Rediscovery of bonnethead shark Sphyrna tiburo after more than two decades of non-record on central coast of Brazil jose ’ amorim reis-filho 1,2 , cla ’ udio l.s. sampaio 3 , luciana leite 4 , gabriel s.a. oliveira 2 , miguel loiola 1,2,5 and jose ’ de anchieta c.c. nunes 1,2 1 ECUS, Institute of Education, Science and Socio-Environmental Utility, Rio Vermelho, 41940-250, Salvador, BA, Brazil, 2 Laborato ´rio de Ecologia Bento ˆnica and PPG em Ecologia e Biomonitoramento, Instituto de Biologia, Universidade Federal da Bahia—UFBA, Rua Bara ˜o de Geremoabo, Ondina, 40170 115, Salvador, BA, Brazil, 3 Universidade Federal de Alagoas, Unidade de Ensino Penedo, Avenida Beira Rio, Centro Histo ´rico, 57200 000, Penedo, AL, Brazil, 4 Harrison House, Homerton College, Hills Road, Cambridge University, Cambridge, United Kingdom, 5 Laborato ´rio de Estudos de Recifes de Corais e Mudanc ¸as Globais, IGEO–UFBA, Rua Bara ˜o de Jeremoabo, Ondina, 40170 115, Salvador, BA, Brazil We report the sighting of bonnethead shark Sphyrna tiburo juveniles ,60 cm total length (L T ) after more than two decades of apparent absence in Todos os Santos Bay (Brazilian eastern coast). A total of 8 specimens were collected on the Paraguac ¸u estuary during a Long Term Fish Monitoring Programme. The L T , total body mass and stomach contents are reported. Relevance for nursery areas to this threatened species is also discussed. Keywords: threatened shark, estuary, Todos os Santos Bay, Brazil, nursery areas Submitted 13 February 2014; accepted 2 April 2014 INTRODUCTION Sphyrnids sharks have become an important group in conserva- tion researches and recreational and commercial fishing (Brill et al., 2008; Mandelman & Skomal, 2008). Sharks have been often captured as by-catch in commercial fisheries not always being considered as primary target, but still suffering high harvest rates and showing declining populations (Mandelman et al., 2008; Frick et al., 2009; Walsh et al., 2009). This pattern of population decline has received urgent attention over the past decade, since studies have indicated rapid and widespread declines as a consequence of direct and indirect effects of fishing activities (Dulvy et al., 2008; Ferretti et al., 2010). In this context, marine biologists and governmental man- agers have debated the existence of patterns of decline for dif- ferent species, the apparent community changes, and whether sharks play unique and fundamental roles in such patterns or not (Myers et al., 2007; Heithaus et al., 2008). Additionally, this debate highlights that Fish Monitoring Programmes carried out by governmental agencies can be an inefficient approach to elucidate trends and occurrences as these pro- grammes ignore the heterogeneity in species’ responses to fishing by aggregating catch data for all species (see Halls et al., 2006; Lorenzen et al., 2006). The bonnethead shark Sphyrna tiburo (Linnaeus, 1758) is one of the smallest species of hammerhead shark with a maximum total length of 1.5 m (Cervigon et al., 1992; Compagno, 2005; Compagno et al., 2005). Among Sphyrna genera, S. tiburo differs from other species by having the pre- branchial head shovel shaped with a broadly rounded anterior margin and electrosensory pores distributed across the width of the head on dorsal and ventral surfaces; other differences include pore density and the width of head when compared to trunk (Kajiura, 2001; Compagno, 2005). It has a wide- ranging geographical distribution across the Atlantic Ocean, inhabiting especially coastal areas of the continental shelf in tropical and warm temperate zones (Compagno et al., 2005). In the south-western Atlantic the species is present on the Brazilian coast, its distribution ranging from the north coast of Amapa ´ State to southern Brazil, where its limit is still not determined, being possibly Santa Catarina State (Godoy, 1987; Compagno et al., 2005)—well known as the southernmost limit of most tropical fish species in the Atlantic Ocean (Barneche et al., 2009). Despite this apparent occurrence, S. tiburo is considered to be extinct or extremely rare on the south-western Brazilian coast (Bornatowski et al., 2009). According to the IUCN Red List of Threatened Species (IUC, 2013), S. tiburo is globally classified as ‘least concern’ due to its high population growth rates when compared to other sharks, making this species less susceptible to extinction (Corte ´s, 2008). In northern Brazil, S. tiburo represented about 10% of the total elasmobranch catches in the 1980s (Lessa, 1986) being frequently captured as by-catch in gill nets, bottom trawl and block nets (Fre ´dou & Asano-Filho, 2006). In the early 2000s, in south-east Brazil, S. tiburo was considered to be regionally extinct, vulnerable or collapsed (Gadig et al., 2002; Motta et al., 2005; Motta, 2006; Bressan et al., 2009). Thus we report the rediscovery of the bonnethead shark S. tiburo on the Brazilian eastern coast, more specifically in Corresponding author: J.A. Reis-Filho Email: amorim_agua@yahoo.com.br 1 Marine Biodiversity Records, page 1 of 7. # Marine Biological Association of the United Kingdom, 2014 doi:10.1017/S1755267214000487; Vol. 7; e44; 2014 Published online