A quantitative description of the reproductive biology of the Mediterranean blenny Aidablennius sphynx (Teleostei, Blenniidae) in its natural habitat

1996 ◽  
Vol 46 (4) ◽  
pp. 329-342 ◽  
Author(s):  
Sarah B. M. Kraak
Author(s):  
Ambo Tuwo ◽  
Chantal Conand

The aspidochirote Holothuria forskali is a large common species found in the Atlantic and the Mediterranean. Its reproductive cycle has been determined in a population from Brittany using histological observations of the different classes of gonadal tubules, oocyte size frequencies and evolution of gonad indices. The cycle is annual and synchronous in both sexes. The different phases are well marked and are characterized by a long maturation during summer and autumn followed by a pre-spawning period during winter. Spawning is probably related to the increase in temperature. Most of the mature gametes are released. The resorption of the relict and spent tubules continues during the onset of the next vitellogenesis in the secondary tubules, without a rest period. The reproductive effort, documented from the gonad indices, is very high in this population which is composed of adult individuals.


2012 ◽  
Vol 50 (1) ◽  
pp. 67-73 ◽  
Author(s):  
María Francisca Colom ◽  
Ferry Hagen ◽  
Alfonso Gonzalez ◽  
Axelle Mellado ◽  
Neus Morera ◽  
...  

2002 ◽  
Vol 66 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Guiomar Rotllant ◽  
Joan Moranta ◽  
Enric Massutí ◽  
Francisco Sardà ◽  
Beatriz Morales-Nin

Author(s):  
Eva Graciá ◽  
Roberto Carlos Rodríguez-Caro ◽  
Marcos Ferrández ◽  
Albert Martínez-Silvestre ◽  
Irene Pérez-Ibarra ◽  
...  

Chelonians are among the animal groups with the poorest conservation status. Since tortoises are long-lived species that need very long time to reach sexual maturity, they are extremely vulnerable to human pressure. Despite their endangered status, there are no common strategies for the development of conservation actions. At the “Mediterranean workshop to develop tortoise conservation strategies”, scientists, conservation associations, environmental managers, IUCN advisers and CITES inspectors met in October 2019 in Alicante (Spain). The aims were to update the diagnosis of the conservation status of the Hermann’s tortoise (Testudo hermanni) and the spur-thighed tortoise (Testudo graeca) and to suggest strategies that guarantee their preservation at the Mediterranean Region. The main conclusions are summarized by: i) Mediterranean tortoises are wild endangered species that must be protected in, and together with, their natural habitat. Their main threats are habitat loss and fragmentation and pet trade, but we should also pay attention to wildfires, spread of diseases, the introduction of exotic species or lineages and climate change. ii) Long-term efforts and stablished protocols are needed to accurately diagnose and monitor the conservation status of wild populations, as well as flows among captive and wild animals. iii)  Tortoise trade should be banned because it threatens the conservation of wild populations of tortoises. Illegal practices related to tortoises should be decidedly persecuted. People should consider tortoises as wild animals that are endangered and deserving of protection. It is possible to enjoy them by responsibly observing them in their habitat. iv) Tortoises may carry pathogens or parasites and their sanitary status cannot be fully assessed. They should always be considered potential vectors of tortoise diseases and of zoonosis. Hygiene protocols should be implemented when managing them. v) The researchers attending this workshop aimed to develop a scientific network for the long-term monitoring of graeca and T. hermanni populations in the Mediterranean Region. They will need the support from public administrations.  


2017 ◽  
Vol 12 (2) ◽  
pp. 67 ◽  
Author(s):  
Vitas Atmadi Prakoso ◽  
Jojo Subagja ◽  
Anang Hari Kristanto

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.


Author(s):  
R. H. Emson ◽  
R. G. Crump

This paper describes a new asterinid starfish found first in southern Britain, but now also known from the Mediterranean and the Adriatic. Detailed comparison is made between the new species and the closely related Asterina gibbosa in terms of morphology, reproductive biology and life-history. The new species is adapted for life on the upper parts of rocks and on perennial algae in intertidal rock pools; it is small in size, matures early, lays large eggs, broods its young and has a short life span.


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