Individuals of Zapteryx brevirostris were caught from August 2003 to September 2004 using bottom trawl nets in a bay located in Southern Brazil. Total length ranged from 42.8 to 47.3 cm in males and 44.1 to 52.2 cm in females. Females with early developing embryos were captured in August 2003 and September 2004, suggesting that gestation occurs mainly in the spring. Length- weight relationship of the 45 embryos was alometric, and embryos’ total length did not reach the estimated newborn length. The data suggested that the studied area is used by Z. brevirostris during the gestation period.Ulovljene su jedinke malog ražopsa, Zapteryx brevirostris tijekom razdoblja od kolovoza 2003. do rujna 2004. pomoću pridnenih koćarskih mreža u zaljevu Ubatuba-Enseada, São Francisco do Sul, južni Brazil. 
Ukupna duljina se kretala od 42.8 do 47.3 cm kod mužjaka, te od 44.1 do 52.2 cm kod ženki. Primjerci ženki su sadržavali embrije u ranom razvoju navodeći na zaključak da se gestacija odvija pretežito tijekom proljeća. Maseno-duljinski odnos 45 embrija je alometričan iako ukupna duljina embrija nije dosegla proci- jenjenu duljinu primjeraka novog okota. Podaci upućuju na zaključak da Z. brevirostris nastanjuje istraživano područje tijekom gestacije

Hugo BORNATOWSKI

Matheus OLIVEIRA FREITAS

Vinícius ABILHOA

ABILHOA, Vinícius

BORNATOWSKI, Hugo

OLIVEIRA FREITAS, Matheus

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Some information on reproduction and embryonic development of the lesser guitarfish Zapteryx brevirostris in Southern BrazilVinícius ABILHOA1*, Hugo BORNATOWSKI1 and Matheus OLIVEIRA FREITAS21Fishery and Ichthyologic Group, Museum of Natural Sciences Capão da Imbuia, Pre-fecture of Curitiba, Rua Prof. Benedito Conceição, 407, Curitiba, Paranáe-mail: anequim.bio@gmail.com2Institute VIDAMAR - www.vidamar.org.bre-mail: serranidae@gmail.com*Corresponding author, e-mail: vabilhoa@uol.com.brIndividuals of Zapteryx brevirostris were caught from August 2003 to September 2004 using bottom trawl nets in a bay located in Southern Brazil. Total length ranged from 42.8 to 47.3 cm in males and 44.1 to 52.2 cm in females. Females with early developing embryos were captured in August 2003 and September 2004, suggesting that gestation occurs mainly in the spring. Length-weight relationship of the 45 embryos was alometric, and embryos’ total length did not reach the estimated newborn length. The data suggested that the studied area is used by Z. brevirostris during the gestation period. Key words: Chondrichthyes, Elasmobranchii, Rhinobatidae, reproductive biologyINTRODUCTIONGuitarfishes are distributed mostly along tropical coastal waters of the Atlantic, Indian and Pacific Oceans. Some species can reach moderate to large size, and its members are important components of fishing activities in the Atlantic-Mediterranean region (SECK et al., 2004; CHAVES et al., 2003; VOOREN et al., 2005; COSTA & CHAVES, 2006). Coupled with aggressive com-mercialized fishing and the high capture ratio of pregnant females and adult males, some guitar-fishes are considered to be endangered (LESSA & VOOREN, 2000; SERENA, 2005).  The lesser guitarfish Zapteryx brevirostris (Müller & Henle, 1841) is distributed along the coastal waters from eastern Brazil to northeast-ern Argentina (FIGUEIREDO, 1977). The species is incidentally caught by artisanal fisheries, and because of its low abundance in captures and relatively small size – maximum length of approximately 65 cm (BATISTA, 1987) – the spe-cies has low commercial value (SANTOS et al., 2006). In the coastal zone of Paraná state (South-ern Brazil), Rhinobatos horkelli, R. percellens, and Z. brevirostris were both considered bycatch associated to the shrimp trawl fisheries (CHAVES et al., 2003).ISSN: 0001-5113AADRAYACTA ADRIAT.,48(2):185 - 190, 2007UDC: 597.35 : 591.16 (261.67)186  ACTA ADRIATICA, 48(2): 185 - 190, 2007Despite the wide distribution and abundance in the Brazilian coast, reproductive aspects of Z. brevirostris are poorly known. Some aspects of sexual development (BATISTA, 1987), fecun-dity and embryonic development (BATISTA, 1991) were reported for specimens off an inlet in Rio de Janeiro State, Southeastern Brazil, while population structure was described in the adjacent continental shelf of Paranaguá Bay, Southern Brazil (SANTOS et al., 2006).This paper aims to report biological obser-vations on Z. brevirostris captured in a bay located in Southern Brazil. Resulting data was compared with previous information on lesser guitarfish reproduction along the Brazilian coast as reported by BATISTA (1991).MATERIAL AND METHODSNine trawl operations of five minutes at two knots’ speed were performed monthly from August 2003 to September 2004 using bottom trawl nets (bag with mesh of 3.0 cm between opposite knots) in Ubatuba-Enseada bay in the city of São Francisco do Sul, Southern Brazil (26º 11´S; 48º 29´ W) (Fig. 1). The samples were taken at a depth range of 5 to 12 m along the coastline.Captured specimens were measured (total length), weighed registered by sex. In males, sexual maturity was determined by the condition and length of the specimen’s claspers according to HAZIN et al. (2001). Conversely females, the conditions of ovaries and the morphology of the reproductive tract were used to determine the sexual maturity of the females. Uterine fecundity was determined by counting embryos in pregnant females. Forty-five embryos were removed, measured and weighed after blotting.RESULTS AND DISCUSSIONOf the 21 Zapteryx brevirostris captured, 17 were pregnant females and four were adult males. Mean total length was 44.4 ± 2.0 cm (range, 42.8 – 47.3 cm) in males and 48.4 ± 2.2 cm (range, 44.1 – 52.2 cm) in females. Mean weight was 590.2 ± 245.1 g (range, 410 – 952.2 g) in males and 799.0 ± 132.0 g (range, 580.1 – 1,124.6 g) in females. Registered males were of smaller size than the females, confirming observations of Z. bre-virostris from the adjacent continental shelf of Paranaguá Bay, Southern Brazil (SANTOS et al., 2006), as well as for Z. brevirostris captured in an inlet in Southeastern Brazil (SILVA, 1987). Despite the fact that a small number of individuals were captured, this phenomenon was also reported for other elasmobranch species, such as guitarfishes of the genus Rhinobatos (WENBIN & SHUYUAN, 1993; SECK et al., 2004), stingrays (SNELSON et al., 1988), carcharhinids (SAÏDI et al., 2005), and triakids Fig.1. Study site at Ubatuba-Enseada bay, São Francisco do Sul, Southern Brazil187ABILHOA et al.: Reproduction and embryonic development of the lesser guitarfish Z. brevirostris in Brazil(CAPAPÉ et al., 2005). According to MELLINGER (1989), the fact that males matured in size classes smaller than females, and the adult females were larger and heavier than adult males, is practi-cally a rule for elasmobranch species.BATISTA (1991) observed that the embry-onic development of Z. brevirostris captured in Southeastern Brazil was not synchronized, how-ever part of the population showed a slight syn-chrony from May to August/September. Females with early developing embryos were captured in Ubatuba-Enseada bay in August 2003 and Sep-tember 2004, supporting the conclusion that ges-tation occurs mainly in the in Spring (Table 1).Despite the fact that the total length of pregnant females showed similar patterns reported by BATISTA (1987), observations on reproductive cycle could not be clearly delineated due to an insufficient number of individuals captured. There are only a few published accounts of lesser guitarfish embryonic development along the Brazilian coast. BATISTA (1987) examined 13 embryos of Z. brevirostris captured in an inlet in Southeastern Brazil, reporting embryo length from 11 to 153 mm. The largest embryo was registered in the month of August. From 100 mm total length the embryos display juvenile features and begins the formation of the internal vitelinic sac, which will be full just before birth. GONZALEZ (2004) reported six newborns of a female of Z. brevirostris in captivity in Novem-ber 2002, ranging from 115 to 130 mm. In Uba-tuba-Enseada bay, 45 embryos of seven gravid females were examined, ranging from 29 to 65 mm, and the growth of the aplacental vivipa-rous embryos was alometric (Fig. 2). The fact that all embryos measured did not reached the estimated full-term length (100 mm according to BATISTA, 1987 and 115 according to GONZA-LEZ, 2004), suggests that the parturition probably occurs in late spring or in summer (December). In addition, COSTA & CHAVES (2006) and our per-sonal observations on Z. brevirostris captured at Ipanema beach in 2006 (Paraná state, Southern Month of catch Number Total length (min – max) Uterine contentAugust 2003 2 49.0 – 50.3 cm Early developing embryosSeptember 2003 7 44.1 – 49.3 cm 4 to 9 embryosOctober 2003 3 47.2 – 47.9 cm 6 to 9 embryosSeptember 2004 5 46.0 – 52.2 cm Early developing embryosTable 1. Month of catch, numbers, minimum and maximum total length registered and uterine content of  gravid females of Zapteryx brevirostris caught in Ubatuba-Enseada bay, coastof Santa Catarina, Southern BrazilFig.2. Plot of total length (mm)  vs. weight (g) from 45 embryos of Z. brevirostris captured in  Ubatuba-Enseada bay, Southern Brazil, in August 2003 and September 2004188  ACTA ADRIATICA, 48(2): 185 - 190, 2007Brazil), indicated that full-term embryos in this coastal region occur mainly in the beginning of summer.In our sample, females outnumbered males in agreement with SANTOS et al. (2006), probably as a result of sexual spatial segregation in the reproductive period (LESSA et al., 1986; VILLAVI-CENCIO-GARAYZAR, 1995). The approaching of guitarfish females to the shore could be the result of searching for nursery areas to expel their embryos (LESSA et al., 1986; BATISTA, 1987; BATISTA, 1991; VILLAVICENCIO-GARAYZAR, 1995).CONCLUSIONSAt present, reproductive data on Z. brevi-rostris is insufficient to conclude whether the Ubatuba-Enseada bay is indeed a nursery area. However as several elasmobrach populations’ capture in nearby areas seem to use the South-ern coast of Brazil for the procreation of the reproductive cycle (COSTA & CHAVES, 2006), this hypothesis should not be discarded. In fact, the life cycle of some guitarfish involves nearby estuarine environments and the deeper zones of the shelf itself (LESSA et al., 1986; SANTOS et al., 2006).It is important to note that, although the arti-sanal trawl fisheries and the bycatch associated to it capture incidentally few individual guitar-fish in Southern Brazil, the majority of species captured are pregnant females, indicating that the reproductive cycle is in fact exposed to com-mercial fisheries’ impact. Other observations on Atlantic coast elasmobranches populations reflect the identical problem (SILVA & LESSA, 1991; VOOREN & KLIPPEL, 2005; VOOREN et al., 2005).REFERENCES BATISTA, V.S. 1987. Desenvolvimento sexual de Zapteryx brevirostris (Müller & Henle, 1841), no litoral do Rio de Janeiro, Brasil (Sexual development of Zapteryx brevi-rostris (Müller & Henle, 1841) in the Rio de Janeiro coast, Brazil). Rev. Bras. Biol., 47(3): 301-307.BATISTA, V.S. 1991. Aspectos quantitativos da fecundidade e do desenvolvimento embrionário da raia Zapteryx brevirostris Müller & Henle 1841 (Pisces, Rhinobatidae) da Enseada de Itaipu, Niterói, Rio de Janei-ro (Quantitative aspects of fecundity and embrionary development of Zapteryx bre-virostris Müller & Henle 1841 (Pisces, Rhi-nobatidae) from Itaipu Inlet, Rio de Janeiro, Brazil). Rev. Bras. Biol., 51(3): 495-501.CAPAPÉ, C., J. BEN SOUISSI, H. MEJRI, O. GUELOR-GET & F. HEMIDA. 2005. The reproductive biol-ogy of the school shark, Galeorhinus galeus Linnaeus 1758 (Chondrichthyes: Triakidae), from the Maghreb shore (southern Mediter-ranean). Acta Adriat., 46(2): 109-124.CHAVES, P.T.C., G. COVA-GRANDO & C.C.H. CAL-LUF. 2003. Demersal ichthyofauna in a con-tinental shelf region on the south coast of Brazil exposed to shrimp trawl fisheries. Acta Biol. Paran., 32(1, 2, 3, 4): 69-82.COSTA, L. & P.T.C. CHAVES. 2006. Elasmobrânquios capturados pela pesca artesanal na costa sul do Paraná e norte de Santa Catarina, Brasil (Elasmobranches caught by artisanal fishing in the south coast of Parana State and north coast of Santa Catarina State, Brazil). Biota Neotrop., 6(3): 1-10.FIGUEIREDO, J.L. 1977. Manual de peixes Marinhos do Sudeste do Brasil. I. Introdução. Cações, raias e quimeras (Guide to marine fish from Southeastern Brazil. I. Introduction. Sharks, rays and chimeras). Museu de Zoologia – USP, São Paulo, 104 pp.GONZALEZ, M.M.B. 2004. Nascimento da Raia-viola, Zapteryx brevirostris (Müller & Henle) (Chondrichthyes, Rhinobatidae), em cativeiro (Birth of guitarfish, Zapteryx bre-virostris (Müller & Henle) (Chondrichthyes, Rhinobatidae) in captivity). Rev. Bras. Zool., 21(4): 785-788.HAZIN, F.H.V., A. FISCHER & M.K. BROADHURST. 2001. Aspects of reproductive biology of 189ABILHOA et al.: Reproduction and embryonic development of the lesser guitarfish Z. brevirostris in Brazilthe scalloped hammerhead shark, Sphyrna lewini, off northeastern Brazil. Environ. Biol.  Fish., 61:151-159.LESSA, R.P.T., C.M. VOOREN & J. LAHAYE. 1986. Desenvolvimento e ciclo sexual das fêmeas, migrações e fecundidade da viola Rhino-batos horkelii (Müller & Henle, 1841) do sul do Brasil (Development, females sexual cycle, migration and fecundity of the guitar-fish Rhinobatos horkelii (Müller & Henle, 1841) from southern Brazil). Atlântica, 8: 5-34.LESSA, R. & C.M. VOOREN. 2000. Rhinoba-tos horkelii. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 14 May 2007. MELLINGER, J. 1989. Reproduction et développe-ment des Chondrichthyens (Reproduction and development of Chondrichthyan fishes). Océanis, 15: 283-303.SAÏDI, B., M.N. BRADAÏ, A. BOUAÏN, O. GUÉLOR-GET & C. CAPAPÉ. 2005. Reproductive biology of the sandbar shark, Charcharinus plumbe-us (Chondrichthyes: Carcharinidae) from the Gulf of Gabès (southern Tunisia, Central Mediterranean). Acta Adriat., 46(1): 47-62.SECK, A.A., Y. DIATTA, M. DIOP, O. GUÉLORGET, C. REYNAUD & C. CAPAPÉ. 2004. Observations on the reproductive biology of the blackchin guitarfish, Rhinobatos cemiculus, E. Geof-froy Saint-Hilaire, 1817 (Chondrichthyes, Rhinobatidae) from the coast of Senegal (Eastern Tropical Atlantic). Sci. Gerund., 27: 19-30.SANTOS, C., G. CORTELLETE, K. ARAUJO & H. SPACH. 2006. Estrutura populacional de Zapteryx brevirostris na baía de Paranaguá. (Population structure of Zapteryx breviro-stris in Paranaguá Bay). Acta Biol. Leop., 28(1): 32-37.SERENA, F. 2005. Field identification guide to the sharks and rays of the Mediterranean and Black Sea. FAO, Rome, 97 pp.SILVA, B.V. 1987. Length-weight relationship of the little guitarfish Zapteryx brevirostris (Chondrichthyes: Rhinobatidae), from Itaipu Inlet, Rio de Janeiro, Brazil. Copeia, 3: 787-789.SILVA, T.C. & R. P. LESSA. 1991. Sexual develop-ment of the bonnethead shark Sphyrna tiburo (Linnaeus, 1758) in northern Brazil (Maran-hão). Rev. Bras. Biol., 51(4): 747-754.SNELSON, F.F., S.E. WILLIAMS-HOOPER & T.H. SCHMID. 1988. Reproduction and ecology of the Atlantic Stingray, Dasyatis sabina, in Florida Coastal Lagoons. Copeia, 3: 729-739.VILLAVICENCIO-GARAYZAR, C.J. 1995. Repro-ductive biology of the banded guitarfish, Zapteryx exasperata (Pisces, Rhinobatidae), in Bahia-Almejas, Baja-California-Sur, Mexico. Cienc. Mar., 21(2): 141-153.VOOREN, C.M. & S. KLIPPEL. 2005. Biologia e status de conservação dos cações Squatina gug-genheim, S. occulta e S. argentina (Biology and conservation status of the sharks Squatina guggenheim, S. occulta and S. argentina). In: C.M. Vooren & S. Klippel (Editors). Ações para conservação de tubarões e raias no sul do Brasil, Capítulo 4. (Conservation actions for sharks and rays in southern Brazil, Chapter 4). Igaré, Porto Alegre, pp. 57-82.VOOREN, C.M., R.P. LESSA & S. KLIPPEL. 2005. Bio-logia e status de conservação da viola Rhi-nobatos horkelli (Biology and conservation status of the guitarfish Rhinobatos horkelli). In: C. M. Vooren & S. Klippel (Editors). Ações para conservação de tubarões e raias no sul do Brasil, Capítulo 4. (Conserva-tion actions for sharks and rays in southern Brazil, Chapter 4). Igaré, Porto Alegre, pp. 33-56.WENBIN, Z. & Q. SHUYUAN. 1993. Reproductive biology of the guitarfish, Rhinobatos hynni-cephalus. Environ. Biol. Fish., 38: 81-93.Received: 21 June 2007Accepted: 17 October 2007190  ACTA ADRIATICA, 48(2): 185 - 190, 2007 Saznanja o reprodukciji i razvoju embrija malog ražopsa  Zapteryx bre-virostris u južnom BraziluVinícius ABILHOA1*, Hugo BORNATOWSKI1 i Matheus OLIVEIRA FREITAS21 Ribastveno-ihtiološki odsjek, Prirodoslovni muzej u Capão da Imbuia, Prefektura Curitiba, Rua Prof. Benedito Conceição, 407, Curitiba, Paranáe-mail: anequim.bio@gmail.com2 Institut VIDAMAR - www.vidamar.org.bre-mail: serranidae@gmail.com*Kontakt  adresa, e-mail: vabilhoa@uol.com.brSAŽETAKUlovljene su jedinke malog ražopsa, Zapteryx brevirostris  tijekom razdoblja od kolovoza 2003. do rujna 2004. pomoću  pridnenih koćarskih mreža u zaljevu Ubatuba-Enseada, São Francisco do Sul,  južni Brazil.       Ukupna duljina se kretala od 42.8 do 47.3 cm kod mužjaka, te od 44.1 do 52.2 cm kod ženki. Primjerci ženki su sadržavali embrije u ranom razvoju navodeći na zaključak da se gestacija odvija pretežito tijekom proljeća. Maseno-duljinski odnos 45 embrija je alometričan iako ukupna duljina embrija nije dosegla proci-jenjenu duljinu primjeraka novog okota. Podaci upućuju na zaključak da Z. brevirostris nastanjuje istraživano područje tijekom gestacije. Ključne riječi: Chondrichthyes, hrskavičnjače, Rhinobatidae, reproduktivna biologija 

Saznanja o reprodukciji i razvoju embrija malog ražopsa Zapteryx brevirostris u južnom Brazilu

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