Testes morphology and reproductive aspects of male Brazilian codling (Urophycis brasiliensis Kaup...

J[ Appl[ Ichthyol[ 05 "1999#\ 023Ð024 Received] December 0\ 0887Þ 1999 Blackwell Wissenschafts!Verlag\ Berlin Accepted] February 5\ 0888ISSN 9064Ð7548

This is a companion paper to Acun½a\ A[^ Viana\ F[^ Vizziano\ D[^ Danulat\ E[] Reproductive cycle of female Brazilian codling\Urophycis brasiliensis "Kaup 0747#\ caught o} the Uruguayan coast[ Journal of Applied Ichthyolo`y\ 05"1#\ pp 37Ð44[

Short Communication

Testes morphology and reproductive aspects of male Brazilian codling "Urophycisbrasiliensis Kaup 0747#

By F[ Viana\ A[ Acun½a\ N[ Berois and E[ Danulat

Seccio�n Oceano`ra_a\ Facultad de Ciencias\ I`ua� 3114\ 00399 Montevideo\ Uru`uay

Summary

The very _rst data on male {bro�tola| Urophycis brasiliensis"Phycidae\ Gadiformes# are presented here[ Apart from thedescription of the macroscopic and microscopic morphology ofthe testes\ preliminary results are given with respect to repro!ductive aspects of the males caught o} the Uruguayan coast[

In Uruguay\ the gadiforms are represented by two species ofcommercial interest] the hake Merluccius hubbsi being theprincipal _shing resource\ and Brazilian codling Urophycisbrasiliensis locally called {bro�tola|\ one of the most importantcoastal resources of the artisanal _sheries "Anon[ 0880#[ Althoughthe latter species is common in coastal waters of the Atlanticbetween 12> and 39> S\ little information is available[ Between0882 and 0885\ a comprehensive 2!year study dedicated to aspectsof the biology and _sheries of U[ brasiliensis in Uruguayan waterswas carried out[ A manuscript on reproductive aspects of thefemales has been submitted for publication "Acun½a et al[ 1999#[ Inthe present paper\ _rst results on the gonadal morphology of themales are given[ Vladikov "0861# compared the testes of di}erentgadids\ including another species of the genus\ Urophycis chuss[However\ to date no related information has been published onU[ brasiliensis\ likely also due to the fact that males are much lessfrequent than females in nearshore captures[

Samples "N � 47# of shallow captures "³19 m# of {bro�tola|were obtained from artisanal _shermen in the two most impor!tant _shing ports in Uruguay] Piria�polis "23> S 44> W# and LaPaloma "23> S 43> W# "Acun½a et al[ 1999#[ Additional samples"N � 10# of deeper captures "up to 42 m# were obtained onspring and summer cruises of the research vessel {Aldebara�n|"INAPE^ National Fisheries Institute#[

In the _eld\ total length and weight were recorded to thenearest cm and g\ respectively "Table 0#[ Fish size ranged from12Ð59 cm and 002Ð1399 g\ respectively[ Following dissection\the _sh were sexed\ and in most cases "N � 58# testes wereweighed to the nearest 9[90 g[ Gonads were extracted and _xedin 09) bu}ered formalin until the histological analysis[ Inthe laboratory\ ten testes were cut at di}erent levels "cephalic\medium and caudal# to determine possible longitudinal di}er!ences in the spermatogenesis[ Twenty samples were analyzedhistologically to identify testicular structures and to diagnosethe gonad maturity stage[ Each piece was dehydrated\ embeddedin para.n\ cut to 6mm thickness and _nally stained with Mayer|shaematoxilin and eosin "Ganter and Jolle�s 0869#[ The gonado!

U[S[ Copyright Clearance Center Code Statement] 9064Ð7548:1999:0592Ð9023,04[99:9

somatic index "GSI# was calculated and compared in bothshallow and deeper capture areas in spring and summer[

Macroscopically\ the male gonad of U[ brasiliensis "Fig[ 0# iseasily distinguishable from the ovaries\ allowing a rapid andunmistakable sex identi_cation in the _eld[ Two testes of dissimilarlength are found below the swimbladder[ They can be seen as twowhitish ribbons presenting a smooth surface and several irregularlobes\ similar to U[ chuss testes "Vladykov 0861#[ Their macro!scopic structure corresponds to type IIIa of the classi_cation pre!sented by Vladykov "0861#[ The lobes are larger in the cephalicportion than in the caudal portion\ and fused to the vas deferensthat longitudinally crosses both testes[ In the caudal region\ theyare fused and open to the urogenital ori_ce[

Histologically\ the {bro�tola| testes correspond to the lobulartype described by Billard "0875# with anastomosing tubules"Fig[ 1#[ All along the testes\ similar spermatogenesis wasobserved[ They can also be de_ned as the unrestricted spermato!gonial type of Grier "0870#\ the most common testes type in _shspecies\ where it is possible to _nd spermatogenesis along theentire length of the tubule[ In the caudal region\ an area isfound without spermatogenetic epithelium but with a greaterconcentration of spermatozoa ready to be evacuated[

Males were signi_cantly less represented in the captures thanwere females "P³ 9[94#\ making up only 2) of the total catch"N � 1499#[ Wenner "0872# and Gallardo!Cabello "0875#showed sex segregation in two other species of the same family"Phycis phycis\ P[ blennoides#[ At the same time\ Eklund andTargett "0889# observed di}erent sex proportions in capturesof U[ re`ia "spotted hake# and U[ chuss "red hake#[ However\this e}ect was explained by selectivity of the capturing gear[

Mean total length of males showed signi_cant di}erences"P ³ 9[94# between shallow "23[7 cm# and deeper "18[2 cm# cap!tures[ The segregation by size might be explained by intrae!speci_c competition "Sedberry and Musick 0867# which\ incombination with the selectivity of the _sheries\ would result ina higher proportion of females in the samples[

Captures revealed a signi_cant size di}erence between males"this paper# and females "Acun½a et al[ 1999#\ reaching meanlengths of 22[5 cm and 33[9 cm\ respectively[ The size of allindividuals exceeds the one proposed as the mean size ofmaturity "12 cm# for U[ brasiliensis males caught o} SouthernBrazil "M[ Haimovici\ pers[ comm[#[

Due to the scarce representation of the males in the samples\it was not possible to study the spatial and temporal variation

Testes morphology and reproductive aspects of male Brazilian codling 024

Table 0Total length "cm# and weight "g# of male U[ brasiliensis captured by theartisanal _shery and from RV {Aldebara�n|[ Mean values 2 standarddeviation are presented

Length "cm# Weight "g#Sample origin N Mean SD Mean N SD

Artisanal _shery 47 23[2 3[9 47 245 039RV {Aldebara�n| 10 18[3 2[1 10 140 001

Fig[ 0[ Macroscopic view of the U[ brasiliensis testes\ corresponding toan individual of 20 cm[ Note the dissimilar length and irregular lobesin the two testes[ Numbers indicate centimeters

of testicular maturation[ At any rate\ mainly stages of mid! andlate recrudescence\ partially spent and one post!spawn wereidenti_ed[ At a mean length of 21[5 cm\ signs of testes recrud!escence "Table 1# were observed[

Testicular GSI ranged between 9[93 and 1[79[ In deeper cap!tures\ mean GSI was signi_cantly higher\ indicating a greatermaturation activity during spring and summer[ This may sug!gest that reproductive events of U[ brasiliensis take place outsidethe artisanal _shing areas\ as proposed for females of the speciesby Vizziano et al[ "0882# and Acun½a et al[ "1999#[

Acknowledgements

Funding was provided by the Comisio�n Sectorial de Investi!gacio�n Cient(�_ca "CSIC# and PEDECIBA!CONICYT ofUruguay[ Also\ the authors wish to thank the _shermen AlfredoHargain\ and Pelusa and Atilio Batista and personnel of theInstituto Nacional de Pesca "INAPE# for making available thestudy material[

References

Acun½a\ A[^ Viana\ F[^ Vizziano\ D[^ Danulat\ E[\ "1999#] Reproductivecycle of female Brazilian codling\ Urophycis brasiliensis "Kaup

Fig[ 1[ Histological section of U[ brasiliensis testes[ Z � spermatozoa^CC � spermatocyte cyst^ TC � spermatid cyst^ ZC � spermatozoacyst^ L � lumen of a spermatogenic tubule[ Scale bar � 099 mm

Table 1Mean total length "cm# of U[ brasiliensis males for each maturity stagediagnosed histologically "mid:late recrudescence^ partially spent andpost!spawn# 2 standard deviation

Length "cm#Maturity stages N Mean SD

Mid:late recrudescence 01 21[5 3[4Partially spent 6 28[2 2[3Post!spawn 0 37[6 −

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Author|s address] Federico Viana\ Seccio�n Oceanogra_a\ Facultad deCiencias\ Igua� 0314\ 00399 Montevideo\ Uruguay[e!mail] fvianaÝfcien[edu[uy