scholarly journals Size, sex and maturity of the squid Lolliguncula diomedeae (Cephalopoda: Loliginidae) in the Gulf of Tehuantepec, México.

2015 ◽  
Vol 7 (1) ◽  
pp. 79-87
Author(s):  
María del Carmen Alejo-Plata ◽  
José Luis Gómez-Márquez ◽  
Jorge Eduardo Herrera-Galindo

There is practically no information on the biology of Lolliguncula (Loliolopsis) diomedeae. We analyzed specimens caught in four shrimp fishing trips in the Gulf of Tehuantepec in 1999-2001, 2004 and 2006.Sexual maturity and gonadosomatic index (GSI) were used as indicators of reproductive activity. A total of 1 200 individuals were captured, 89% female. Females ranged from 35 to 97mm in mantle length (LDM),with a mode at 80mm and weights 2 to 30,9g; males 20,7 to 65mm LDM with a mode at 35-40mm and weights from 0,4 to 12g. Differences in the LDM and the PT between males and females were significant (KS, p<0,05). The sex ratio was 8:1 H:M (p <0,05). The weight-length relationship type is potential for both sexes, with a negative allometric growth.83% of mature females had high IGS values, in contrast to less than 20% of mature males. The size at first maturity (L50) indicates that males (42,7mm LDM) mature when shorter than females (74,5mm LDM). Maturity, IGS and oceanographic features of the Gulf of Tehuantepec indicate that L. diomedeae spawn there.

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Tiago Magalhães da Silva Freitas ◽  
◽  
Vitor Hudson da Consolação Almeida ◽  
Luciano Fogaça de Assis Montag ◽  
Nelson Ferreira Fontoura ◽  
...  

ABSTRACT Relationship between length and weight (LWR) is used to describe aspects concerning the life cycle of fish, but does not considers possible changes during the lifetime mainly due to the sexual maturation. Thus, this study aims to identify the size at first maturity of Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) and infer if the reproductive engagement could change growth pattern, concerning the LWR. Estimates of the size at first maturity (L 50 ) were made by visual identification of gonadal development and through the gonadosomatic index (G SI ). L 50 was estimated as 12.5 cm for males and 13.0 cm for females when applied visual identification of gonads development. L 50 estimates increased to 13.05 cm for males and 13.7 cm for females when estimated from G SI values. LWR was adjusted by using a regular power function and through the polyphasic growth model, with proportionality and allometric coefficients changing in a two phases. The results indicate differences in the growth pattern concerning males and females, as well as polyphasic growth. The change in the growth pattern of the polyphasic LWR was estimated at 11.42 cm for males and 12.53 cm for females, suggesting that changes in the growth pattern can sign-out the attainment maturity in this catfish.


2010 ◽  
Vol 8 (4) ◽  
pp. 835-840 ◽  
Author(s):  
Nelson F. Fontoura ◽  
Anamélia S. Jesus ◽  
Gabriel G. Larre ◽  
Juliana R. Porto

A weight/length relationship was established for Astyanax jacuhiensis (Cope, 1894) (n = 370) and Cheirodon ibicuhiensis Eigenmann, 1915 (n = 701), from samples taken monthly in Fortaleza Lagoon, Cidreira, Rio Grande do Sul, from December 1991 through November 1992. Both species showed a polyphasic allometric growth pattern, each stanza described by an independent power equation controlled by a switch function. For C. ibicuhiensis, this change in the growth pattern occurred at 2.948 cm standard length (SL), close to published sizes for the attainment of female maturity. The change in the growth pattern of A. jacuhiensis (SL = 3.481 cm) was below the predicted size at first maturity, and merits further investigation. Although not conclusive, our data suggest that a complex growth pattern is frequent in nature, and perhaps is not usually identified because trends are obscured by natural variability. Despite the increased complexity resulting from the application of a more-complex equation, the identification of a change in the growth pattern could indicate important aspects of fish biology, including the attainment of sexual maturity.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Fábio Mineo Suzuki ◽  
Diego Azevedo Zoccal Garcia ◽  
Mário Luís Orsi

To study the reproductive dynamics of the mandi-beiçudo, Iheringichthys labrosus, in the Capivara Reservoir, Paranapanema River, Parana, Brazil, specimens were captured trimonthly from March 2001 to July 2004 at four sampling sites. The sex ratio showed a predominance of females in most of months sampled and the larger length classes. The majority of the individuals captured showed a standard length between 16 and 22 cm, with a maximal length of 27.5 cm. The size at first maturity was estimated to be 18.1 and 19.7 cm for females and males, respectively. Analysis of the temporal variation of the gonadosomatic index (GSI) and frequency of occurrence of gonadal maturation stages of males and females for the months sampled showed that I. labrosus reproduces during the whole year, with peak reproduction in November and December. There was a positive correlation between the mean values of GSI and variation in rainfall values, suggesting that this abiotic factor can influence the reproduction of this species. The mean absolute fecundity was 67274.5  16562.5 oocytes, and the mean relative fecundity was 350.6  186.3 oocytes per gram of total weight.


2015 ◽  
Vol 75 (3 suppl 1) ◽  
pp. 158-167 ◽  
Author(s):  
TMS. Freitas ◽  
BS. Prudente ◽  
VA. Oliveira ◽  
MNC. Oliveira ◽  
EG. Prata ◽  
...  

Abstract This study investigates the influence of the flood pulse on the reproductive biology of the auchenipterids Tocantisia piresi (Miranda Ribeiro, 1920) and Auchenipterus nuchalis (Spix & Agassiz, 1829) from the middle Xingu River in the Brazilian state of Pará. The specimens were collected every three months between April, 2012, and January, 2014, covering four distinct periods (flood, ebb, dry, and filling). The sex ratio, size at first maturity, gonadosomatic index, and condition factor were analysed in the two species, and evaluated in the context of the different hydrological periods. A total of 897 specimens of T. piresi were collected, of which 467 were female, and 430 males, and 383 A. nuchalis (286 females and 97 males). In T. piresi, the sex ratio was biased only in the filling and ebb periods, whereas in A. nuchalis, it departed significantly from the expected ratio of 1:1 in all periods, with a predominance of females. The female T. piresi mature at a smaller size than the males, with the opposite of the pattern being recorded in A. nuchalis. In T. piresi, the breeding peak was observed during the low water periods, whereas in A. nuchalis, the peak was recorded in the flood periods. Male and female T. piresi presented similar positively allometric growth rates, whereas in A. nuchalis, growth was negatively allometric, but rates were different between genders. A higher condition factor was recorded in the females of both species during the ebb period. Overall, the results of this study reveals distinct flood pulse effects on the reproductive parameters of the two auchenipterid species studied; for A. nuchalis the spawning seems to happen at the flood period and for T. piresi at the dry season of the middle Xingu River.


2020 ◽  
Vol 68 (2) ◽  
Author(s):  
Francimário S. Feitosa ◽  
Carla Ferreira Rezende

Introduction: Hydroelectric dams have several impacts on migratory fish, such as decreasing their abundance, local extinctions, and changes in the assemblage structure. Objective: To investigate the trophic and reproductive strategies of Leporinus piau upstream and downstream from a hydroelectric dam in the Parnaíba River. Methods: We identified food items and calculated trophic niche breadth in both sites to characterize the feeding strategy. We conducted permutational multivariate analysis of variance (PERMANOVA) to determine differences in diet between sites, followed by a SIMPER analysis in order to show which items were the most dissimilar. To characterize the reproductive strategy, we analyzed weight/length relationship, body condition factor, gonadosomatic index, and size at first maturity. Results: Leporinus piau was classified as an omnivore with a predominantly plant-based diet at both sites. The diet and niche breadth varied between sites. The condition factor differed between sites while size at first maturity differed between sites and sexes. Conclusions: Leporinus piau variations upstream and downstream from a hydroelectric dam in the Parnaíba River are results of differences in life histories traits, as identified in the life history theory, which clarifies the differences on trophic and reproductive strategies.


1998 ◽  
Vol 49 (2) ◽  
pp. 163 ◽  
Author(s):  
P. Appleford ◽  
T. A. Anderson ◽  
G. J. Gooley

The gonadal development, reproductive cycle and growth of Macquarie perch, Macquaria australasica Cuvier, in Lake Dartmouth and selected tributaries of the Murray–Darling River Basin in south-eastern Australia were evaluated. Gonadosomatic index (GSI) and histological analysis were used to determine gonadal development and age and size at first maturity in the resident Lake Dartmouth population. GSI analysis was also used to determine age and size of Macquarie perch at first maturity in the inflowing Mitta Mitta River and other riverine populations within the Goulburn River catchment. Males appeared slightly smaller at first spawning than females at all sites; both sexes were fully mature at four years of age. Differences in size at first maturity were found between the lake and river populations; both males and females of river populations tended to mature at a much smaller size than the fish resident in the lake. Spawning occurred around November. Ovarian and testicular development in this species follows a pattern similar to that of other native Australian percichthyids. The implications for management of recreational fisheries based on minimum size regulations is discussed in relation to site-specific differences in growth rates and size of first maturity of fish.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. N. Sarmiento-Lezcano ◽  
R. Triay-Portella ◽  
A. Guerra-Marrero ◽  
D. Jiménez-Alvarado ◽  
U. Rubio-Rodríguez ◽  
...  

Abstract Notoscopelus resplendens is an abundant myctophid in the region of the Central-Eastern Atlantic. As with a majority of other myctophid species, this species performs vertical migration, playing a key role in the oceanic food web and in carbon sequestration. We examined the reproductive biology of N. resplendens based on 579 specimens caught between 1997 and 2002 off the Canary Islands. We found that the maximum standard length (SL) was lower than the size reported by other authors. The sex ratio was not different from 1:1. The average size at first maturity (L50) was higher in females (60.34 mm SL) than in males (56.61 mm SL). The gonadosomatic index (GSI) at 50% sexual maturity in females was higher than that in males. The reproductive activity was observed from January to April, while from May onwards, the majority of fish caught were in the process of maturation. The macroscopic scale of maturation was validated through the histological analysis of the ovarian development. The batch fecundity was related to the standard length, with an average of 1068.69 ± 369.84 eggs/spawn. These first data obtained for N. resplendens indicated that it is a batch spawner with asynchronous ovarian development.


2016 ◽  
Vol 106 (0) ◽  
Author(s):  
José R. S. Barradas ◽  
Isabel S. Lermen ◽  
Gabriel G. Larré ◽  
Thaís P. Martins ◽  
Nelson F. Fontoura

ABSTRACT A weight-length relationship was established for Corydoras paleatus (Jenyns, 1842) (Siluriformes, Callichthyidae) (n=596) from samples taken in November-December 2009 and March-April 2010, in Pinguela Lagoon (29°46'57"S; 50°11'16"W), Rio Grande do Sul, Brazil. The species showed a polyphasic allometric growth pattern, each stanza described by an independent power equation controlled by a switch function: W = a1Lb1 ∙ (1 + eRsc ∙ (L-SCP))-1 + a2Lb2 ∙ [1 - (1 + eRsc ∙ (L-SCP))-1] ; where W is the expected weight for a specific length L, a1 and a2 are the proportionality coefficients for stanzas 1 and 2, b1 and b2 are the allometric coefficients for stanzas 1 and 2, Rsc is the stanza changing rate for the switch function and SCP is the stanza changing point for the switch function. The stanza changing point was estimated as 5.28 cm, corresponding with the length at first maturity for this species Lmat (5.29 cm). Our data suggest that a complex growth pattern can be in nature, and perhaps not often identified because trends are obscured by natural variability.


2016 ◽  
Vol 8 (1) ◽  
pp. 21
Author(s):  
Selvi Oktaviyani ◽  
Mennofatria Boer ◽  
Yonvitner Yonvitner

<p>Ikan kurisi (<em>Nemipterus japonicus</em>) merupakan salah satu sumber daya ikan ekonomis penting di Perairan Teluk Banten dan banyak didaratkan di Pelabuhan Perikanan Nusantara (PPN) Karangantu, Banten. Intensitas penangkapan yang tinggi akan menyebabkan tangkap lebih (<em>overfishing</em>), sehingga mengancam kelestarian ikan kurisi. Penelitian ini bertujuan untuk mengetahui beberapa aspek biologi ikan kurisi di Perairan Teluk Banten, seperti struktur ukuran panjang, rasio kelamin, hubungan panjang berat, tingkat kematangan gonad, ukuran panjang rata-rata tertangkap (Lc) dan ukuran pertama kali matang gonad (Lm). Informasi yang diperoleh dapat menjadi bahan pertimbangan dalam kegiatan pengelolaan perikanan. Lokasi pengambilan contoh dilakukan di Pelabuhan Perikanan Nusantara (PPN) Karangantu, Banten dari bulan Mei hingga Agustus 2012. Hasil penelitian menunjukkan bahwa ukuran panjang total ikan kurisi<em> </em>berkisar antara 98 dan 211 mm. Perbandingan kelamin jantan dan betina dalam keadaan seimbang dan memiliki pola pertumbuhan allometrik negatif yang menunjukkan pertumbuhan panjang lebih cepat dibandingkan pertumbuhan beratnya. Lebih dari 50% ikan-ikan yang diamati baik jantan maupun betina selama bulan pengamatan belum matang gonad (<em>immature</em>).  Ukuran pertama kali matang gonad adalah 196 mm sedangkan ukuran panjang rata-rata tertangkap adalah 146 mm. Banyaknya ikan yang tertangkap dalam ukuran kecil (kurang dari panjang pertama kali matang gonad) akan mengganggu kelestarian ikan kurisi.</p><p><em><br /></em></p><p><em>Japanese threadfin bream </em>(Nemipterus japonicus<span style="text-decoration: underline;">)</span><em> is one of the most important economical fish resources in the Gulf of Banten and many landed at Archipelago Fishing Port (PPN) of Karangantu. High intensity of fishing activity can cause an overfihing, and threat sustainability of japanese threadfin bream. The research was aimed to determine some biological aspects of japanese threadfin bream in the Gulf of Banten, such as structure of the length, sex ratio, length-weight relationship, gonad maturity stage, the average length of captured (Lc) and the length of first maturity (Lm). It is believed that the collected information can be taken into consideration in the fisheries management activities. The sample was collected at PPN Karangantu, Banten from May to August 2012. The result showed that the length of </em><em>this fish </em><em>ranged between 98 and 211 mm. Ratio of male and female is balance and have negative allometric growth pattern show that the length of growth is more faster than the weight of growth. More than 50% of fish sample both males and females were immature gonads. During observation, length of  first maturity was 196 mm and the average length of captured was 146 mm. </em><em>Many fishes caught was smaller than Lm, It will interfere the sustainability of japanese threadfin bream.</em></p>


1995 ◽  
Vol 46 (4) ◽  
pp. 723 ◽  
Author(s):  
GJ Gooley ◽  
TA Anderson ◽  
P Appleford

The gonadal development of Murray cod, Maccullochella peelii peelii, in Lake Charlegrark, Victoria, and adjacent farm ponds was evaluated. Gonadosomatic index, macroscopic classification and histological analysis were used to determine the age at first maturity and the gonadal development in this introduced population. There is a marked difference between the sexes in the size at first maturity, with females maturing at approximately 6 years of age and 2000 g in weight and males maturing at 3-4 years and 700 g. Gonadosomatic index data indicate that spawning occurs around November. Ovarian development in this species follows a pattern similar to that in a number of other teleosts. Testes have a lobular structure. Macroscopic evaluation of ovaries provided a good indication of the stage of the development of the gonad. However, the presence of spermatozoa throughout the year in the gonads of mature male fish makes the macroscopic evaluation of testicular development less reliable. Three cod, approximately 1% of the population, contained gonads with both ovarian and testicular tissue.


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