are made during feeding and may serve to attract other puffers that are remote from the feeder. Laboratory tests with the use of electric stimulation produced sounds consisting of low dull thumps and usually did not induce inflation of the fish. When puffers are exposed to temperatures approaching their thermal tolerance, they show certain characteristic behavioral changes. Heat shock is exhibited by an increase in both respiratory and general activity along with equilibrium disturbances such as darting, floating, surfacing, tail elevation, constant fin movement, and imbalance. Cold shock is characterized by convulsive spasms, equilibrium loss, and increased respiratory activity. When subjected to gradually colder temperatures, different behavior patterns are displayed. For example, the feeding aim is adversely affected below 12.8 deg C. Puffers will not inflate, even when stimulated, when the temperature is less than 10 deg C. Swimming becomes sluggish and the fish remain near the bottom. when the temperature drops to Life History - 5 (DRAFT) - Life History Species puffer, northern Species Id M010500 Date 26 AUG 96 4.4 deg C they were observed to ascend in a horizontal, upright position. Swimming remained sluggish. The fish will succumb to temperatures of 3.3-4.4 deg C by decreasing all activity and sinking to the bottom. TOXICITY: The family Tetradontidae includes many species that are notably toxic. A type of fish poisoning is commonly known as puffer poisoning. A species which is toxic in one area may not be poisonous in another. The toxicity of these fish is largely influenced by their reproductive cycle. Prior to and during their spawning season they are most poisonous. Many researchers believe that toxic algae may be a component in the production of tetradotoxin. The skin, liver, ovaries, and intestines are generally the most toxic parts of the puffer. The musculature at times may be poisonous. Tetradotoxin cannot be determined by the size or appearance of the fish. Small puffers can contain enough toxin to be lethal. The opison acts mainly on the nerve centers of the victim. Death is the result of suffocation and cardiac paraysis. Cooking the fish cannot destroy the toxin and there is no known antidote for puffer poisoning. POPULATION: Size composition: The maximum size for puffers is 35.6 cm (14 inches) but most are less than 25.4 cm (10 inches) in length. A comparison of the length to weight relationship between sexes shows males weigh less than females at a given length. The modal weight of females is about 82 g more than males for fish collected off New Jersey. Fish collected from Virginia waters were examined and it was found that about 89 to 99% of the variation in weight is associated with variation in length of pre- and post-spawning puffers of each sex. Puffers of both sexes were heavier after recovery from spawning (late July to November) than fish of comparable length before spawning (April to early July). Covariance tests indicated that this difference in weight was not significant in females but was in males at the 5% level. A large increase in muscle and liver tissue occurred during the growing season but was not quantified. By November fish appeared more robust and had larger livers than in April. A comparison of the length to weight data on fish collected from both Virginia and New Jersey shows that for a corresponding length, Virginia puffers are heavier even though the feeding habits are similar in the two areas. Results of comparisons of the weights of various body organs, i.e., the heart, liver, spleen, and gut to the entire body weight of the fish did not indicate any sex-related differences in organ-body weight ratios. Population in the community and the ecosystem: A wide variety of other fishes cohabit the same area as northern puffer. However, the interrelationships of the species in the community and ecosystem are not known. The results of surveys deal with the relative abundance in which puffers occur. There is no information available on the cyclic fluctuations of puffer populations. Documented evidence on changes in environmental factors and their effect on the population is scarce. The mass puffer kill that occurred off the New Jersey coast in mid-May 1969 may have been attributed to a combination of nocturnal behavior and an influx of cold water. Bottom temperatures ranged from 4 to 9 deg C in the New York Bight during that time period *181*. Life History - 6 (DRAFT) - Life History Species puffer, northern Species Id M010500 Date 26 AUG 96 LIFE HISTORY CODES - Breeding/Spawning Season: May Breeding/Spawning Season: June Breeding/Spawning Season: July Breeding/Spawning Season: August Breeding/Spawning Season: September Breeding/Spawning Season: October Spawning Site: Sand Gestation/Incubation Period: 5-7 days Average Number of Offspring/Reproductive Effort: Grea Parental Care of Young: No care given young Periodicity: Active in day REFERENCES FOR LIFE HISTORY- 181 Life History - 7
                           (DRAFT) - Management Practices
                              Species puffer, northern
                                 Species Id M010500
                                   Date 26 AUG 96



MANAGEMENT PRACTICES

COMMENTS ON MANAGEMENT PRACTICES - Northern puffers are not fished for specifically on a commercial basis, and are incidental to the main catch. The recreational fishery consists of hook and line fishing from both shore and boats. As puffers readily take bait, they are considered a nuisance by some anglers seeking other fish species. They are fished during the warmer months in the northern part of their range, and probably year-round in the southern part of their range. No information was found concerning protection and management of the species *181*. Management Practices - 1
                                   (DRAFT) - References
                                 Species puffer, northern
                                    Species Id M010500
                                      Date 26 AUG 96



     

References

181* Sibunka, J.D. and A.L. Pacheco. 1981. Biological and fisheries data on northern puffer, Sphoeroides maulatus (Bloch and Schneider). Technical Series Report No. 26. National Marine Fisheries Service/NOAA. Highlands, N.J. References - 1