The venomous toadfish Thalassophryne nattereri (niquim or miquim): report of 43 injuries provoked in fishermen of Salinópolis (Pará State) and Aracaju (Sergipe State), Brazil

O peixe-sapo venenoso Thalassophryne nattereri (niquim ou miquim): relato de 43 acidentes provocados em pescadores de Salinópolis (Pará) e Aracaju (Sergipe), Brasil

CASE REPORT

The venomous toadfish Thalassophryne nattereri (niquim or miquim): report of 43 injuries provoked in fishermen of Salinópolis (Pará State) and Aracaju (Sergipe State), Brazil

O peixe-sapo venenoso Thalassophryne nattereri (niquim ou miquim): relato de 43 acidentes provocados em pescadores de Salinópolis (Pará) e Aracaju (Sergipe), Brasil

Vidal Haddad Junior^{I, II}; Pedro Pereira Oliveira Pardal^III; João Luiz Costa Cardoso^{II, IV}; Itamar Alves Martins^IV

^IFaculdade de Medicina, Universidade Estadual Paulista, Botucatu, SP, Brasil

^IIHospital Vital Brazil, Instituto Butantan, São Paulo, SP, Brasil

^IIIFaculdade de Medicina, Universidade Federal do Pará, Pará, Brasil

^IVFaculdade de Biologia, Universidade de Taubaté, SP, Brasil

^{Correspondence}

SUMMARY

Fishes of family Batrachoididae are responsible for great number of injuries in fishermen in North and Northeast regions of Brazil. The genus Thalassophryne presents various venomous species of fishes found in the Brazilian coast, T. nattereri being the most common of them. The venom is ejected through two hollow spines on the dorsal fin and two on pre-opercular regions, which present a venomous gland in the base and can be erected or depressed by the fish. The manifestations of the envenoming were intense local pain, edema and erythema in 43 patients observed in Salinópolis (Pará State) and Aracaju (Sergipe State). There were no systemic manifestations, but necrosis was detected in eight and bacterial infection in ten injured fishermen. The circumstances of the contacts and therapeutic aspects are discussed. Envenoming by the genus Thalassophryne is important and frequent and should be considered of moderate severity grade, since there are not the excruciating pain or the massive local necrosis provoked by scorpionfishes (Scorpaena) or stingrays injuries nor the systemic manifestations that are the most important marker of severe envenoming.

Keywords: Venomous fishes; Toadfishes; Thalassophryne nattereri; Venomous marine animals.

RESUMO

Os peixes da família Batrachoididae causam um grande número de acidentes em pescadores das regiões Norte e Nordeste do Brasil. O gênero Thalassophryne apresenta várias espécies no Brasil e a espécie Thalassophryne nattereri é a mais comum, todas apresentando veneno. O veneno é inoculado por duas espículas ocas na nadadeira dorsal e duas nas regiões pré-operculares, ligadas a uma glândula de veneno na base. Os envenenamentos causaram dor intensa, edema e eritema iniciais em 43 pescadores observados em Salinópolis (Pará) e Aracaju (Sergipe). Em todos os casos, não ocorreram fenômenos sistêmicos dignos de nota, mas ocorreu necrose local em oito pacientes e infecção bacteriana em dez. As circunstâncias dos acidentes são comentadas, assim como aspectos terapêuticos. Nossa conclusão foi que o envenenamento por Thalassophryne é importante e freqüente e deve ser considerado de média gravidade, em função de não haverem fenômenos sistêmicos, como observado nos acidentes por peixes-escorpião (Scorpaena) ou arraias marinhas e fluviais.

INTRODUCTION

Injuries provoked by toadfishes are common in the North and Northeast regions of Brazil¹. The first reports and studies of the venom actions and clinic aspects of the envenoming caused by Brazilian toadfishes (Thalassophryne nattereri and Thalassophryne punctatus) were published by FRÓES, in 1932¹ and 1933^2,3.

There are various species of fishes of the family Batrachoididae in the Brazilian coast, but Thalassophryne nattereri is the most common (Fig. 1). The Brazilian toadfishes have small to medium length (about 15 cm) and they are numerous in estuarine areas. Their venomous apparatus presents two dorsal fin and two gills cover hollow needlelike spines with venomous glands in the base (Fig. 2). The fish stays motionless in the sandy or muddy bottoms and the venom is injected in the flesh of the victim through the spines when the gland is pressured by stepping of a fishermen or bather. Experimental studies about the venom report the development of one potential antiserum to neutralize the nociceptive, edematogenic and necrotic effects of the venom^5,6,7.

CASES DESCRIPTION

The authors observed 26 patients injured by niquins (Thalassophryne nattereri) in Salinópolis (Pará State) in a fifteen-day period and 17 injured in the Vaza-Barris region (Aracaju, Sergipe State) in a ten-day period. The fishes collected by the victims were classified by an author (IAM) and were donated to the Ichthyology Collection of the "Universidade de Taubaté" (São Paulo State).

All the patients were male fishermen, aging from 7-64 years old. About 80% of the fishermen were injured stepping on the fish in shallow waters and 20% while removing the fishes from the fish-nets. The main manifestations were intense local pain, erythema and edema (100% of the victims – Fig. 3). Follow-up by one week was possible in 28 patients (65%). Four of these patients (14%) developed local blisters, nine (30%) presented local skin necrosis (Fig. 4) and 10 (36%) presented local bacterial infection that was treated with cefalexin 2 gr/day for 10 days. Skin necrosis and clinic bacterial infection in the same patient were noted in three fishermen, but the importance of venom, infection or both in the necrosis is not clear for us.

Systemic manifestations were absent in the series, but there were agitation and malaise, probably caused by the pain. The immersion of the wounded extremity (the foot in 80% and the hand in 20% of the patients) in hot water decreased the pain, but it had no effect in the initial edema and erythema.

COMMENTS

Injuries provoked by toadfishes of the specie T. nattereri were reported in Brazil seventy years ago^2,3,4. These fishes present the most advanced venomous apparatus of all the venomous fishes of the world, with hollow spines and glands in the base. They are very common in estuarine areas and provoke injuries with frequency, when they are stepped by fishermen and bathers.

In our series, envenoming should be classified as moderate based on the signs and symptoms presented. The pain was intense and the erythema and edema were present in the wound, but there were no systemic manifestations like dyspnea, cardiac arrhythmias, systemic bleeding nor the excruciating pain observed in injuries by scorpionfishes⁴ or the massive and frequent areas of cutaneous necrosis caused by stingrays envenoming, especially freshwater stingrays⁴. However, the pain, inflammation and occasional necrosis caused severe incapacity of the victim and these facts and the frequency of the injuries in North and Northeast regions justify further clinic and experimental studies on toadfish envenoming.

Received: 2 April 2003

Accepted: 25 June 2003

• 1. FRÓES, H.P. - Sur un poisson toxiphore brésilien: "le niquim" Thalassophryne maculosa Rev. sud. amer. Med. Chirurg., 3: 871-878, 1932.
• 2. FRÓES, H.P. - Peixes toxíforos do Brasil. Bahia méd., 4: 69-75, 1933.
• 3. FRÓES, H.P. - Studies on venomous fishes of tropical countries. J. trop. Med. Hyg., 36: 134-135, 1933.
• 4. HADDAD Jr., V. - Atlas de animais aquáticos perigosos do Brasil: guia médico de identificação e tratamento. São Paulo, Roca, 2000. p. 81-88.
• 5. LIMA, L.A.F. & FERREIRA, M.L. - Estudos clínico e experimental sobre o envenenamento causado pelo peixe Thalassophryne nattereri (niquim). An. bras. Derm., 75: 435-443, 2000.
• 6. LOPES-FERREIRA, M.; BARBARO, K.; CARDOSO, D.F.; MOURA-DA-SILVA, A.M. & MOTA, I. - Thalassophryne nattereri fish venom: biological and biochemical characterization and neutralization of its toxic activities. Toxicon, 36: 405-410, 1998.
• 7. LOPES-FERREIRA, M. - Thalassophryne nattereri (niquim): do veneno à terapia. São Paulo, 2000. (Tese de doutorado - Instituto de Ciências Biomédicas/Universidade de São Paulo).

Publication Dates

• Publication in this collection
  17 Sept 2003
• Date of issue
  Aug 2003

History

• Accepted
  25 June 2003
• Received
  02 Apr 2003