• •

The Resources Agency of California Department of Fish and Game

SURVIVAL POTENTIAL OF PIRANHA IN SOUTHERN CALIFORNIA WATERS'

JAMES A. ST. AMANT Region 5, Inland Fisheries

SUIXARY

This report is a summarization of the data available on piranha in relation to its potential for establishment in southern California. Included are the results of a literature search and information from ?ersonal interviews and correspondence with biologists in this country and South /merica. Observations of piranha in aquaria are recorded, although no biological experirentation was conducted.

In general, there has been very little scientific research completed on piranha; even the taxonomy is in a state of confusion. The exact range of the piranha is unknown. Piranha can be identified from similar related species, although dental examination may be necessary tdth small fish.

Little information is available on life history; although successful methods have been developed for spawning in aquaria. 7:oese species are known to be prolific and provide parental care resulting in high survival of young.

Sufficient evidence exists to demonstrate piranha pose a threat to humans and fish and wildlife.

An analysis of available data indicates piranha could survive and become establishe in some waters in southern California. Guidelines for further study are presented.

• ■•••■ 1/ — Submitted September, 1967. Inland Fisheries Administrative Report No. 67-12.

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INTRODUCTION

The Department of Fish and Game is concerned with the harmful effects to our fish and wildlife and water-orientated recreation should piranhas become established in any of our waters. There is a danger that the present widespread importation of piranhas will result in their release into open waters where a reproducing population could be established.

The question has arisen as to whether or not piranha could survive in our waters. This paper attempts to answer this question by presenting a compendium of the available relevant data on piranha in relation to its survival and establishment potential in southern California. A biological study has not been attempted; however, aquarium observations are included.

ACNIIMLEDGMNTS

William M. Richardson and Richard Flint reviewed and provided advice on presentati of the data. Marschall Stevens and Robert Carr assisted in the literature search. I am also grateful to the people in this country and South America who responded to my inquiries regarding piranha.

CLASSIFICATION

Family

Piranhas belong to the family Characidae, members of which are commonly called characins. The family contains about l,.O known species and is divided into 9 subfamilies of which the piranha is listed under Serrasalminae.

Characins are distributed throughout South America, excluding the southernmost part, and the Pacific slope of Chile. Their distribution continues north through Central America as far as Texas and New Mexico. A few genera also are found in Central Africa.

Genera

There is some confusion as to the genera of the true piranhas. Gery (1963) said, "In spite of abundant literature on the 'Piranhas', genus Serrasalmus Lacepede, rich principally in secondary details about their bloody behavior, nothing is known of their biology and, still more strangely, very little of their taxonomy." Norman (1929) considered only 2 genera, Pygopristis, containing a single species, and Serrasalmus containing at least 17 species, of which only 4 are considered true piranhas. Stoye (1949) pentioned that 6 genera comprising about 30 species are known. Fouler (1950) listed 3 genera: Serrasalmus, Pygopristus, and Pygocentrus, with over 40 species.

Piranhas are sometimes referred to as pirambeba, caribe, carabito, pria, chupita, rodoleisa, palomita, piraya, umati, pana, arri, hatte, chitao, huma, arai, and peroi.

The natural distribution of piranhas has not been defined, but is generally considered south and east of the Maritime Andes of Venezuela through the Orinoco and Amazons to northeastern Argentina (Figure 1). -4-

Description

C-crlerally, piranhas have a deep, compressed body shape (Figure 2). However, 1 species described by Fowler (1950), C. elongatus, has a trout-like elongated body form.

The body is scaled (scales usually very small) with no scales on the head. The lowermost scales of the abdomen overlap and form a serrated edge (V-shape or keel- like).

An adipose fin is always present. All of the piranhas I have observed had a short based adipose with the exception of 1 unidentified specimen on display at Harineland which had a long-based adipose.

Piranhas have a long-based dorsal fin (14 or more rays). Gosline (1951) states they have 16 or more rays. The anal fin has from 29 to 37 rays. A superobital bone is present. The lower jaw usually extends beyond the upper jaw and the mouth is generally oblique (Figure 2).

Piranhas are further characterized by having a single row of trilobed (or simple) large, sharp teeth (Serrasalmus), or 5 or more pointed denticulate teeth with wavy margins (yzepristus) on both jaws. Gobline (1951) described the teeth as close set and of the shearing type with 12 in the upper jaw and usually 14 in the lower.

Other closely related members of the Char.:xidae f.=ily that may be confused with piranhas have 2 rows of teeth On the premaxillary. Workers familiar , with piranha can usually distinguish them from these similar characins: Colossoma, Mylossoma, MIleul, Metynnis, and Piaractus without examining the teeth. When identifying very small fish, dental examination may be necessary. Gosline (1951) furnished further difference in that ColosSoma and Hylossoma lack the predorsal spine present in Serrasalmus.

Anonymous (1965) provided the following distinguishing characteristics of similar species; "Genera Colocsoma and Piaractus: No predorsal spine; the short adipose fin of the adults of some species of 13 aractus may have rays. Genus Mylossoma: No ptedorsal spine; adipose never with rays so far as known; very deep bodied with exceptionally long-based anal fin, the base of which may be more than one- third the body length; the belly serrations are the most highly developed in the subfamily. Genus 1 j1eus Dorsal fin base rather long, dorsal fin with 20 or more dorsal rays and with at least two-thirds of the abdomen with well- developed serrations. Adipose never with rays. Genus Pletynnis: Easily distinguished from all other serrasalmines by the long, low, unrayed adipose fin, the base of which is longer than ligh and one-half or more as long as the dorsal fin base. Fish belonging to this genus are commonly imported and cold under the name of 'silver dollars' or ' Roosevelt 1 ."

Coloration of piranhas varies: for example, Innes (1966) states, "... from lemon trimmings on silver, to some with bright red bellies. S. snilonleura is characterized by a black edge on the tail fin." -5-

o Orinoco RITISH GUIANA NAM RENCH GUIANA S z ..0 x.. Amazon system m ; ------4-4,--

15 CO River PE

■ •••••". ••••••■... CHIL

AY

KN Area of distribution.

Scale of Miles 3Q0 600 900 1200

Figure 1. Approximate range of Piranhas - South America. Figure 2. Specimen of a piranha killed by timbo powder. Commercial Fisheries Review, Vol. 25, No. 3. -7-

Eigenmann (1915) prepared a key to the genera, and a key, with synomymies, to te species of Serrasalmus. Norman (1929) presented a revision of the species including Cerrasalmus. However, Moe (1964) mentions, from personal communications with Meyers referring to work conducted by Leviton of the California AcaCepy of Sciences, that, "Norman's revision cannot be accepted as to species." (1951) has provided a key to the genera of the subfamily Serracalminae.

LIFE HISTORY

Although the piranha is infamous the world over, actually little is known about its habits in the wild. It appears to prefer quiet water in deep pools and does not occur in rapids. Eigenmann and Allen (1942) note, "They are most frequently taken in the clearer waters of the quieter, backwater bayous and their inlets or outlets, and less abundantly in the swifter and muddier waters." Cutright (1940) mentions they prefer the placid waters above and below falls. Van Humboldt in 1830, quoted by Cutright, believed the piranha to be r bottom fish, "... but the experience of others led them to bel:ove it has no preference either for deep water or for shallow. It has been seen at all hours of the day both inshore and midstream."

Menezes (1960) mentions piranha spawn during all mnntho of the year, apparently with no special ecological requirements. It appears the eggs of some species are laid on submerged plants and roots just beneath the surface near the bank of a stream (Brown and Lidstone, 1870). Hart, quoted by Eigenmann and Allen (1942), ... describes the nests of Pygocentrus as depressions fanned out in sand during flood stages, where the eggs were laid in a ball of two or three inches diameter." Brown and Lidstone describe the eggs as white and approximately one-eighth of an inch in diameter and with a hard shell. They further mention "The young were not much larger than the eggs and were covered with a gelatinous substance that had the effect of causing them to stick together in the water." I assume they are referring to eggs and sac fry.

At least three persons have been successful in spawning piranhas in captivity. They are: William P. Braker (1960, 1963) at the John G. Shedd Aquarium, Chicago, S. allopleura and S. n er; Kyle Swegles (Anonymous, 1963) at the Rainbow Aquarium Chicago; and Emanuel Ledecky (1966) at the Cincinnati Aquarium, S. 2piloE1.eura. Ledecky observed both parents preparing a nest site and the male guarding and aerating the eggs. Five spawnings occurred at intervals of 7 to 24 days. He informed me (personal correspondence, 1966) "The eggs were never counted,but well over a thousand is a conservative estimate." Ledeckyla illustration of the spawning act is shown in Figure 3. Noe (1964) reports Swegles stated his piranhas exhibited careful parental guarding of the eggs and the fish spawned once every two weeks releasing up to 5,000 adhesive eggs. Braker (1960) meations, "..• after spawning, the males chased away the females and guarded the eggs."

These observations demonstrate that ailopleura and S. nig.er are prolific and exhibit parental care; consequently survival should be high.

Braker (1963) says young S. soilopleura reach a length of 1.75 inches in 3.5 months under aquarium conditions. -9-

Figure 3. Ledeckyls drawing of one of the piranha spawnings at the Cincinnati Zoo. Tropical Fish Hobbyist. -11-

Tropical fish dealers have informed me that small imported piranha can reach I ches or more within 6 months or sooner by excessive feeding of live food. nt least some of the pirrnhas are capable of extended longevity. Two S. niger held at the Shedd Aquarium lived more than 20 years. These fish reached a length of over 18 inches and weighed 5.5 pounds.

A 4-inch S. ailonleurahel&in an aquarium for 4 months without food survived with no apparent ill effects;-,whichAndicates this species is capable of surviving long periods of famine.

Figure 2 illustrates the size of piranha obtained by Fontenele (1963) in his rotenone treatment work to eradicate there fish in waters. .of the northeastern region of Brazil.

SURVIVAL TEMPERATURES

Could piranha survive California winter water temperatures? Carl Hubbs (personal communications, 1965) said, "Inasmuch cc several species are found south of Paraguay in the La Plata River, there in a very high possibility if not probability some species -would survive in the lowland streams of southern California." Myers (1965) stated, "I am of the opinion that piranhas could survive in California's fresh waters comparable in temperature range to the southernmost temperature localities where they are found in South America." In personal correspondence

between Alex Calhoun and N. P. Gody in 1955, the latter 0mentions there are piranhas that live in waters which have winter temperatures of 46 F. to 57° F.

Axelrod (1965) stated he has collected piranha under ice.

John Prescott informed me of a S. rpilopleura held in the Marineland laboratory that has survived and stayed in good condition in an aquarium without heat throughout the winter. The temperature in the aquarium was in the 60's° F. At the time I enatened the piranha, June 22, 1965, the water temperature was 68° F. Jerry Goldsmith told me that in 1962 this same piranha was held in an outdoor pond through the winter months.

Braker (personal correspondence) found in a preliminary investigation that 3- ° month old S. 22.i1op1eura became inactive at 55 F. and died if held at this temperature for several days. But acclimatization time was only one week. He further stated, "These fish could possibly establish breeding populations in some of our.states.such as Florida, Hawaii, and possibly California."

Prcfessor C. J. D. Brown (personal correspondence, 1965) comments speaking of Paraguay, "Piranhas are present in practically all waters of that country, and this in spite of the variable conditions." He continues, mentioning he found records where, "Lake Ypacarai has in the past had a thin skim of ice on it as have some of the oxbows of the Rio Febicuary in the south central part of the country. No one has reported fish losses from these drops in water temperatures and piranhas apparently persisted in these waters in spite of them." Steinberg (personal correspondence to Robert Carr, 1966) related, "... last summer I was in0 the headwaters of the Jaura River, a tributary of the ParagUay River at about 15 south of the equator. The lower Jaura is said to have piranha, and we had temperatures very close to freezing during the invasion of a cold front from the south." Herold (quoted from Calhoun, 1965) has stated that piranha might survive in such waters as are found in San Diego County. De Magalhoes (personal correspondence, 1966) referring to piranhas in the Sao Paulo area tells me, "... they survive occasional frosts when air temperature drops below 0° C. (32° F.). This happens, of course, in bigger masses of water where radiation is slow enough to keep the 0 0 water at temperatures of 7° C. (44.6 ° F.) or 8° C. (46.4 F.) even when air temperature is -2° C.(28.4° F.) or -3 C (26.6° F.)." Temperatures of sections of the Colorado River and several of the low elevation reservoirs in San Diego County drop only to the low 50's° F. (Tables A-1 to A-11). A review of the water temperatures of 10 reservoirs in southern California reveals that temperatures seldom0 drop below 50° F. (Tables A-1 to A-10). Water temperatures in these waters are 70 F. or above from 1 to 7 months of the year. Therefore, considering how prolific these fish are, even the least temperature tolerant of piranhas from the warmer waters of South America could survive at least a portion of the year, multiply, and present at least a short term danger to the fish in these waters. They would also have an opportunity to become established through natural selection.

Axelrod (personal correspondence, 1966) stated, "There are certainly coldwater varieties of piranhas. I know of several other species which are identical physically in all respects, except that the northern race must have warm water and the southern race must have cold water. This is especially true of some Corydoras."

Even the more thermophylic species of piranha could probably survive in streams that receive water from hot wells in couthorn California. One such stream is a tributary of the Salton Sea, Imperial Courn:y, where the water originates at a hot mineral cpa (St. Amant, 1966).

SURVIVAL ADAPTATIONS

The adaptation of fishes to conditions other than those to which they are indigenous is not unusual. Isaev (1963) relates on the increase in acclimatization of fish in the Soviet Union. Seventy-four species have been introduced including fish from France, England, China, and Czechoslovakia. Hichling (1962), in speaking of native carp and imported mirror carp in the hot lowlands of Java, states, "... the European carp did adapt themselves to temperatures considerably high?r than those experienced in Europe."

Threadfin shad, Dorosoma .1..netenense, believed to be unable to survive in water temperatures under 55 F. are now found in most, if not all, of the waters directly or indirectly connected to the Colorado River,which was the0 location of the original introduction. They are row known to survive in 34 F. water and spawn in 58° F. water (Rawstron, 1934).

Probably the most dramatic illustration of a successful, but unwise, introduction of a nonnative species into California waters is the carp, CIT2inup camio. Five carp imported from Holstein, Germany, in 1872 soon became many and are now abundant in the lowland waters of the Central Valley, most of the reservoirs in southern California, the Colorado River, many drainages in the coastal areas, and the east slope of the Sierra Nevada. Kimsey and Fisk (1964) wrote, "The carp is the biggest 'pest' of the nongame fish. It destroys aquatic plants utilized by waterfowl, roils the water causing silt-sensitive fish to disappear, and competes directly with game fish for food and space." -13-

Mosquitofish, Gambusia affinis, native to the Gulf states, have been successfully introduced into waters throughout most of the United States. Rawley (1963) describes how out of thousands of mosquitofish introduced into the waters of Utah to control mocquitoo, 12 survived the winter temperatures to provide the brood- stock of the now well-established mosquitofinh in Utah. Necquitofich ecare established in California in 1923.

Another member of the family Poeciliidae, the sailfin molly, Poccilia (Mollienesie latipinna, native to South and Central America, is established and extremely abundant in the Salton Sea and its tributaries. The Salton Sea ranges in water temperatures from 50 to 97° F. (Walker, 1961).

Tilapia morsambica, another thermophilic species native to Africa, is now established in a tributary of the Salton Sea (St. Amant, 1966).

Don Smith, Arizona Regional Game and Fish Manager, informed me (oral communication, 1966) that T. mossambica is abundant in drainage canals adjacent to the Colorado River, southwest of Yuma.

Tsukuda (1961) has acclimated guppies, Lebistes reticulatus, to 64.4° F.

I have collected rainwater fish, Lucania parva, (native to the eastern United States) in Irvine Lake, Orange County. This specimen is believed to have been accidentally introduced through fish transplants from the Pecos River, New Mexico (Hubbs and Miller, 1965), and has become established despite the presence of large populations of predator fishes cnch as largemouth bass, Micropterus salmoides, and black crappie, Pomoxis nigromaculatus.

Moe (1964) lists 5 freshwater fishes, considered tropical species, that are now established in Florida waters: 'Tilejaa heudeloti, Plecostomns a., Astronotus ocellatus, Hemichormis al.,' and Delonesox belizanus. Luis Rn Rivas, Curator of Fishes, University of Miami (personal correspondence, 1966), mentions that Cichla ocellaris, indigenous to tropical South America, has been fntroduCed in the Miami area.

One Characin found in Texas and New Mexico, the Mexican banded tetra, Antyanax fasciatus mexicanus, has been recorded as being sold as a bait fish for use in the Colorado River by Evans and Douglas (1950). Hubbs (personal correspondence, 1966, Follett's letter to Hubbs) informed me of evidence that these fish are reproducing in the Colorado River; W. I. Follett of the California Academy of Sciences believes they are now established in California. Denson (1955) described the danger involved in the possible introduction of this species into Tennessee waters.

Moe (1964) concluded, referring to Florida waters, "Under favorable conditions, a mild winter, accidentally liberated piranhas ray be able to survive And reproduce and then natural selection would favor those indtviduals with the lowest temperatur tolerances."

BENEFICIAL USES OF PIIIANDAS

MClane (1965) regards piranha as of limited angling value. "They can be caught on any strip or cut bait and occasionally are taken on artificial lures. A wire leader is essential Piranhas have some food value and are consumed by Indians of the Orinoco and Amazon. The teeth are sometimes used to fashion arrow- heads for small game and birds." Myers (1949) mentioned that Amazonian and -14-

Guiana Indians use the jaws of piranhas as a combination knife and scissors.

Tbe only use piranhas would have in this country would be as specimens exhibited in aquaria.

DANGER TO HUMANE

The piranha is considered extremely aggressive and will attack all animals regardless of size, including humans. Ditmars (1931) states, "... it would make a ferocious wildcat seem tame by comparison." Theodore Roosevelt (1914) called it, "... the most ferocious fish in the world." Schultz and Stern (1948) mention, ... attacks out of cheer bloodlust. This savage little killer, usually 8 to 12 inches long, is vicious out of all proportion to its size and unlike sharks, which ordinarily attack only animals smaller than themselves, seems to be utterly fearless." Myers (1949) calls the piranha the most dangerous fish in the Amazon and perhaps in the world.

Calhoun in 1961 related the following from correspondence with Professor M. P. Godoy of Sao Paulo, On March 4, 1961, Godoy wrote and told me about a chemical treatment in Ceara State, Brazil, as follows:

"And during this operation against piranhas, six workers were wounded by Serrasalmus, and twelve persons were mutilated during this same operation when taking piranhas under timbe action! And one of these twelve persons was emasculated, with almost fw.al resultL."

Fontenele (1963) states, "In the State of Ceara alone, its two largest hydrographi( basins are infested with piranhas: Jaguaribe River (28,957.5 square miles) and Acorou River (15,354.7 square miles). In those areas, great losses are inflicted upon cattle and men, particularly those who fish for a living. Small scars, but also mutilations and even loss of lives are traceable to the awesome piranhas." A photograph of a piranha inflicted wound is included in Figure 4.

Guenther (1931) writes, "The piranhas and not the crocodiles are the real danger in the Brazilian rivers."

Cutright (1940) referring to Simone Bolivar, "... on May 28, 1819, was leading his army across the Venezuelan Illanos to New Granda, some of his men were severely wounded as they swam a stream intercepting their route."

Dr. J. Alex Munro (personal correspondence, 1965) informed me that a friend of his by the name of Barber, who war vacationing in the vicinity of Santa Cruz, Bolivia, was attacked by piranhas while swimming in a river described as slow and deep. Munro states, "He was so suddenly attacked by a school of these fish that he died as a result."

A recent report of piranha attacking hurans is mentioned by Associated Press (1966) "Man-eating piranha fish devoured 21 guerrillas in the Arauca River in southwest Venezuela, the newspaper La Religion reported today ... the victims were among 23 leftist rebels on a raft who were surprised by a national guard patrol near the village of Alto Arauca. The guerrillas jumped into the river to escape but 21 were eaten by the carnivorous fish ..." -15-

Figure 4. The wound inflicted on a 16-year-old boy attacked by a piranha in "Riacho dos Cavalos" Dam, Paraiba State. The photo was taken 5 minutes after accident. Commercial Fisheries Review, Vol. 25,No. 3. Cutright (1940) cites numerous incidents from scientific and popular literature of piranha attacks on humans. There are numerous accounts of the vicious behavior of the piranha which in some cases is no doubt exaggerated. However, too many authorities have witnessed this behavior to disregard all of the accounts as fictitious.

There are reports of piranhas present in large numbers among bathers who are unmolested; according to Schultz (1964), "... naked children and adults romp and play among schools of the fearsome piranhas." But he further states, "Naturally the natives of the Brazilian jungles know where and when they can swim, and avoid swimming unnecessarily far out in Piranha-infested waters." Moe (1964) tells of an employee of the Florida Board of Conservation, "... dove among piranhas in the waters of Surinam and reports that the individuals and small groups encountered seemed timid and avoided him. The natives indicated to him that the waters were only dangerous at certain times."

The reasons for the difference in the behavior of piranha at different times and places is not obvious. Fish behavior, of course, varies with their psychological and physiological state. Temperature no doubt ploys an important role, the lower the tuner temperature the less aggressive is the piranha. Aggressiveness also varies among the different species, for example, Myers (1949( referring to S. brandtii comments, "I have bathed in Lagoa Santa, where this species is common, and natives say it is harmless. He continues, "S. onilonleuna ... is probably not a dangerous form, although personally I would not like to trust it too far." Concerning C. elonpatus he says, "It is very doubtful that it ever attacks men ... "Speaking of S. rhombeus he states, "... F7, certainly of very little danger to man."

Braga (1959) confirms Myers feelings on S. rhombeus following his study of this species' feeding habits (2,222 fish examined) he states, "Contrary to the common idea, the pirambeba rarely attacks man or terrestrial animals."

Sick (1960) mentioned that he found three different species of piranhas who were not equally pugnacious. He adds, "The most dangerous period was the end of the dry season, when a large number of piraya found themselves constricted in a small area." Schultz (personal correspondence, 1965) reports that he was left alone while swimming among piranha, unless he had a cut or wouad, and sometimes was • not bothered even then. However, he mentions that the species found in the San Francisco River are said to be dangerous and attack men.

Although piranha will bite through a net when captured, small Serracalmus spn. (10 tested individually) would not attack my hand when placed near them. However, when attempting to capture a 2 1/2-inch S. clailopleura with my Ex.7e hand I was bitten. The piranha bit into my second finger, right hand, below the first joint and would not release its hold until forcefully shaken loose. The wound consisted of a half circle tear, 1/4-inch in diameter and'about 1/16-inch deep. It bled profusely.

Mr. Dwight Norris, a student at Pepperdine College, Los Angeles, was severely bitten on the left thumb by a Serrasalmus approximately 6-inches long that had jumped a net while being transferred from one aquarium to another. This wound required 5 stitches to close, and also bled profusely. 'Anonymous (1935) tells of three bites inflicted on humans by aquarium-held piranhas. Ferry (1952) states, "An erperienced aquarist of the Department of Commerce Aqtarium in Washington, D. C., list the end of a finger handling an aquarium specimen." A Mrs. Datha Wellman of Huntington Beach, California, received a severe wound when she placed her hand into an aquarium containing her "pet" piranha. The wound required treatment at the Los Alamitos Naval Air Station dispensary.

DANGER TO WILD AND DOMESTIC ANIMALS

In addition to the potential danger to man that piranha exhibit, the danger to wildlife and domestic stock is even greater. The Commercial Fisheries Review (1962) reports, "... for two years Argentina has had a serious problem with piranhas attacking cows at the Parana River Basin. Particularly in the marginal lagoons which abound with piranhas and where the Oxen and cows must drink." Many of the popular books concerning South America mention accounts of wild and domestic animals being attacked ty these fish. Schurz (1961) refers to an instance where a caiman wounded by a jaguar attempted to escape ty returning to the water and was attached Ly a school of piranhas.

Dr. P. Nogueira (personal correspondence, 1965) tells of "a farmer (Fzenda Roseira) who built a small dam and released piranhas in it. There, after some time, it was impossible to breed ducks and geese because the piranhas attacked them." He further states, "In Northern Brazil, and also in the State of Mato Grosso, the piranhas are a vary bad fish, attacking even herds of cattle, when they go inside some waters." Cognac (1963) describes how the vaquero° of South America sacrifice a steer to the piranhas so the herd may safely cross the piranha infested rivers.

Beebee in 1917, according to Cutright (1940), mentions finding fragments of ducks, kingfishers, and kiskedees in piranha stomachs. Braga (194) found that the major food of piranhas consisted of shrimp and fishes: many other animals and small amounts of vegetation were included.

Introduction of nonnative species always includes a certain amount of danger to the native fauna, even when the nonnative species do not pessess ohe piranha's undersirable characteristics. An example of what can result is C000nst.:ated by Nelson's (1965) investigations in the Nananakis River system, Alberta, "Dolly — Varden (Salvelinus malma), brook trout (S. fontinalis.), cutthroat trout (alp) clarki), and rainbow trout (I.. z.airdneri) decreased in abundance, probably due to the introduction of brown trout (alto trutta), longnose suckers (Catostomus catostomus), and white suckers (C. commersoni), +4."

An example of the effect piranha have on a fishery is illustrated hy Fontenele (1963). He compares the fish production of 2 dams in Brazil. 7h. the Acarau Dam, where piranhas were eradicated, the goverment collected $29,465 from fishermen and the weight of fish produced during the period from May, 1960 to May, 1961 was 3,323 metric tons. A larger dam, Estevam Morinho Dam, containing piranha, during the same period produced only $12,860 in fishing licenses and yielded only 1,336 tons of fish.

Dr. Magalhaes (personal correspondence, 1966) advised us to try to obtain special legislation to avoid introduction of piranha. "All the world is paying for senseless, hurried introductions of birds, mammals, fishes, insects, etc. My common sense tells me that you have 997. chances of disaster to the local fauna if 'piranhas' are ever at home in California waters." -19-

Vanzolini, Departamento De Zoologia, Sao Paulo (personal correspondence, 1966), informed me Le considers, in natural conditions, the piranha is not a conservation problem; although, he continues "Of course what we call conservation here is not much. In dams, however, piranha wipes out all the valuable fishes. This is a vajor problem."

I observed A Serracalmus 2.2 inches fork length held in a 40-gallon aquarium with 7 red-ear sunfish averaging 3 inches...for% length destroy all of the red-ear sun- fish within 15 days.

A larger Serrasalmus approximately twice the size destroyed 4 red-ear sunfish within 4 days. The piscivorous behavior of piranha is well known. Marshall (1966) comments, "The best known predators among the characins are the South American piranhas (arrasalmus) and the African tiger-fiches (ilydrocyon), which feed on other fishes." ------

I found that even the so-called milder species of piranha become pugnacious when their environmental conditions change. Two S. brandi placed in a plastic bag containing a large red swordtail, neahophorus helleri, devoured the swordtail with the exception of part of the head and ore eye within a few hours.

Placed in a 5-gallon aquarium overnight, one of the S. brandi killed the other by the following morning. A Serrasalmus cp. approximately 2 inches in length placed in a•40-gallon community tank killed a Colosomma sp. of the came size and tore a large section out of a 4-inch Tilapia mossampica and a 6-inch Mylosoma sp. In addition, the piranha attacked a 5-in.:h soft-shelled turtle, Trionvx spiniferus taking bites out of the upper anterior portion of its shell.

As noted in the experience with S. brandi, piranha will attack their own kind at least under certain conditions. nyers -(1949) believes their schooling behavior ir modified by their fear of each other since they will immediately tear up and devour any injured member of the school. Many of the piranha I have observed in aquaria exhibited old and new wounds obtained from other piranhas. Two of 3 piranhas I placed in a 5-gallon aquarium were killed by the slightly larger 3rd one, even with an abundance of guppies present in the tank. Twelve other Piranhas I have held for observation readily fed on small fish, guppies, and mosquitofish. Ledecky (1966) observed the phenomenon of piranha (24 spilopleura) attacking larger fish while ignoring guppies in the same tank. He suggests the guppies were too insignificant for the piranhas to notice.

COUCLUSICNS

Piranha would definitely be an undesirable addition to our fauna and regulations preventing its introduction are well justified. I concur. with Calhoun's (1965) statement that "Although there is still much data to be aScertained concerning piranha, the possibility of their surviving in Ca3ifornia waters is too dangerous a risk out of all proportion to any benefits that might otherwise be received."

To obtain additional pertinent data would require an elaborate study including:

1. Proper identification and collection of all species of piranha to serve as test fish. -20-

2. An extensive limnoiogicalstudy of the waters in which piranhas are native (particularly the La Plata area).

3. Long term OldriiMUM of 2 years) elaborate studies involving temperature tolerance, acclimatizatioa, and natural selection.

I feel it is possible that piranha could become established in southern California waters either through introduction of species indigenous to the colder waters of South America and/or through natural selection. Areas that are particularly suitable for piranhas are certain tributaries of the Salton Sea, the waters in Imperial County, sections of the Colorado River (see Table A-11), and low elevation reservoirs in San Diego County.

REFEREMEE

Anonymous. 1935. New member initiated in the piranha club. Aquarium, 4 (7) : 14E 1963. Piranhas spawned by famous Chicago hobbyist-dealer. Tropical Fish Hobbyist, 11 (9) : 75-76. 1965. Laws and regulations governing the importation of wild birds, animals and fiches into the State of California. Joint Publ. of the Calif. Dept. of Agriculture and the Calif. Dept. of Fish and Game, 67 p. Associated Press. 1966. Piranha fish devour rebels in Venezuela. Sacramento Bee, January 9, 1966. Axelrod, Herbert R. 1965. Reporter's Partial Transcript No. SOC 10624 Superior Court of the State of California for the County of Los Angeles, p. 15 and 24. Benson, Norman G. 1955. The Mexican bandi?.d tetra. The Tenn. Conservationist, Nashville, Tenn., 21 (2) : 14. Braga, R. Adhemar. 1954. Alimentacao de pirambeba, Eerrasalmus rhombeus (L., 1766) Lacepede, 1803, no acude Lima Campos, Ico, Ceara (Octariophisi, Characidae, Serrasalminae). Rev. Brazil. Biol., 14 (4) : 477-492. 1959. Alimentacao de pirambeba, "Serrasalmus rhombeus" Lacepede 1303, no acude Lima Campos, Ico Ceara. Coletanea de Trabalhoa Tecnicos, Publicacao, no. 164, series 1-C. Braker, William P. 1960. Bill Braker's tank talk. Aquarium, 29 (1) : 6-10. 1963. Bill Braker's tank talk. Aquarium, 32 (10) : 12-14. Brown, C. B., and W. Lidstone, 1373. Fifteen thousand miles on the Amazon and its tributaries. Edward Stanford, London. Calhoun, Alex. 1965. Declaration of Alex Calhoun in opposition to plaintiff's application for preliminary injunction. Supreme Court of the State of California for the County of Los Angeles, May, 1965, p. 3. Cognac, Marcel. 1963. Piranha. Sports Afield, 150 (5) : 46-47 & 88. Commercial Fisheries Review. 1962. Piranhas - a problem in Brasil's inland waters. Comm. Fish. Rev., 24 (1) : 9. Cutright, Paul Russell. 1940. The great naturalists explore South America. The Macmillan Co., New York, 329 p. Ditmars, Raymond. 1931. Strange animals I have krown. Brewer, Warren, Putnam, New York, 375 p. Eigenmann, C. H. 1915. The Serrasalminae and Mylinae. Annals Carnegie Mus., 9 (3) : 226-275. Eigenmann, C. H., and William R. Allen. 1942. Fishes of western South America. Univ. of Kentucky, ed., Lexington, 494 p. Evans, Willis A., and Phillip A. Douglas. 1950. Notes on fishes recently introduced into southern California. Calif. Fish and Game, 36 (4) : 435-436. -21-

Ferry, P. 1952. Little man-eater of the Amazon. Science Digest, 31 : 6-8. Fontenele, Osmar. 1963. Eradication of piranha in inland waters. Comm. Fish. Rev., 25 (3) : 46-50. Fowler, Henry W. 1950. Os peixes de agua doce do Brazil. Arquivos de Zoologia do Ectado de Sao Paulo, 6 : 372-385. Gery, J. 1963. Contributions a letude des poissons characoides. Systenatiryo et evolution de quelques piranhas (gerrasalmus). Vie et Milieu, 27 (14) : Gosline, William A. 1951. Notes on the characid fishes of the subfamily Serrasalminae. Proc. Calif. Acad. Sci., 27 (2) : 17-64. Guenther, Konrad. 1931. A naturalist in Brazil. Houghton Mifflin Co., Boston and New York, 176 p. Hickling, C. F. 1962. Fish culture. Faber and Faber, London, 295 p. Rubin, Carl L., and Robert R. Miller. 1965. Studies of Cyprinodont fishes. XXII. Variation in Lucania parva, its establishment in western United States, and description of a new species from an interior basin in Caohuila, Mexico. Univ. of Mich., Mus. of oo1., Misc. Publ. no. 127 : 104 p. Isaev, A. 1963. Acclimatization of fish in waters of the Soviet Union. Rybevedstov I, 6 (2) : 7-10. Innes, William T. 1966. E....otic aquarium fishes. Aquariums Inc., Maywood, N.J., 19th ed., 592 p. Kimsey, J. Bruce, and Leonard 0. Fish. 1964. Freshwater nongame fishes of California. Calif. Dept. Fish and Game, p. 20-21. Ledecky, Emanuel. 1966. Spawning piranhas. Tropical Fish Hobbyist, 14 (5) : 5-14 Marshall, N. B. 1966. The life of fisher. The World Natural History, The World Publ. Co., Cleveland and New York, 402 p. McClane, A. J. 1965. McClane's standard fishing encyclopedia and international angling guide. Holt, Rinehart, and Winston, New York, 1057 p. Menezes, R. S. 1960. Contribuicao pare o ectudo da pesca no acude Lima Campos. Bol. Dept. Nac. Obras contra Seras, 22 (9) : 1-110. Moe, Martin A., Jr. 1964. Survival potential of piranhas in Florida. Quar. Jour. Florida Acad. Sci., 27 (3) : 196-210. Myers, George E. 1949. The Amazon and its fishes. Part 5. A monograph of the piranha. Aquarium Jour., 20 (2) : 52-61, and 20 (3) : 76-85. 1965. Declaration of George Myers in opposition to plaintiff's application for preliminary injunction. Supreme Court of the State of California for the County of Lon Angeles. Nelson, J. S. 1965. Effects of fish introductions and hydroelectric development on fishes in the Xananashis River system, Alberta. Jour. Fish, Res. Bd. Canada, 22 (3) : 721-753. Norman, J. R. 1929. The South American characid fishes of the subfamily Serracalminae, with a revision of the genus Serrasalmus Lacepede. Proc. Zool. Soc., London, para. 1923, 52 : 781-329. Rawley, Edwin V. 1963. 12 who dared. Utah Fish and Game. Roosevelt, Theodore. 1914. Through the rrazilian wilderness. Charles Scribner's Sons, New York, 409 p. Rawstron, R. R. 1964. Spawning of threadfin shad, Dorosoma petenenpe, at low water temperatures. Calif. Fish and Game, 50 (1) : 58. Schultz, Leonard P. 1964. Piranhas - fact and fiction. Tropical Fish Hobbyist, 32 p. Schultz, Leonard P., and Edith M. Stern. 1948. The ways of fiches. D. Van Nostrand Co., New York, 264 p. -22- Schurz, Lytle W. 1961. Brazil the infinite country. E. P. Dutton and Co., Inc., New York, 346 p. Et. Amant, James A. 1966. Addition of 'Mania morsambica Peters to the California fauna. Calif. Fish and Game, 52 (1) : 54-55. sick, Helmut. 1960. Tukani. Erickson-Taplinger Co., Inc., New York, 240 p. Stoye, Frederick H. 1949. The fishes of the family Characidae. Part VII. Aquarium Jour., 20 (7) : 177-181 & 190. Tsukuda, Hiroko. 1961. Temperature acclimatization on different organization level in fishes. Jour. Biol. Osaka City Univ., 12 : 15-45. Walker, Boyd W. 1961. The ecology of the Salton Sea, California, in relation to the sportfishery. Calif. Dept. Fish and Game, Fish Bull., (113) : 23-24. APPENDIX -24-

TABLE A-1

Barrett Lake, San Diego County 1/ Surface Water Temperatures ,2p63— Elevation - 1,617 feet—

Month Maximum Minimum Average

January 52 45 47.3

February 58 52 56.0

March 61 55 58.1

April 67 60 62.6

May 77 65 70.0

June '77 70 72.2

July 82 73 75.3 August 81 76 76.6

September 80 73 75.1

October 75 64 68.4

November 67 54 59.0

December 56 45 48.5

1/ — Data from Utilities Department, City of Eau Diego, California. 2/ — Dams within jurisdiction of the State of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus Appendix. -25-

TABLE A-2

Sutherland Lake, San Diego County / Surface Water Temperatures ,21962—' Elevation - 2,074 feet"'

Month Maximum Minimum Average

aomm.•■■•■.. ■••■•• •■•■••■•■■■•■■••■■,■■■■•••■•• •■•••.•■■■••••wiewslo■ January 52 48 49.2

February 55 50 53.3

March 60 52 54.4

April 72 GO 67.3

May 75 61 69.4

June 80 70 75.3

July 80 77 78.8

August Cl 79 30.2

September 61 74 77.6

October 74 65 69.7

November 66 55 60.6

December 55 52 54.1

•••■■•••••••• 1/ — Data from Utilities Department, City of San Diego, California. 2/ • - — DLIMO within jurisdiction of the State of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus Appendix. 26-

TABLE A-3

San Vicente Lake, San Diego County / Surface Water Temperature9 7 1964— Elevation - 659 feet-:'

Month Maximum Minimum Average

January 50 54 55.7

February 57 54 54.8

March 62 54 56.5

April 68 59 62.7

May 74 51 67.2

June 79 70 73.6

July 82 75 78.4

August 82 77 79.6

Leptember 80 74 75.8

October 78 69 73.4

November 71 60 64.7

December 61 56 57.7

1/ — Data from Utilities Dt_partment, City cf Can Diego, California. 2/ — Dams within jurisdiction of the State of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus Appendix. -27-

TABLE A-4

Puddingstone Lake, Los Lngeles County ,2 Surface Water Temperature / 1964;.' Elevation - 982 feet='

Month Maximum Minimum Average

January 53 50 51.0 February 54 50 51.5 March 60 52 55.3

April 67 58 62.2 May 71 58 65.3 June 74 65 70.2 July 79 72 76.9 August 80 74 78.3 September 74 71 72.4 October 73 66 69.7 November 67 54 59.4 December 56 51 53.1

1/ — Data from the Los Angeles County Parks and Recreation Department, 2/ — Dams within jurisdiction of the 'tate of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus 4pendix. TABLE A-5

Cachuma Lake, Santa Barbara County / Surface Water Temperature21 1965— Elevation - 766 feet=

Month Manimum Minimum Average

•••■■■•••■

January 59 53 55

February 59 54 56

March 65 54 58

April 75 55 62

May 72 60 66

June 75 65 69

July 80 68 74

August 78 70 74

September 75 69 71

October 71 65 68

Novembek 71 65 68

December 61 49 54

••■•••••• NIIIM•011.•■■•■ 1/ — Data from records of Cachuma Project Water Treatment, Santa Barbara. 2/ — Dars within jurisdication of the State of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus Appendix. TABLE A-6

Ramer Lake, Imperial County Surface Water Temperature, 1p4 1 (Maximum) and 1956 (Minimum)- 2/ Elevation Approximately - 160 feet—

Month Maxinum Minimum Average — — July 98 92 95.6 August 9C 76 87.2

September 92 75 83.5

October 87 66 80.4

April 74 70 71.3

May 78 69 73.6

June 85 73 80.2

July 90 72 82.7.

August 98 84 90.7

September 95 80 87.1

October 85 75 78.8

—1/ Data from personal records of Ray Knight, Department of Fish and Game. 21 Levee blueprint for Ramer Lake, 1950, Department of Fish and Game. -ao-

TABLE A-7

Mathews Lake, Riverside County 1 Surface Water Temperatures,2p65- Elevation - 1,404 feet

Month Ma:cimum Minimum Average

January 54 50 52.0

February 52 50 51.0

March 58 50 54.0

April 64 55 59.5

May 67 64 65.5

June 70 67 68.5

July 76 70 73.0

August 80 76 78.0

September 78 72 75.0

October 77 64 70.5

November 65 61 63.0

December 61 56 58.5

.L/ — Data from Metropolitan Water District, Mathews Lake office. 2/ Dams within jurisdiction of the State of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus Appendix. -31-

TABTE A-8

Henshaw Lake, San Diego Countyli Surface Water Temperatures,21965— Elevation - 2,740 feet./

Month Maximum Minimum Average

January 51 49 50.0

February 51 48 50.2

March 52

April 61 52 56.5

May 63 -- --

June 62 61 61.5 July 75 74 74.5 August -- .... --

September 68 65 66.5

October 66 60 62.0

November 59 55 .57:0

December 50 -- --

....•■•••■.•11.1■ ■•■•■•.••• 1/ — Data from Vista Irrigation District records. 2/ — Dams within jurisdiction of. the .State pf.Oaliforria. St-tts of California,. - Department of Water Resources, r,ulletinlio. 17-65, 1965, ..04 p. plus Appendix. -32-

TABLE A-9

Morena Lake, San Diego County 1/1 Surface Water Temperatures ,21962- Elevation - 3,049 feet—

Month Maximum Minimum Average

January 48 36 43.3

February 52 42 48.2

March 58 45 49.8

April 64 57 61.8

May 68 62 64.5

June '14 65 69.5

July 76 72 74.4

August 77 72 75.1

September .••

October 68 59 61.7

November 60 48 54.8

December 50 41 47.5

1/ — Data from Utilities Department, City of San Diego, California. 2/ — Dams within jvrisdiction of the State of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus Appendix. -33-

TABLE A-10

Lower Otay Lake, San Diego County / Surface Water Temperature2/ 1964— Elevation - 492 feet-1

Month Maxlmum Minimum Average

January 55 51 52.5

February 57 52 54.6

March 64 55 59.0

April 69 61 65.2

May 74 64 68.9

June 76 68 72.7

July 81 76 78.4

August' 81 76 78.8

September 80 75 77.0

October 79 69 74.7

November 72 57 63.8

December 61 55 58.0

Data from Utilities Department, City of San Diego, California. 2.1 Dams within jurisdiction of the State of California. State of California, Department of Water Resources, Bulletin No. 17-65, 1965, 104 p. plus Appendix. -34-

TABLE A-11 Average Minimum Surface Water Temperatures for Three Locations on thilColorado River 1959-1963—

Below Below Cibola Month Parker Dam Palo Verde Dam Bridge area

Cctober 67 71 72 November 63 60 62

December 54 56 54

January 50 52 51

February 52 54 53

March 57 58 59

1/ — Data collected by the U. S. Geological Survey.