Phenotypic and genetic variation in lumpfish (Cyclopterus lumpus): applications towards sustainable aquaculture of cleaner fish

2020 ◽  
Author(s):  
◽  
Benjamin A. Whittaker

Ectoparasitic lice threaten sustainable Atlantic salmon (Salmo salar) aquaculture, as high farm stocking densities facilitate louse infestation thereby increasing mortality rates. Lumpfish (Cyclopterus lumpus) have recently been demonstrated to remove lice and are increasingly deployed onto farms as cleaner fish. Commercial stocks of lumpfish are now produced in hatcheries to meet growing demand from farms across the Atlantic, however, concern grows regarding the long-term viability of this practise due to insufficient knowledge on lumpfish biology. Challenges include understanding how patterns of genetic and phenotypic variation influence performance, whether desirable traits can inform captive breeding, potential impacts on wild populations and whether intraspecific variation in cleaning behaviour can be optimized. Therefore, this thesis examined genetic and phenotypic variation in lumpfish across multiple biological scales, ranging from populations down to family stocks and individuals, investigating factors influencing aquaculture performance. Chapter 1 found genetic structure in populations across the Atlantic, with limited gene flow separating regions of lumpfish aquaculture. Chapter 2 identified phenotypic differences in the body morphology of stocks, including variation in scutes and body depth of northern and southern phenotypes. Sexual dimorphism was identified in the mouth, flag, hump and caudal peduncle. Chapter 3 showed further phenotypic differences in fitness-related traits, with faster growth, more active swimming and lower survival associated with northern stocks. Chapter 4 developed protocols to quantify lumpfish personality and found that bolder individuals interacted more with salmon, whereas, a syndrome for social-aggression was linked to antagonistic behaviour. Patterns of genetic and phenotypic variation imply population differentiation is reflected in stocks commonly used in aquaculture. Common-garden trials suggested translocated lumpfish show reduced fitness, therefore establishing regionally-specific stocks may benefit performance and minimise detriment to wild populations via introgression through farm escapes. Personality constituted a major source of variation in cleaning behaviour, selecting bold lumpfish could optimise efficiency.

Author(s):  
R. Stavetska ◽  
Y. Dynko ◽  
M. Bushtruk ◽  
I. Starostenko ◽  
O. Babenko ◽  
...  

It has been experimentally proven that the strength and direction of the connection between the linear type traits evaluation of the Ukrainian black-and-white dairy breed cows and their body build depends on the type of the build and the sign of the exterior. The study was conducted in 2018 on a breeding plant of the Ukrainian Black-and-White Dairy breed SPC named Shchorsa in Kiev region (n=89). Differentiation of cows on types of their body build was conducted by the method proposed by Chernenko (low-capacity, mid-capacity and high-capacity types) and Kolesnik (by the massiveness index – on the friable and dense, the bone index – delicate and rough, the wide-breast and wide-rump indices – on narrow-body and wide-body types). It was found that the cow-heiferswere well-developed, had intermediate stature and optimum body condition score, deep body, and wide, slight slope rump. They alsohad desirable rear legs, set and foot angle but some toe-out, the udder was well-balanced. Under the good total score of the exterior of studied cows there were some animals with short stature (134– 136 cm), very wide rump, straight rear legs side view and toe-out, extremely steep foot angle, loose fore udder attachment, deep udder below hocks and front teat placement inside of quarter. The degree of development of the studied linear traits of cow-heifers confirms their in-herd variability. The variability of the exterior traits varies from 10,7 % (body depth) to 38,6 % (stature). In addition to the stature of a significant variability was characterized of angularity (22,4 %), rear legs set (22,5 %), body condition score (21,8 %), as well as traits that describe udder: rear udder attachment (31,4 %), udder depth (32,6 %) and front and rear teat position (31,3 % and 25,1 %, respectively). The high variability of linear traits indicates the possibility of effective their selection. As a result of the research, it has been established that the strength and direction of the correlations between the linear type traits evaluation of Ukrainian Black-and-White Dairy breed cows and the type of their body build depends on the type of the body build and the linear trait. The low-, mid- and high-capacity bodies build types (according to Chernenko) reliably correlate with chest width (r=0,58) and body depth (r=0,48), rear legs rear view (r=0,30), the central ligament (r=0,28), udder depth (r =-0,22) and teat length (r=0,25), P˂0,01–0,001. Friable and dense bodies build (according to Kolesnik) were most strongly associated with stature (r=-0,28), chest width (r =-0,70), and body depth (r=-0,38), as well as with rear legs rear view (r=-0,23), P˂0,05...0,001; delicate and rough bodies build – with stature (r=-0,51), angularity (r=-0,22),rump width (r=-0,35), udder depth (r=-0,27) and rear udder attachment (r =0,20), P ˂ 0,05–0,001; narrow-body and wide-body types – with chest width (r=0,30) and rump width (r=0,23), P˂0,05–0,01. Linear type trait evaluation of cows depends on the body build. The strength and direction of the correlations between types of body build and linear traits showed that the most informative is the classification of the body build by low-, mid- and high-capacity according to Chernenko – on the average η2x=17,5 %. The less informative – by narrow-body and wide-body types according to Kolesnik – η2x=7,6 %. The classification of cows on delicate-rough, narrow-body and wide-body types (according to Kolesnik) according to informativeness and reliability can have the intermediate position – η2x=10,0–11,5 %. The strongest influence on the body build has the cows’ height (η2x=27,9 % on average for all studied types of body build), chest width (η2x=33,5 %), body depth (η2x=21,8 %), rump width (η2x=24,1 %) and rear legs (η2x=18,7 %). Key words: cows, linear type trait evaluation, body build, correlation, power of influence.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Renan Rodrigues Rocha ◽  
Rosana de Mesquita Alves ◽  
Rubens Pasa ◽  
Karine Frehner Kavalco

The Astyanax scabripinnis complex is composed of a large number of almost morphological indistinguishable species, including Astyanax paranae and Astyanax rivularis, which exist in the Paraná and São Francisco Basins, respectively, and sometimes are considered subspecies of the A. scabripinnis group or even are cited just as A. scabripinnis. The two river basins are separated by the Upper Paranaíba Arc, likely the main cause of the isolation of these species. We used geometric morphometric tools and DNA analyses of populations of both species to identify the differences between them. Geometric morphometrics separated the two species into distinct groups, whose main difference was the body depth. This is generally related to the speed of the water flow in the river basins. The maximum likelihood phylogram based on mitochondrial DNA sequences formed two main clades: one composed of the population of A. rivularis and the other, of A. paranae. In the haplotype network, the species were similarly separated into two groups from the same ancestral haplotype, with A. rivularis dispersing into two lineages in the São Francisco River Basin. The distribution of A. paranae is a consequence of a secondary dispersion event in the Paraná River Basin. It forms two lineages from a haplotype derived from the ancestor. The vicariant effect of separate basins, through the elevation of the Upper Paranaíba Arc, led to the allopatric speciation of the populations originating the present species. The results of geometric morphometrics and molecular data of the fish show the importance of this geological event in the biogeography and evolutionary history of the ichthyofauna of the region and indicate that the isolation of these species seems to be effective.


1992 ◽  
Vol 109 (3) ◽  
pp. 423-432 ◽  
Author(s):  
M. A. Deighton ◽  
J. Capstick ◽  
R. Borland

SUMMARYThis study examines a series of phenotypic variants ofStaphylococcus epidermidisthat were generated from a pair of parent variants, isolated from valvular tissue of a patient with prosthetic valve endocarditis. The variants were initially classified by examining their colonial morphology on Congo red agar. In addition to differences in Congo red binding and colonial morphology, they differed in the expression of several surface components and enzymes. Despite these phenotypic differences, all variants had the same restriction endonuclease profile of plasmid DNA. Examination of a collection of clinical isolates demonstrated that phenotypic variation is a common property ofS. epidermidis. The ability to express different combinations of surface components and enzymes could contribute to the virulence ofS. epidermidisstrains by enabling these organisms to colonize a range of diverse environments.


Zootaxa ◽  
2021 ◽  
Vol 4949 (3) ◽  
pp. 499-520
Author(s):  
LUIS ESTEBAN KRAUSE LANÉS ◽  
MATHEUS VIEIRA VOLCAN ◽  
LEONARDO MALTCHIK

Two new species of Austrolebias are described based on specimens collected from temporary pools located in natural grassland landscape within the Araucaria Forest domain at exceptionally high altitudes (~1000 meters a.s.l.). Austrolebias botocudo sp. n. and Austrolebias nubium sp. n. occur, respectively, in drainages of upper rio Apuaê-Inhandava (upper rio Uruguay basin) and upper rio Taquari-Antas (upper rio Jacuí, Laguna dos Patos basin), in the Meridional Plateau of southern Brazil. Despite an intensive survey conducted in the area, only two populations of each species were recorded. Both new species occurs at altitudes that are among the higher recorded for species of the genus, and both are assigned to the subgenus Acrolebias. The new species described herein are easily distinguished for its congeners by the colour pattern of males, by presence of melanophores irregularly distributed in different parts of the body, contact organs cover the body and anal fins, position of fins related with vertebrae, by preopercular and mandibular series of neuromasts united, by a series of morphometric features and by larger maximum standard length. Austrolebias botocudo and A. nubium are distinguished from each other by colour pattern of males, length of contact organs in the flank and number of contact organs in scales of lateral line, dorsal profile of head, number of neuromasts in the preopercular + mandibular series, body depth in females, and by basihyal cartilage length. Additionally, we discuss the conservation status of the new species, and provided an identification key for the species of the subgenus Acrolebias. 


Author(s):  
Miguel Henriques ◽  
Vitor C. Almada

Underwater behavioural observations were conducted to evaluate the relative importance of cleaning behaviour in three species of common north-eastern Atlantic wrasse (Teleostei: Labridae). At the study site, the only cleaner was Centrolabrus exoletus. A total of 12 species was cleaned, with the wrasse, Symphodus melops and Labrus bergylta being the species most frequently cleaned. Neither S. melops nor Ctenolabrus rupestris, known to be cleaners in other sites or in captivity, could be observed cleaning other fishes. Centrolabrus exoletus was found to be a facultative cleaner fish with cleaning acts representing only 7% of the observed feeding acts. In focal observations of host fishes, the incidence of cleaning acts reached a level (11 h-1 per host) similar to that reported for tropical reef fishes and probably reflects the high numbers of cleaners available. Some factors that may affect the origin of the cleaning interactions are discussed.


Zootaxa ◽  
2021 ◽  
Vol 4996 (2) ◽  
pp. 322-330
Author(s):  
HEOK HEE NG ◽  
MAURICE KOTTELAT

Pseudobagarius eustictus, new species, is described from the Nam Heung drainage (a tributary of the Mekong River) in northern Laos. It is distinguished from congeners in having a unique combination of the following characters: a weakly-produced snout in which the upper jaw extends only slightly beyond the margin of the lower jaw when viewed ventrally, 3 tubercles on the posterior margin of the pectoral spine, eye diameter 8% HL, head width 24.1% SL, dark yellow dorsal and lateral surfaces of the head, pectoral spine lacking elongate extensions, pectoral fin reaching the pelvic-fin base when adpressed against the body, dorsolateral surfaces of body without longitudinal series of prominent tubercles, body depth at anus 13.7% SL, length of adipose-fin base 17.7% SL, caudal-peduncle depth 7.0% SL, and 33 vertebrae.  


2011 ◽  
Vol 51 (No. 8) ◽  
pp. 327-333 ◽  
Author(s):  
M. Vacek ◽  
M. Štípková ◽  
E. Němcová ◽  
J. Bouška

The relationships between conformation traits and longevity traits were analyzed in 41 489 Holstein cows born in the years 1994&ndash;1999 which were culled by 30<sup>th</sup> June 2005. Pearson correlation coefficients between type traits and the herd life or productive life of cows were calculated. The effects of type trait scoring level on the length of productive life were described by means of analyses of variance. The observed correlations between herd life or productive life and type traits are in the range of &ndash;0.061 to 0.160. Negative correlations were found for rump angle, rear leg set, udder depth, and teat length. Most of the body traits had slightly positive relationships to herd life, indicating that larger cows live longer. However, body depth and chest width did not have a linear relation to longevity traits. The longest productive life was found in cows undersized in chest width and body depth (P &lt; 0.01). A similar dependence was also found for rump width (P &lt; 0.01). The ideal rear leg set for longevity was scored as average or below average, i.e. moderately curved or slightly straight legs (P &lt; 0.05). Cows with well-attached fore udder, high attached rear udder, strong central ligament, close front teat placement, and with moderately long teats showed the longest functional productive life (P &lt; 0.05&ndash;0.001). Linear relationships between longevity traits and general conformation characteristics were found as well. &nbsp;


Zootaxa ◽  
2019 ◽  
Vol 4674 (3) ◽  
pp. 329-348 ◽  
Author(s):  
JEFFREY W. JOHNSON ◽  
JESSICA WORTHINGTON WILMER

A new species of epinephelid fish from northeastern Australia is described based on five specimens 408–564 mm SL collected by deep water demersal dropline fishing. Epinephelus fuscomarginatus sp. nov. is known from the Capricorn Channel, off the southern end of the Swain Reefs, Qld, Australia, in depths of 220–230 m. It is distinguished by a combination of dorsal-fin rays XI, 14, pectoral-fin rays 17, anal-fin rays III, 8, caudal-fin rounded, lateral-line scales 60–67, gill rakers 9–10 + 16–19 = 25–28, body depth 3.0–3.4 in SL, angle of preopercle broadly rounded, bearing 4–9 small non-prominent serrae, midlateral part of lower jaw with 2 rows of teeth, tooth patches on vomer and palatines narrow, in 2–3 and 2–4 rows, respectively, and coloration including broad dark brown margins to the soft dorsal, anal and caudal fins. There are no dark spots on the head, body, or fins at any known size and in subadults there are two faint pale brown bars radiating from the eye to the posterior margin of the opercle, and diffuse irregular brown wavy bars and blotches on the sides of the body. Comparison of the mitochondrial cytochrome c oxidase subunit 1 (CO 1) genetic marker utilised in DNA barcoding produced modest but consistent genetic divergences of 1.10% and 2.70 % between E. fuscomarginatus sp. nov. and its closest sampled congeners, E. magniscuttis and E. epistictus, respectively. Further evidence is presented to indicate that populations of E. epistictus currently recognised from the Indian Ocean east to the Indo-Australian Archipelago may be distinct from those from the Sea of Japan to the East China Sea. 


Zootaxa ◽  
2019 ◽  
Vol 4603 (2) ◽  
pp. 377 ◽  
Author(s):  
RALF BRITZ ◽  
V.K. ANOOP ◽  
NEELESH DAHANUKAR ◽  
RAJEEV RAGHAVAN

Aenigmachanna gollum, new genus and species, is described from Kerala, South India. It is the first subterranean species of the family Channidae. It has numerous derived and unique characters, separating it from both the Asian Channa Scopoli and the African Parachanna Teugels & Daget. Uniquely among channids, A. gollum has a very slender (maximum body depth only 11.1–11.3% SL), eel-like body (head length 20.8–21.6% SL), large mouth (jaw length 60.4–61.1 % HL), 43–44 anal-fin rays, 83–85 scales in a lateral series, an unusual colour pattern and it lacks pored lateral-line scales on the body and body buoyancy. In addition, it is distinguished by its DNA barcode sequence, which is 15.8–24.2% divergent from other species of the family Channidae. Morphological modifications usually associated with a subterranean life, such as reduction of eyes and enhancement of non-visual senses (taste, smell, mechanosensory systems) are absent in A. gollum. However, it shares with subterranean fishes a slight reduction of its pigmentation in comparison to epigean channids.


2019 ◽  
Vol 08 (04) ◽  
pp. 218-221
Author(s):  
Brett LaBrecque ◽  
Marioxy Contreras ◽  
Jessica Giordano ◽  
Elvira Parravicini

AbstractThe first known documented case of monochorionic–diamniotic twins with Coffin–Siris syndrome is described in this study. This case is notable because of the phenotypic differences between infants despite having identical genomes and causative variants. Also unique to this case is the clinical influence of early diagnosis using precision medicine techniques.


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