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Start Over Creator Bohlen, Jörg

2. First report on the spawning behaviour of a golden spined loach Sabanejewia vallachica (Teleostei: Cobitidae)

Creator:
Bohlen, Jörg
Type:
article and TEXT
Subject:
ecology, reproduction, freshwater fish, and sexual dimorphism
Language:
English
Description:
Very little is known about the spawning behaviour of loach fishes, despite the fact that reproduction is one of the most important aspects in the autecology of animals. Here the spawning behaviour of golden spined loaches of the genus Sabanejewia is described for the first time. In opposite to spined loaches of the genera Cobitis and Misgurnus, the spawning partners do some ‘circle swimming’ together prior to spawning and the male does not form a full ring around the female but catches the female with a ‘V’-shaped body. This spawning behaviour explains why males of Sabanejewia, unlike nearly all other genera of Cobitidae, 1) are not significantly smaller than females, a condition that is required only to form a complete ring around the female,and 2) have swellings in the middle of the body instead of specialised rays of the pectoral fins like in most other genera. These swellings are in the part of the body that touches the female during the release of gametes, while the pectoral fins do not reach to female’s body.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

4. Loaches and the environment in two provinces in Norhern Vietnam

Creator:
Petrtýl, Miloslav, Bohlen, Jörg, Kalous, Lukáš, The Bui, Anh, and Chaloupková, Petra
Type:
article and TEXT
Subject:
biodiversity, the River Pearl, Schistura, Leptobotia, Tracccatichthys, Cobitis, and Misgurnus
Language:
English
Description:
During the last decades, agriculture activities in the mountainous northern provinces of Vietnam intensified drastically, and today rice fields occupy the complete valleys of local streams and rivers. Upstream of the fields, many dams were built mainly for irrigation purposes; sometimes stopping the flow through the lower courses of the creek completely. Illegal fishing with electro-fishing gears is a common way to improve food supply for local villagers. Larger rivers are impacted by non-selective fishing, gravel mining and pollution. These factors represent threats to the local fish communities, which typically include one or several species of loaches.With usage of electro-fishing gear and hand net we surveyed 16 localities of the river basins of the River Ky Cung and the River Bang Giang. Both rivers belong to the drainage area of the River Pearl in the provinces Lang Son and Cao Bang in Northern Vietnam. We focused on getting maximum number of fish species with special attention to loaches at each locality. Ten species of loaches were found; at least two of them represent undescribed species. The main conclusion is that the ichthyofauna of Northern Vietnam still holds a hidden diversity, but at the same time is under strong anthropogenic pressure, so that parts of the diversity may be lost soon.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

5. Sex ratio and body size in Cobitis elongatoides and Sabanejewia balcanica (Cypriniformes, Cobitidae) from a thermal spring

Creator:
Bohlen, Jörg, Freyhof, Jörg, and Nolte, Arne
Type:
article and TEXT
Subject:
environmental sex determination (ESD), Fisher´s principle, cobitine loach, Baile Episcopesti, and dwarfism
Language:
English
Description:
The sex ratio of loach fishes from the warm thermal spring Baile Episcopesti in western Romania was investigated. In Cobitis elongatoides, the sex ratio was balanced, while in Sabanejewia balcanica, males made up 77% of the adult fish. In both species, body size at onset of maturation and maximum length were remarkably smaller than in other populations. Mature males of C. elongatoides measured 35 to 51 mm in total length while the largest female reached 69 mm. Males of S. balcanica measured 40 to 53 mm and the largest female had a total length of 54 mm. We consider both the dwarfism of the fish as well as the male-biased sex ratio in S. balcanica to be caused by the thermal regime in the spring.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

6. Spawning marks in spined loaches (Cobitis taenia, Cobitidae, Teleostei)

Creator:
Bohlen, Jörg
Type:
article and TEXT
Subject:
freshwater fish, reproduction, autecology, population ecology, and synchronisation
Language:
English
Description:
In Cobitis taenia and, with lower intensity, also in C. elongatoides and C. melanoleuca, females bear visible spawning marks on the body sides after spawning events. These marks intensify during the spawning season but disappear a few weeks after the last spawning event. The precise origin of the spawning marks is not clear, but they seem to be produced by the male during embracement of the female. Spawning marks were not observed after spawning events of C. bilineata, C. fahirae, C. rara, C. paludica, C. strumicae and C. turcica. An example dataset from Haaren creek in northwestern Germany is given to demonstrate that these marks can be used as a tool to precisely estimate the start of reproductive season for Cobitis populations, separately even for different size classes.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

7. Two new species of Tanichthys (Teleostei: Cypriniformes) from China

Creator:
Li, Fan, Liao, Te-Yu, Bohlen, Jörg, Shen, Zhi-Xin, Zhao, Liang-Jie, and Li, Shan
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
Cyprinidae, Tanichthyidae, white cloud mountain minnow, cytochrome b, phylogeny, and taxonomy
Language:
English
Description:
Tanichthys albiventris, new species, from the River Jiangping in Dongxing City, Guangxi Province is distinguished from Tanichthys albonubes by the presence of a reddish-orange dorsal-fin margin (vs. white) and 9-10 (9 in mode) branched anal-fin rays (vs. 8 in mode). Tanichthys flavianalis, new species, from the River Jiuqu in Qionghai City, Hainan Province is distinguished from T. albiventris and T. albonubes by the presence of a golden anal-fin margin (vs. white) and 7 (rarely 6) branched dorsal-fin rays (vs. 6 in mode). In T. albiventris, T. albonubes, and T. flavianalis the black lateral stripe is located on the dorsal half of the flank, distinguishing them from Tanichthys kuehnei and Tanichthys micagemmae, in which it is mid-lateral. Tanichthys thabacensis is different from all other species of Tanichthys in the shape of the mouth and insertion of the anal fin; it is tentatively referred to as Aphyocypris.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public