scholarly journals Ex situ protection of the European mudminnow (Umbra krameri Walbaum, 1792): Spawning substrate preference for larvae rearing under controlled conditions

2016 ◽  
Vol 68 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Balázs Kucska ◽  
Péter Kabai ◽  
Juraj Hajdú ◽  
Levente Várkonyi ◽  
Dániel Varga ◽  
...  

Captive breeding programs of endangered fish species, such as the European mudminnow Umbra krameri, are essential for population restoration. To improve captive spawning and larvae rearing under controlled conditions, two experiments were carried out. In the first, the spawning substrate preference was tested in triplicate, where five different types of artificial surface were provided for mudminnow pairs:(i)sand, (ii)artificial plants, (iii)gravel, (iv)sand + artificial plants and(v)gravel + artificial plants. All fish preferred the gravel + artificial plant combination, which indicates that this type of surface could be the most appropriate for spawning in captivity. In the second trial, three feeding protocols were tested in triplicate under controlled conditions. In the first treatment fish were fed exclusively with Artemia nauplii; in the second treatment fish were fed with Artemiafor the first ten days then Artemia was gradually replaced with dry feed; for the third group the transition period started after 5 days of Artemia feeding. Although the survival rate of larvae could be maintained at a high level in some of the feeding protocols, a strong decrease in the growth rate was obvious in all diets containing dry food, which means that live food is essential for the first three weeks of mudminnow larvae rearing.

2020 ◽  
Author(s):  
Isaac Okyere ◽  
Juliet Afrah Obeng ◽  
Samuel Ayitey ◽  
Jouke Rients Van der Zee ◽  
Herman Meeus

Abstract Aside from ornamental uses of killifishes, there is growing interest in using killies for a multiplicity of purposes including baitfish and mosquito biocontrol. This experiment explored the spawning habits and embryonic development of the banded lampeye, Aplocheilichthys spilauchen in ex situ freshwater (0.04 ‰) and brackish water (5.01 ‰) to ascertaining the captive breeding prospects for mosquito control in areas where they occur. Significantly higher number of eggs were laid in the brackish water than the freshwater (ꭓ2 = 1613.0, P < 0.05), and black mop was the most preferred spawning substrate, followed by green, blue and white mops. Microscopic monitoring of embryos revealed that cleavage occurred within the first 30 minutes after fertilisation, organogenesis commenced in averagely the 25th hour, and hatching in approximately 230 hours. Although certain embryonic developmental stages occurred faster in the freshwater than brackish water and freshwater eggs were relatively bigger than brackish water eggs, these differences were overall not significant and had no effects on the development and hatching. The observed outcome that A. spilauchen can be optimally propagated with black mops in brackish water offers a significant step in its use for the mosquito biocontrol programme, as well as other potential uses not yet explored.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2191
Author(s):  
Pablo García-Salinas ◽  
Victor Gallego ◽  
Juan F. Asturiano

The chondrichthyan fishes, which comprise sharks, rays, and chimaeras, are one of the most threatened groups of vertebrates on the planet. Given this situation, an additional strategy for the protection of these species could be the ex situ conservation projects developed in public aquaria and research centers. Nevertheless, to increase sustainability and to develop properly in situ reintroduction strategies, captive breeding techniques, such as sperm extraction and artificial insemination, should be developed. These techniques are commonly used in other threatened species and could be also used in chondrichthyans. However, the different reproductive morphologies found in this group can complicate both processes. Therefore, a comparison of the reproductive anatomy of eight distinct chondrichthyans, with an emphasis on those important differences when performing sperm extraction or artificial insemination, is carried out herein. Sharks and chimaeras belonging to the Scyliorhinidae, Carcharhinidae, Centrophoridae, Etmopteridae, Hexanchidae, and Chimaeridae families were obtained from commercial fisheries, public aquaria, and stranding events. In addition, the process of obtaining viable sperm samples through cannulation, abdominal massage, and oviducal gland extraction is described in detail for both living and dead animals.


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2986
Author(s):  
Joan Manubens ◽  
Oriol Comas ◽  
Núria Valls ◽  
Lluís Benejam

The strong decline of freshwater fish species in Europe implies that further ex-situ conservation plans should be implemented in the near future. The present study reflects our experience with the Pyrenean sculpin (Cottus hispaniolensis Bacescu-Mester, 1964)—a small cottid endemic to the Hispano-French Garona River basin. In recent years, the Spanish Pyrenean sculpin population has reached a limit situation. Because of that, the non-profit association ADEFFA—with support from the public administration—started the first captive breeding program for this species in 2006. Fourteen years later, this study presents the results and evaluates the different steps of the program, with the aim of discussing and improving the ex-situ conservation plans for this and other cold freshwater species. There is a description and a comparison between six consecutive phases during the captive breeding process: nesting behaviour, courtship, egg fixation, parental care (incubation), hatching and survival during juvenile development. The purposes of this project are to: (1) identify the most determining phases for a successful captive breeding; (2) identify the factors that had a major influence to the success of the critical phases; and (3) increase the number of the offspring. This study is based on thirty-three wild individuals collected from Garona River (Val d’Aran, Spanish Pyrenees). During the program, twelve couples spawned in captive conditions, with around 2300 eggs laid. Eight couples bred successfully, with 751 hatched individuals and 608 juveniles reared. The analysis of each step of the captive breeding does not reveal significant differences between phases, so it can be concluded that they are all critical at the same level. In the literature, similar study-cases of captive breeding programs identify incubation and survival phases as the most critical. Consequently, the management made for this project has probably allowed to overcome in part the main impediments described in other similar programs.


2020 ◽  
Vol 48 (3) ◽  
pp. 440-445
Author(s):  
Dilberto Ribeiro Arashiro ◽  
George Shigueki Yasui ◽  
Leonardo Luiz Calado ◽  
Nivaldo Ferreira Do Nascimento ◽  
Silvio Carlos Alves do Santos ◽  
...  

This study aimed to describe a procedure for sampling, reproduction, and first feeding of the Neotropical catfish Pseudopimelodus mangurus, an endangered fish species. Wild adult P. mangurus specimens were collected in the Mogi Guassu River and subsequently induced to spawn in laboratory conditions. After hand-stripping, the females, the average weight of the oocytes was 143 ± 1.6 g, with a fecundity of 718 ± 49.8 oocytes g-1. The diameter of the oocytes non-hydrated was 1,226.3 ± 47.7 μm to 1,761.2 ± 26.4 μm after hydration. The fertilization rates were 98.00 ± 0.63%, and the hatching rate was 68.94 ± 11.83%. The first feeding was made three days post-hatching with six different treatments, in which the best results arose with sequential feeding with Artemia nauplii, Astyanax altiparanae and Prochilodus lineatus larvae. This condition resulted in a final length of 2,012.7 ± 44.8 μm by the 10th day of the experiment, higher survival (65 ± 0.9%) and lower cannibalism rate (14 ± 0.3%). The data obtained in this study is important for the establishment of reproductive biotechniques, mass production of P. mangurus, and future establishment of ex-situ GenBank.


2015 ◽  
Vol 52 (4) ◽  
pp. 841-850 ◽  
Author(s):  
Paul M. Dolman ◽  
Nigel J. Collar ◽  
Keith M. Scotland ◽  
Robert. J. Burnside

2014 ◽  
Vol 60 (4) ◽  
pp. 486-499 ◽  
Author(s):  
Tim Caro ◽  
Jason Riggio

Abstract We examine the conservation status of Africa’s “Big Five”: lion, leopard, buffalo, black and white rhinoceros and elephant, and the role of behavioral knowledge in their conservation. Efforts to conserve these flagship species consist of in situ conservation, captive breeding and reintroductions. With a few exceptions, we find limited evidence that knowledge of behavior informs conservation programs targeted at these species. For management in the wild, knowledge of infanticide and ranging can provide guidelines for realistic hunting quotas and corridors between protected areas, respectively. For ex situ and reintroduction programs, behavioral knowledge is chiefly focused on improved animal husbandry. Despite a formidable understanding of these species’ behavior, the practicalities of using such knowledge may be diminished because exploitation of these species is so forceful and the bulk of efforts aimed at conserving these species (and indeed most other African species) are primarily in situ where behaviorally driven interventions are limited. Our comparative findings suggest that behavior has been of rather narrow use in the conservation of these flagship species [Current Zoology 60 (4): 486–499, 2014].


2020 ◽  
pp. 1098612X2093019
Author(s):  
Jennifer E Slovak ◽  
Taylor E Foster

Objectives The aim of this study was to determine if cats fed from a commercially advertised whisker-friendly dish vs their normal food dish would spend more time at the food dish, eat more and drop less food. Methods Forty indoor cats were enrolled in the study. Owners fasted their cats for 12 h and fed them their normal measured amount of dry food in their normal dish. Owners filmed their cats eating for up to 5 mins, and measured how much food was eaten and dropped from the dish. Owners then switched to feeding their cats from a whisker-friendly dish for a 7-day transition period. Following this transition, owners were instructed to fast their cats for 12 h and then feed them their normal food from the new dish and film them eating, as previously described. The following day the owners offered food in both dishes to determine their cat’s preference. Results No evidence was found that eating from the whisker-friendly dish increased the amount of time spent eating ( P = 0.8), decreased the amount of food dropped ( P = 0.9) or increased the amount of food eaten ( P = 0.7). The estimated probability for the cats to prefer the whisker-friendly dish was 0.74 with a 95% confidence interval. Conclusions and relevance Cats fed from a whisker-friendly dish did not spend more time eating, drop less food or eat more food in a 5-min period. Some cats appeared to prefer the new whisker-friendly dish over their normal food dish. Overall, food dish-associated whisker stress did not affect the eating habits of the study cats.


2015 ◽  
Vol 1 (5) ◽  
pp. e1400175 ◽  
Author(s):  
Andreas Wilting ◽  
Alexandre Courtiol ◽  
Per Christiansen ◽  
Jürgen Niedballa ◽  
Anne K. Scharf ◽  
...  

Although significantly more money is spent on the conservation of tigers than on any other threatened species, today only 3200 to 3600 tigers roam the forests of Asia, occupying only 7% of their historical range. Despite the global significance of and interest in tiger conservation, global approaches to plan tiger recovery are partly impeded by the lack of a consensus on the number of tiger subspecies or management units, because a comprehensive analysis of tiger variation is lacking. We analyzed variation among all nine putative tiger subspecies, using extensive data sets of several traits [morphological (craniodental and pelage), ecological, molecular]. Our analyses revealed little variation and large overlaps in each trait among putative subspecies, and molecular data showed extremely low diversity because of a severe Late Pleistocene population decline. Our results support recognition of only two subspecies: the Sunda tiger,Panthera tigris sondaica,and the continental tiger,Panthera tigris tigris, which consists of two (northern and southern) management units. Conservation management programs, such as captive breeding, reintroduction initiatives, or trans-boundary projects, rely on a durable, consistent characterization of subspecies as taxonomic units, defined by robust multiple lines of scientific evidence rather than single traits or ad hoc descriptions of one or few specimens. Our multiple-trait data set supports a fundamental rethinking of the conventional tiger taxonomy paradigm, which will have profound implications for the management of in situ and ex situ tiger populations and boost conservation efforts by facilitating a pragmatic approach to tiger conservation management worldwide.


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