scholarly journals ASPECTS OF REPRODUCTIVE BIOLOGY AND ABUNDANCE OF AFRICAN BONYTONGUE (HETEROTIS NILOTICUS) IN GREAT KWA RIVER, NIGERIA

2020 ◽  
Vol 1 (1) ◽  
pp. 55-65
Author(s):  
N. U. Ikot ◽  
S. B. Ekanem ◽  
V. O. Eyo
Keyword(s):  
Reproductive Biology ◽  
Sustainable Management ◽  
Gonadosomatic Index ◽  
Total Weight ◽  
Hepatosomatic Index ◽  
Gonad Weight ◽  
Female Population ◽  
Total Length ◽  
Egg Diameter ◽  
The Relationship

This study was conducted to evaluate some aspects of the reproductive biology of the African Bonytongue Heterotis niloticus from the Great Kwa River, Cross River State Nigeria with the view to encourage conservation and rational measures for sustainable management of the species. A total of 62 matured H. niloticus were sampled and their gonadosomatic index (GSI), hepatosomatic index (HSI), condition factor, fecundity and egg diameter (mm) were studied in other to determine the spawning season of the fish. Gonadosomatic index and hepatosomatic index showed an inverse relationship during spawning seasons. Total length (TL-cm) ranged between 47.1 cm – 76.2 cm and total weight (TW – g) ranged between 4300g - 1169g with sex ratio of 1:1.2 (male: female) revealing a dominant female population. Fecundity ranged from 511 oocytes (48.4cm TL; 1.69 kg wt, 5.9g gonad weight) to 7822 oocytes (69.3cm TL, 3.11kg wt. 14.9g gonad weight). The regression equation derived from the scattered diagram in the relationship between fecundity and total weight, total length gonadosomatic index and length-weight is; F= 6.6231TW0.837, R2= 0.2456; F= 5.1112TL1.6367,  R2= 0.1606; F= 10680GSI0.9276, R2= 0.6567; TW= 0.4072TL2.0987, R2= 0.7533, the relationship were significant (p < 0.05). Fecundity and ovary weight relationship showed a positive correlation coefficient of 1. The highest egg diameter (0.92±0.01) was recorded in May and other months with corresponding high gonadosomatic index performance to confirm spawning period. In view to encourage conservation by investigating measures for sustainable management of the species, this study observed that H. niloticus spawns throughout the year. Ikot, N. U. | Department of Zoology and Environmental Biology, University of Calabar, P.M.B.1115 Calabar, Nigeria

scholarly journals Reproductive Biology of Coral Catshark Atelomycterus marmoratus (Anonymous [Bennett], 1830) in Seribu Islands, Indonesia

2019 ◽  
Vol 20 (8) ◽  
Author(s):  
Selvia Oktaviyani ◽  
WANWAN KURNIAWAN ◽  
FAHMI
Keyword(s):  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Maturity Stage ◽  
Total Length ◽  
Mean Size ◽  
The Mean ◽  
First Maturity ◽  
The Relationship ◽  
Monthly Variations ◽  
Size At First Maturity

This study provides information on the reproductive biology of the coral catshark caught in the waters around Seribu Islands, Indonesia. A total of 257 coral catsharks were collected from February 2017 to January 2018. The total length of coral catshark ranged from 170 to 585 mm for females and 255-575 mm for males, respectively. The total weight of females ranged from 85 to 640 g and males from 100 to 620 g The sex ratio between females and males was 0.45 and it was not significantly different from the expected 1:1 ratio. The growth pattern of coral catsharks in Seribu Island was negatively allometric and the population was dominated by mature sharks. The mean size at first maturity was estimated to be 557 mm for females and 514 mm for males, based on to the relationship between the proportion between maturity stage and total length. The ovulation season was estimated occur from October to March, whereas September to April was mating season based on monthly variations of gonadosomatic index (GSI) values and the occurrence of egg cases in uterus.

scholarly journals Kültür Koşullarında Astacus leptodactylus (Eschscholtz, 1823)'un Yumurta Verimliliğinin Belirlenmesi

2019 ◽  
Vol 7 (4) ◽  
pp. 646
Author(s):  
Gülşen Uzun Gören ◽  
Sedat Karayücel ◽  
Birol Baki
Keyword(s):  
Negative Relationship ◽  
Live Weight ◽  
Strong Relationship ◽  
Culture Conditions ◽  
Total Weight ◽  
Astacus Leptodactylus ◽  
Total Length ◽  
The Mean ◽  
Egg Diameter ◽  
The Relationship

In this study, it was aimed to determine there and fecundity by adapting crayfish (Astacus leptodactylus) obtained from Bafra Fish Lakes (Ulugöl-Samsun) in culture conditions. Crayfish obtained in November 2016 were stocked in tanks and egg and morphometric characteristics of female crayfish with carrying eggs were determined. Correlation analysis were used for the relationship between the determined parameters. The mean total weight and total length of crayfish were 41.79±3.00g, 10.72±0.22cm, respectively whereas the mean number and diameter of eggs were 156.40±33.24 and 2.50±0.12mm. There were positive strong relationship between total length and total weight of crayfish negative relationship was found between egg diameter and total number of eggs, egg diameter and total weight of eggs and egg diameter and number of eggs for per unit of live weight.

scholarly journals BIOREPRODUKSI DAN HUBUNGAN PANJANG-BOBOT TERHADAP FEKUNDITAS PADA IKAN LALAWAK (Barbonymus balleroides)

2017 ◽  
Vol 11 (4) ◽  
pp. 339 ◽  
Author(s):  
Irin Iriana Kusmini ◽  
Fera Permata Putri ◽  
Vitas Atmadi Prakoso
Keyword(s):  
Body Weight ◽  
Body Length ◽  
Gonadosomatic Index ◽  
Natural Habitat ◽  
The Body ◽  
Gonad Weight ◽  
Length Relationship ◽  
Negative Impacts ◽  
Egg Diameter ◽  
The Relationship

Eksploitasi ikan lalawak (Barbonymus balleroides) yang berlebihan dari alam mengakibatkan langkanya jenis ikan ini di beberapa perairan aslinya. Sebelum ikan ini diperkenalkan sebagai komoditas budidaya, masih diperlukan lebih banyak lagi informasi mengenai aspek bioreproduksi ikan lalawak yang telah dipelihara pada lingkungan budidaya. Tujuan dari kegiatan ini adalah untuk mengevaluasi produktivitas ikan lalawak yang dipelihara pada lingkungan budidaya melalui pengamatan bioreproduksi dan hubungan panjang-bobot terhadap fekunditas. Sampel induk ikan lalawak betina yang diambil sebanyak 15 ekor, kemudian dipilih lima ekor induk betina yang telah matang gonad dengan ciri-ciri seluruh badannya terasa kasar apabila diraba, perut membesar ke arah posterior dan terasa lunak, genital mengembang, serta berwarna kemerahan. Data yang dikoleksi berupa panjang total, bobot badan, bobot gonad, fekunditas, diameter telur, dan indeks kematangan gonadnya. Hasil penelitian menunjukkan bahwa kisaran fekunditas ikan lalawak adalah 1.920-2.236 butir/g bobot gonad, dan 83-352 butir/g bobot badan induk dengan rata-rata diameter telur 0,87-1,10 mm. IKG berkisar 3,73%-18,36% dari kisaran bobot induk 85,32-264,8 g. Hubungan antara bobot badan dengan bobot gonad ikan lalawak digambarkan dengan persamaan linear y= 5,829ln (x) + 0,691 (r= 0,874); sedangkan hubungan panjang badan terhadap bobot gonad digambarkan dengan persamaan y= 28,52ln (x) - 38,10 (r= 0,7487). Pada ikan lalawak, hubungan bobot badan dengan fekunditas lebih erat dibandingkan dengan hubungan panjang badan terhadap fekunditas. Hasil pengamatan juga menyimpulkan bahwa ikan lalawak tergolong ikan yang memijah secara parsial.Over-exploitation of lalawak (Barbonymus balleroides) from its natural habitat had significant negative impacts on its availability. Before it is introduced as aquaculture commodity, more information about its reproductive biology in aquaculture environment needs to be well observed. The aim of this study was to determine the productivity of lalawak reared in aquaculture environment through observation of bioreproductionand relationship between fecundity and body length-weight of lalawak. Samplewas randomly taken from fifteen individuals female. From those samples, gonads were taken from five mature females for reproduction observation, by which the mature females were selected following specific criteria such as : their body feels rough if touched;enlarged abdomen posteriorly and felt soft; fluffy and reddish genital. Data collection consisted of measurement of the total length, body weight, gonad weight, fecundity, egg diameter and gonadosomatic index (GSI). The results revealed that the fecundity of lalawak ranged from 1,920 to 2,236 eggs/gof gonad weight and 83 to 352 eggs/g of body weight with average diameters of eggs ranged from 0.869 to 1.10 mm. GSI values ranged from 3.73 to 18.36% of 85.32 to 264.8g of body weight. The relationship between body weight and gonad weight of lalawak was described by the linear equation of y= 5,829ln (x) + 0.691 (r= 0.874), while the body length relationship to the gonad weight was described by the equation of y= 28,52ln (x) - 38.10 (r= 0.7487). Fecundity relationship with body weight of lalawak was closer than the length. The observations also concluded that lalawak is classified as partial spawning.

Fecundity and gonadosomatic index of Labeo calbasu (Hamilton) from a stocking pond of a hatchery at Faridpur, Bangladesh

2015 ◽  
Vol 41 (1) ◽  
pp. 43-48
Author(s):  
MA Kabir ◽  
MMA Quddus
Keyword(s):  
Body Weight ◽  
Gonadosomatic Index ◽  
Cyprinid Fish ◽  
Gonad Weight ◽  
Ovary Weight ◽  
Total Length ◽  
Closed Water ◽  
The Relationship

Fecundity, gonadosomatic index (GSI) and ova diameter of the cyprinid fish Kalibaush (Labeo calbasu,Ham.) were studied from a closed water hatchery pond, Faridpur district during April 2007 to March 2008. Fecundity of the fish ranged from 37454 to 427030 with an average 230242. The maximum fecundity was from a fish with total length of 51.3 cm and 1785 g in weight and minimum from a fish with a total length of 32.5 cm and 720 g in weight. The number of ova present per gram of body weight was 213.13 and the number of ova present per gram of ovary weight was 1359.17. It was observed that the fish spawned once in a year with one spawning peak in the month of July as indicated by the values of both ova diameter (1.3± 0.04) and gonadosomatic index (1.68± 0.11 and 18.58 ± 0.06) respectively. The relationship between fecundity and other variables (Total length, body weight and gonad weight) was linear and significant (P<0.01).Bangladesh J. Zool. 41(1): 43-48, 2013

Studies on fecundity and spawning of blue crab (Callinectes Amnicola) in Cross River Estuary

2021 ◽  
Vol 36 (1) ◽  
pp. 75-82
Author(s):  
J. Otoyo ◽  
S.M. Ameh ◽  
O.K. Achema
Keyword(s):  
Blue Crab ◽  
Egg Size ◽  
Gonadosomatic Index ◽  
Carapace Width ◽  
River Estuary ◽  
Hepatosomatic Index ◽  
Cross River ◽  
The Cross ◽  
Cross River Estuary ◽  
Egg Diameter

Studies on identification of species, fecundity and development stages of blue crab, (Callinectes amnicola) were investigated at the Cross River Estuary between the months of December, 2018 and May, 2019. The parameters used for the study were gonadosomatic and hepatosomatic indices, egg diameter and counts. All measurements followed standard procedures. Gonadosomatic index was at its peak in December (88.9) and April (83.3). This coincided with the peak in egg size suggesting that spawning occurred twice within the period.The low values of hepatosomatic index around December (1.20) and April (0.45) added to confirm the spawning in these months. The species spawns at a mean egg size of 17.55mm. The dimension of crabs examined were in the following range: carapace length 40.0 to 70.0mm, carapace width, 5.0 to 60mm and body weight 40.0 to 140.0g. The relationship between fecundity and weight of crab was  significant (r = 0.295: p<0.05), indicating positive correlation. Absolute fecundity of the species ranged between 1,375 and 225,132 eggs. The smallest crab with egg had a carapace width of 39.5mm and weight of 46.9g. Spawning at this size seems to be a strategy adopted by the species to cope with exploitation pressure. The result of this study revealed that C. amnicola had a high reproductive potentials. Hence, adequate regulation is required to enhance sustainability of the species in the Cross River Estuary.

Some aspects of reproductive biology of Gobius paganellus (Gobiidae) on the north-eastern coasts of Tunisia (Bizerta lagoon)

2013 ◽  
Vol 93 (8) ◽  
pp. 2235-2246 ◽  
Author(s):  
Ibtissem Louiz ◽  
Mossadok Ben Attia ◽  
Oum Kalthoum Ben Hassine
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Length Distribution ◽  
Sexual Cycle ◽  
Hepatosomatic Index ◽  
Gobiid Fish ◽  
Spawning Period ◽  
North East ◽  
Bizerta Lagoon

The rock goby, Gobius paganellus one of the most common gobiid fish in Bizerta lagoon (north-east of Tunisia), is a gonochoric species that belongs to the Gobiidae family. This study provides the first detailed information of its reproductive biology in lagoon environments. Gobius paganellus was sampled monthly from January 2005 to December 2006 involving 1486 specimens. Total length distribution ranged between 38 and 125 mm. The maximum recorded total lengths were, respectively, 122 mm and 125 mm for female and male. Over the entire population, the sex-ratio was unbalanced in favour of females. According to months, a predominance of females sex-ratio was recorded during the spawning period while according to body size, males were dominating among larger size-classes. In both sexes, the variation of the gonadosomatic index (GSI) was independent of size. Macroscopic and microscopic examination of the gonads added to the monthly monitoring of gonadosomatic index and hepatosomatic index showed that gonads development begins in October and spawning period extends from December to March. The cyclic pattern of gonads development was determined by histology. Results indicated that G. paganellus exhibits a group-synchronous oocyte development. The sizes of first sexual maturity related to 50% of mature individuals were 78.3 mm (CI95: 77–84 mm) for males and 79 mm (CI95: 75–85 mms) for females. The discussion part underlined the impacts of some environmental factors and antropization of this lagoon on sexual cycle of G. paganellus.

scholarly journals Fecundity and gonadosomatic index of Glossogobius giuris (Hamilton, 1822) from the Payra River, Patuakhali, Bangladesh

2014 ◽  
Vol 2 (2) ◽  
pp. 141 ◽  
Author(s):  
Animesh Roy ◽  
Md. Shakhawate Hossain ◽  
Mohammad Lutfar Rahman ◽  
Mohammad Abdus Salam ◽  
Mir Mohammad Ali
Keyword(s):  
Body Weight ◽  
Gonadosomatic Index ◽  
Fish Population ◽  
Mean Value ◽  
Gonad Weight ◽  
Weight Relationship ◽  
Total Length ◽  
Breeding Technique ◽  
The Mean ◽  
Glossogobius Giuris

Glossogobius giuris were collected during March to September 2013 from the Payra river to estimate the length-weight relationship with relative condition factor (Kn), fecundity, gonadosomatic index (GSI) and relation between fecundity and other parameters. The length-weight relationship was found to be Log W= 2.667 Log TL – 1.805 in male and Log W = 2.931 Log TL – 2.040 in female. The mean Kn were found to be 1.02±0.155 for male and 0.97±0.276 for female which indicates satisfactory condition of the fish population. The mean relative fecundity was ranged from 88495 to 264104 with a mean value of 171581±17855, having a average total length of 21.21±0.44 cm, body weight 70.22±4.62 g and gonad weight 2.74±0.31 g. The relationships among the fecundity, the total length, body weight, gonad weight were found to be linear and positively correlated. The mean GSI value was 3.42±0.33 and the highest GSI value was recorded 9.34±0.71 in the month of September. This study will help to introduce this species in sustainable aquaculture through proper management and for the development of induced breeding technique.

scholarly journals ASPEK BIOLOGI REPRODUKSI DAN POLA PERTUMBUHAN IKAN UCENG (Nemacheilus fasciatus) DALAM PEMELIHARAAN DI AKUARIUM

2017 ◽  
Vol 12 (2) ◽  
pp. 67 ◽  
Author(s):  
Vitas Atmadi Prakoso ◽  
Jojo Subagja ◽  
Anang Hari Kristanto
Keyword(s):  
Body Weight ◽  
Reproductive Biology ◽  
Growth Pattern ◽  
Gonadosomatic Index ◽  
Natural Habitat ◽  
Economic Value ◽  
Black Spot ◽  
Total Length ◽  
Central Java ◽  
Artificial Environment

Ikan uceng (Nemacheilus fasciatus) merupakan salah satu spesies ikan air tawar di Indonesia dengan nilai ekonomi cukup tinggi yang ketersediaannya masih mengandalkan penangkapan di alam, sehingga diperlukan upaya domestikasi untuk menjaga kelestariannya. Tujuan dari kegiatan ini adalah untuk mengamati biologi reproduksi dan pola pertumbuhan ikan uceng di lingkungan buatan (akuarium). Ikan uceng hasil tangkapan alam dari Sungai Progo, Temanggung, Jawa Tengah (panjang total 5,55 ± 0,53 cm; bobot 2,49 ± 0,24 g) diadaptasikan selama 12 bulan di akuarium (40 cm × 30 cm × 30 cm) dengan sistem air mengalir yang dilengkapi dengan aerator. Ikan uceng diberi Tubifex, hingga sampai akhirnya dapat beradaptasi dengan pakan komersial. Pakan komersial yang diberikan yaitu sebesar 3% per hari dari biomassa tubuh dengan frekuensi dua kali sehari. Data biologi reproduksi diperoleh melalui koleksi data panjang total, bobot badan, bobot gonad, fekunditas, diameter telur, dan indeks kematangan gonad. Data pola pertumbuhan diperoleh dengan koleksi data panjang, bobot, dan sintasannya. Hasil penelitian menunjukkan bahwa induk betina yang gonadnya berkembang mempunyai warna bintik hitam yang jelas, sebaliknya induk jantan warna bintik hitam memudar. Indeks kematangan gonad (IKG) yang diamati pada ikan uceng setelah 12 bulan pemeliharaan yaitu berkisar antara 0,007-0,027 pada jantan dan 0,13-0,25 pada betina. Kisaran diameter telur yang diamati yaitu berkisar antara 0,61-0,68 mm, dengan fekunditas 680-4.198 butir. Sedangkan pola pertumbuhannya menunjukkan bahwa ikan uceng betina dan jantan memiliki pola pertumbuhan allometrik negatif (b= 2,739 pada betina; b= 2,895 pada jantan). Nilai faktor kondisi Fulton (K) pada ikan uceng yang diamati yaitu 0,44-1,07 (rata-rata ± SD: 0,70 ± 0,11) pada betina dan 0,37-0,72 (rata-rata ± SD: 0,60 ± 0,06) pada jantan. Dari pengamatan ini ditemukan bahwa proses perkembangan kematangan gonad ikan uceng di akuarium lebih lambat dibandingkan ikan uceng di habitat aslinya.Barred loach (Nemacheilus fasciatus) is one of native fish species in Indonesia with high economic value, where their availability still depends on wild capture. Thus, domestication is needed to maintain its sustainability. The purpose of this study was to observe the reproductive biology and growth pattern of barred loach reared in aquarium (artificial environment). Fish were collected from Progo River, Temanggung, Central Java (total length of: 5.55 ± 0.53 cm; body weight: of 2.49 ± 0.24 g). The fish were reared for 12 months in aquarium (40 cm × 30 cm × 30 cm) with flowthrough system and equipped with aeration. The fish were fed with Tubifex until they accepted commercial feed. Then, the fish were fed twice a day at a ratio of 3% from the total fish biomass. The reproductive biology data were collected by measuring their total length, body weight, gonad weight, fecundity, egg diameter, and gonadosomatic index. Growth pattern were measured from length, weight, and survival. The results showed that matured female had shown black spot and male had inconsistent formation of black spots on their body. The gonadosomatic indexes ranged between 0.007-0.027 for male and ranged between 0,13-0,25 for female. The egg diameters ranged between 0.61-0.68 mm, with the fecundity of 680-4198 eggs. The result of observation on growth pattern showed that female and male had negative allometric growth (b= 2.739 for female, b= 2.895 for male). The value of Fulton condition factor (K) in the observed fish was 0.44-1.07 (mean ± SD: 0.70 ± 0.11) on female and 0.37-0.72 (mean ± SD: 0.60 ± 0.06) on male. From this study, it was found that gonad maturity development of barred loach reared in aquarium was slower than those in their natural habitat.

scholarly journals FEKUNDITAS DAN DIAMETER TELUR IKAN TERBANG DI PERAIRAN SELAT MAKASSAR DAN UTARA BALI

2017 ◽  
Vol 3 (3) ◽  
pp. 191
Author(s):  
Firman Ferdiansyah ◽  
Augy Syahailatua
Keyword(s):  
Strong Relationship ◽  
Gonad Weight ◽  
The Third ◽  
Weak Relationship ◽  
Total Length ◽  
Maturity Stages ◽  
Egg Diameter

Fekunditas dan diameter telur ikan merupakan bagian dari studi reproduksi biologi perikanan. Aspek ini dikaji dari tiga jenis ikan terbang, yaitu Cheilopogon cyanopterus, Hirundichthys oxycephalus, dan Parexocoetus mento yang dikumpulkan dari hasil tangkapan nelayan dengan jaring insang hanyut di perairan Takalar (Selat Makassar) dan Pemuteran (Bali Utara). Jumlah contoh yang diamati 58 gonad ikan betina yang berada pada tingkat kematangan gonad III dan IV. Fekunditas tertinggidimiliki oleh Parexocoetus mento, namun rata-rata fekunditas tertinggi dimiliki oleh jenis Hirundichthys oxycephalus. Korelasi antara fekunditas dan panjang total ikan memiliki tingkat keeratan yang rendah, sedangkan korelasi antara fekunditas dan bobot gonad memiliki tingkat keeratan yang kuat. Distribusidiameter telur ikan pada ketiga jenis ikan terbang ini tidak menunjukan perbedaan yang signifikan, namun secara umum diameter telur pada tingkat kematangan gonad III (0,33-2,21 mm) lebih kecil dari pada tingkat kematangan gonad IV (0,45-2,36 mm). Penelitian ini memberikan indikasi bahwaterdapat variasi fekunditas dan diameter telur antar jenis ikan terbang, serta lokasi penangkapan ikan terbang yang dilakukan oleh nelayan lokal saat ini merupakan daerah pemijahan. Fish fecundity and egg diameter are essential aspects in the study of fishery biological reproductive. These two aspects were observed on three species of fyingfish Cheilopogon cyanopterus, Hirundichthys oxycephalus, and Parexocoetus mento which collected from fishermen caught used a drift gillnet in the waters of Takalar (Makassar Strait) and Pemuteran (north Bali). Numbers of samples examined were 58 gonads of flyingfish at the third (develop) and fourth (mature) maturity stages. The higest fecundity was in the gonad of Parexocoetusmento, however the highest of fecundity mean was in Hirundichthys oxycephalus. The correlation between fecundity and total length shows a weak relationship, however the correlation between fecundity and gonad weight show a strong relationship. Egg diameter of these three flyingfish species had no significant different, but generally egg diameter of develop gonad (0.33-2.21 mm) was smaller than the mature one (0.45-2.36 mm). This study indicates variability in fecundity and eeg diameter among flyingfish species. In addition, the fishing grounds also indicates spawing grounds.

Reproductive cycle of the blue jack mackerel, Trachurus picturatus (Bowdich, 1825), off the Portuguese continental coast

2019 ◽  
Vol 32 ◽  
pp. 14
Author(s):  
Ana Maria Costa
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Condition Factor ◽  
Stock Assessment ◽  
Gonadosomatic Index ◽  
Biological Information ◽  
Hepatosomatic Index ◽  
Jack Mackerel ◽  
First Time ◽  
Monthly Variations

This work provides for the first time a description of the reproductive biology of Trachurus picturatus in Portuguese continental waters (between 41° 49′ and 36° 57′ latitude North). From January 2010 to December 2016 a total of 7409 individuals were sampled from bottom trawlers operating on the northwestern coast of Portugal. The observed sex ratio was 0.56 in favor of the females. Monthly variations in gonadosomatic index, proportion of actively spawning individuals, hepatosomatic index and Fulton′s condition factor were analyzed. More than 60% of spawning individuals were recorded in the first quarter, corresponding to the highest values of GSI, and Fulton's K and hepatosomatic index increased after the start of spawning. The morphometric relationships between total length and gutted weight showed significant correlations (high determination coefficient, r2 > 0.9) and isometric growth (b = 3) for both sexes. Results indicate that the spawning season of T. picturatus starts in December and extends until April–May, with a peak in March, which agrees with what has been indicated by other authors for the northeast Atlantic. This work provides important biological information on a species that although not subject to stock assessment is currently the 5th species landed by weight in Portuguese continental waters.

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