Cichlidae

Melanochromis labrosus is the only one of the 800 or so endemic cichlid species in Lake Malawi whose placement with mbuna or non-mbuna has been disputed on morphological grounds. Here, we redescribe M. labrosus using all obtainable specimens collected since its original description. In addition, we extensively survey vertebral counts in the mbuna. To determine if M. labrosus belongs with the mbuna, we review the morphological traits often
considered to define the mbuna as a natural group, concluding that none is a uniquely shared specialization. Two features of body coloration (a relatively small number of ocellate spots in the anal fin and a possible polychromatism in one population) suggest that M. labrosus is best considered a species of mbuna. Although its placement within the mbuna group remains somewhat equivocal, we unambiguously demonstrate that M. labrosus is not a
Melanochromis, since it lacks the synapomorphic striped color pattern typical of that genus. Melanochromis labrosus also does not fit within any other described genus. Therefore, we designate it the type species of Abactochromis, new genus. Abactochromis is unique in the mbuna in having greatly enlarged, lobate lips and several other autapomorphies. Contrary to published opinion, the hypertrophied lips of A. labrosus express high densities of taste
buds. We review the little that is known about the biology of A. labrosus and emphasize its noteworthy distribution within Lake Malawi, on rocky shores lakewide excepting the southern arms. We underscore the importance of including this problematic, and therefore potentially informative, species in future evolutionary genetic and genomic studies of the Lake Malawi cichlid species flock. Finally, we provide a key to the now thirteen genera of mbuna inhabiting Lake Malawi.

Se presenta un inventario actualizado de la familia Cichlidae para Bolivia, con base en la revisión taxonómica de la Colección Ictiológica UMSS - Museo Alcide d’Orbigny (Cochabamba-Bolivia) y registros bibliográficos. Se registraron 74 especies pertenecientes a 20 géneros, siendo Apistogramma (20 especies) y Crenicichla (16) los más diversos. Se adicionan cuatro registros para Bolivia. La cuenca Amazónica presentó 67 especies y la cuenca de La Plata 18. Dos especies fueron identificadas como introducidas y tres especies como posiblemente endémicas.

The cichlids of Africa present many challenges to the taxonomist. Diverse systematic problems at three levels in cichlid phylogeny form the subject matter of this dissertation. At the most general level, I summarize current morphological evidence that supports cichlid monophyly and the most-inclusive groups of cichlids. With this review as a framework, I argue that the most phylogenetically primitive African cichlid is Heterochromis multidens, a little-known large cichlid from the Zaire River basin. I redescribe this monotypic genus and species and illustrate much of its osteology. It possesses a distinctive suite of derived characters, but is uniquely primitive among African cichlids in infraorbital morphology and other features.

At a less inclusive phylogenetic level, I examine the controversy over the monophyletic status of the "species flock" of haplochromine cichlids in Lake Malawi. A derived type of anal-fin markings present in a subset of the Malawian fauna is shared with many non-Malawian haplochromines, indicating that the species flock of Lake Malawi is not monophyletic. The two (or more) faunal components of Lake Malawi are ecologically distinct.

The remaining major parts of the study are concerned with particular assemblages of haplochromine cichlids in Lake Malawi. I present a detailed phylogenetic analysis of the Cyrtocara livingstonii species-group of ambush predators, and characterize a new species in the group. I also describe three new species of haplochromines with three lateral spots and present a key to the three-spot assemblage. Intralacustrine dispersion of Malawi cichlids is briefly addressed in appended material.

Floating masses of vegetation are commonly seen in the southern region of Lake Malawi. These floating islands disperse littoral fishes across deep portions of the lake. Six islands were sampled and all yielded fishes. The 129 individuals collected belong to ten species, including one mormyrid, one cyprinid, two clariids, one cyprinodontid, four cichlids and one mastacembelid. Most of the species are characteristic of lakeshore swamps and are not endemic to Lake Malawi. Dispersal by floating islands may increase gene flow between disjunct populations of widespread species, particularly those inhabiting swamps. Such dispersal, theoretically, could also serve to establish founder populations of geographically isolated species.

ABSTRAK
Ikan louhan tergolong jenis ikan hibrid (sehingga tidak dapat ditentukan nama ilmiahnya) dari famili Cichlidae yang terindikasi sebagai ikan asing invasif di Danau Matano. Keberadaan ikan tersebut di Danau Matano perlu dikaji dan dikendalikan untuk menjaga kelestarian keanekaragaman hayati jenis ikan endemik. Penelitian ini bertujuan untuk menganalisis pola peremajaan dan laju eksploitasi ikan louhan sebagai pendekatan dalam pengendalian ikan asing invasif di Danau Matano, Sulawesi Selatan. Analisis data dilakukan terhadap 2.931 ekor ikan louhan yang ditangkap menggunakan jaring insang percobaan berbagai ukuran mata jaring dilengkapi data enumerator secara bulanan pada bulan Februari hingga November 2016 dengan bantuan perangkat lunak FiSAT II. Hasil analisis menunjukkan bahwa pola pertumbuhan ikan louhan di Danau Matano bersifat alometrik positif. Pertumbuhan mengikuti persamaan L t =23,67[1-e 0,41(t+0,4281) ]. Umur maksimum (t max) mencapai 7,32 tahun dengan performa pertumbuhan (Ø') sebesar 2,36. Laju mortalitas total (Z) tahunan didapatkan sebesar 1,46 tahun-1. Laju mortalitas penangkapan tahunan (F = 0,38 tahun-1) lebih rendah daripada laju mortalitas alami tahunan (M = 1,08 tahun-1). Laju eksploitasi (E) ikan louhan di Danau Matano hanya sebesar 0,26 tahun-1 dimana menunjukkan bahwa upaya pemanfaatannya masih sangat rendah. Pola peremajaan terjadi dua kali dalam setahun, yaitu pada Mei (16,19%) dan Oktober (6,05%). Upaya pengendalian ikan louhan sebagai ikan invasif di Danau Matano perlu dilakukan pada saat puncak peremajaan tertinggi secara berkesinambungan disertai peningkatan laju eksploitasi e " 48% dari upaya yang ada, terutama pada April-Mei dan September-Oktober di daerah litoral perairan danau.
Kata Kunci: Ikan asing invasif; ikan louhan; laju eksploitasi; pengendalian; pola peremajaan; Danau Matano

ABSTRACT
Flowerhorn cichlid is classified as hybrid species (so that the scientific name can't be determined) from Cichlidae which indicated as invasive alien fish in Lake Matano. The existence of flowerhorn in Lake Matano need to be assessed and controlled to preserve the biodiversity of endemic fish species. This research aims to assess recruitment pattern and utlization status of flowerhorn cichlid for controlling of invasive alien species at Lake Matano, South Sulawesi. Data analysis was carried out on 2,931 flowerhorn Cichlid caught using experimental gillnets of various mesh sizes included enumerators data which recorded monthly from February to November 2016 using FiSAT II software. The analysis resulted the growth pattern of flowerhorn cichlid in Matano louhan Lake was positive allometric. The growth equation of flowerhorn cichlid was Lt=23.67[1-e 0,4(t+0.4281) ]. Longevity (t max) attained 7.32 years with growth performance (Ø') was 2.36. The annual total mortality rate (Z) obtained 1.46 years-1. The annual fishing mortality rate (F = 0.38 years-1) is lower than the annual natural mortality rate (M = 1.08 years-1). Exploitation rate (E) of flowerhorn cichlid in Lake Matano only 0.26 years-1, which was indicated under exploitation. Recruitment pattern occurs twice a year, in May (16.19%) and October (6.05%). The eradication efforts to control population of flowerhorn cichlid as invasive alien species in Lake Matano needs to be done at the peak of recruitment and also increased exploitation rate about e” 48% of existing efforts, especially on April-May and September-October in the littoral area of Lake Matano.
Keywords: Invasive alien species; flowerhorn cichlid; exploitation rate; controlling; recruitment pattern; utilization status; Lake Matano

Penelitian tentang struktur ukuran dan faktor kondisi beberapa jenis ikan famili Cichlidae telah dilaksanakan di Waduk Djuanda Jawa Barat dari bulan Januari-Desember 2011. Sampel ikan diperoleh dari hasil tangkapan jaring insang dengan ukuran mata jaring 1; 1,5; 2; 2,5; 3; 3,5; dan 4 inci. Jaring dipasang sejajar garis pantai pada pukul 16.00 Wib, diangkat pada jam 06.00 Wib hari berikutnya. Jenis ikan yang diteliti diantaranya: Oscar (Amphilophus citrinelus), Golsom (Hemicromis elongatus) dan Nila (Oreochromis niloticus). Informasi mengenai struktur ukuran dan faktor kondisi tiga spesies ikan dari famili Cichlidae berguna untuk pengelolaan dan pemeliharaan keseimbangan biologi pada suatu ekosistem. Ukuran ikan yang tertangkap, oscar (9,5-11,4 cm), golsom (7,5-8,9 cm) dan nila (16-18,4 cm) . Nilai faktor kondisi ketiga jenis ikan berkisar antara 0,66-2,21, yang menandakan kondisinya baik.
Pendugaan periode reproduksi berdasarkan fluktuasi nilai faktor kondisi menjelaskan bahwa ketiga jenis ikan memiliki periode reproduksi yang berbeda. Perbandingan nilai berat relatif (Wr), A. citrinellus dan O. niloticus memiliki nilai Wr > 100 yang menyatakan bahwa ketersediaan pakan cukup melimpah dan kurangnya pesaing atau predator, sementara H. elongatus kondisinya terbagi dua diduga disebabkan oleh tekanan predator dan penangkapan yang terjadi pada saat umur muda.

Kata Kunci: Struktur ukuran, faktor kondisi, family cichlidae, Waduk Ir. H. Djuanda

Morphological differentiation among closely related species provides opportunities to study mechanisms shaping natural phenotypic variation. Here, we address variation in the orientation of melanin-colored body stripes in three cichlid species of the tribe Haplochromini. Melanochromis auratus displays a common pattern of dark, straight horizontal body stripes, whereas in Aristochromis christyi and Buccochromis rhoadesii, oblique stripes extend from the anterior dorsal to the posterior mid-lateral trunk. We first validated a stably reference gene, and then, investigated the chromatophore distribution in the skin by assessing the expression levels of the iridophore and melanophore marker genes, ltk and slc24a5, respectively, as well as pmel, a melanophore pigmentation marker gene. We found anterior-posterior differences in the expression levels of the three genes in the oblique-striped species. The higher anterior expression of ltk, indicates increased iridophore density in the anterior region, i.e., uneven horizontal distribution of iridophores, which coincides with the anterior dorsalization of melanophore stripe in these species. The obliqueness of the horizontal body stripes might be a result of distinct migratory or patterning abilities of melanophores in anterior and posterior stripe regions which could be reflected by variation in the expression of genes involved in melanophore patterning. To address this, we investigated anterior-posterior expression levels of a primary set of candidate target genes with known functions in melanophore migration and stripe patterning in the adult zebrafish, and their related gene regulatory network. Among these genes, those with differences in anterior-posterior expression showed only species-specific differential expression, e.g., sdf1a, col14a1a, ifitm5, and agpat3, with the exception of fbxw4/hagoromo (differentially expressed in an oblique-and the straight-striped species). In summary, distinct anterior-posterior gradients in iridophore density found to be more similar characteristic between the two oblique-striped species. Furthermore, the species-specific differential expression of genes involved in stripe patterning might also implicate distinct molecular processes underlying the obliqueness of body stripe in two closely related cichlid species. How to cite this article Ahi and Sefc (2017), Anterior-posterior gene expression differences in three Lake Malawi cichlid fishes with variation in body stripe orientation. PeerJ 5:e4080; DOI 10.7717/peerj.4080

The cichlids of Africa present many challenges to the taxonomist. Diverse systematic problems at three levels in cichlid phylogeny form the subject matter of this dissertation. At the most general level, I summarize current morphological evidence that supports cichlid monophyly and the most-inclusive groups of cichlids. With this review as a framework, I argue that the most phylogenetically primitive African cichlid is Heterochromis multidens, a little-known large cichlid from the Zaire River basin. I redescribe this monotypic genus and species and illustrate much of its osteology. It possesses a distinctive suite of derived characters, but is uniquely primitive among African cichlids in infraorbital morphology and other features.

At a less inclusive phylogenetic level, I examine the controversy over the monophyletic status of the "species flock" of haplochromine cichlids in Lake Malawi. A derived type of anal-fin markings present in a subset of the Malawian fauna is shared with many non-Malawian haplochromines, indicating that the species flock of Lake Malawi is not monophyletic. The two (or more) faunal components of Lake Malawi are ecologically distinct.

The remaining major parts of the study are concerned with particular assemblages of haplochromine cichlids in Lake Malawi. I present a detailed phylogenetic analysis of the Cyrtocara livingstonii species-group of ambush predators, and characterize a new species in the group. I also describe three new species of haplochromines with three lateral spots and present a key to the three-spot assemblage. Intralacustrine dispersion of Malawi cichlids is briefly addressed in appended material.

Modes and mechanisms of speciation are best studied in young species pairs. In older taxa, it is increasingly difficult to distinguish what happened during speciation from what happened after speciation. Lake Victoria cichlids in the genus Pundamilia encompass a complex of young species and polymorphic populations. One Pundamilia species pair, P. pundamilia and P. nyererei, is particularly well suited to study speciation because sympatric population pairs occur with different levels of phenotypic differentiation and reproductive isolation at different rocky islands within the lake. Genetic distances between allopatric island populations of the same nominal species often exceed those between the sympatric species. It thus remained unresolved whether spe-ciation into P. nyererei and P. pundamilia occurred once, followed by geographical range expansion and interspecific gene flow in local sympatry, or if the species pair arose repeatedly by parallel speciation. Here, we use genomic data and demographic modelling to test these alternative evolutionary scenarios. We demonstrate that gene flow plays a strong role in shaping the observed patterns of genetic similarity, including both gene flow between sympatric species and gene flow between allopatric populations , as well as recent and early gene flow. The best supported model for the origin of P. pundamilia and P. nyererei population pairs at two different islands is one where speciation happened twice, whereby the second speciation event follows shortly after introgression from an allopatric P. nyererei population that arose earlier. Our findings support the hypothesis that very similar species may arise repeatedly, potentially facilitated by introgressed genetic variation.

Hemitaeniochromis brachyrhynchus, an anatomically distinctive and apparently rare new cichlid, is described and illus-trated from specimens collected at two widely separated localities within Lake Malaŵi. It is easily distinguished from H.urotaenia, type species of the genus, by its narrow lacrimal bone which is only one-third of the orbit length, a characterthought to be unique not only in Hemitaeniochromis but among all known Lake Malaŵi cichlids. The genus Hemitaenio-chromis Eccles & Trewavas (1989) is redefined to allow provisional inclusion of this new species. Two species placed inProtomelas by Eccles & Trewavas (1989) [P. insignis (Trewavas) and P. spilopterus (Trewavas)] were recently transferredto Hemitaeniochromis by some authors, without much evidence. The generic placement of these controversial taxa, and of several undescribed species known only from underwater photographs, is briefly reconsidered.

The cichlid fish Green Chromide Etroplus suratensis (Bloch) is an economically valuable food fish and a preferred candidate for brackishwater aquaculture in India. Genetic variation of E. suratensis collected from 11 different geographic locations of Kerala state, India was investigated using microsatellite and mitochondrial DNA markers (cytochrome c oxidase 1 (CO1) and 16S rDNA genes).  Seventeen primers published for two cichlid species were tested to amplify homologous microsatellite loci in E. suratensis. Six primers yielded successful amplification and only one was found to be polymorphic. Microsatellite analysis revealed a low genetic variation with alleles ranging from 1 to 4. The observed heterozygosity and expected heterozygosity ranged from 0.000 to 0.167 and 0.000 to 0.104. The results showed relatively lower variation in Kayamkulam and Vembanad lake populations. Mitochondrial DNA (CO1) analysis revealed 9 haplotypes with very low haplotype and nucleotide diversity. Genetic differentiation by pairwise FST showed that samples from Chandragiripuzha estuary are significantly different from all other populations. AMOVA analysis of both markers indicates significant differentiation between populations. The results of the two markers suggest that the studied 11 populations of E. suratensis showed low genetic variation between populations and leads to the conclusion that they are drawn from the same randomly mating gene pool.

Monthly data of length composition for Tylochromis jentinki (Steindachner, 1895), landed between February 2004 and January 2006 in Ebrié Lagoon (Ivory Coast) were used to estimate the growth, mortality and exploitation parameters of the stock. A total of 1850 individuals ranging from 7.5 to 23.5 cm SL (standard length), were examined. Length frequency data were analyzed with FiSAT software using the ELEFAN 1 package to estimate the population parameters. We estimated von Bertalanffy growth parameters: L∞ = 25.00 cm, K = 0.67 year-1, and t0 = -0.28 year-1, with the growth performance index, φ’ of 2.62. The length-weight relationship was W = 0.0215 x SL2.98 and described isometric growth for the species with an asymptotic weight (W∞) = 314.99 g. Total mortality (Z) estimated from catch-curve analyses was = 2.38 year-1. Natural mortality based on growth parameters and mean environmental temperature (T = 28ºC) was M = 1.45 year-1. Furthermore, the fishing mortality rate of 0.93 year-1 was by far in excess of the precautionary target (Fopt = 0.73 year-1) and slightly under the limit (Flimit = 0.97 year-1) biological reference points. With this level of mortality and exploitation level (E = 0.39 < 0.50), the stock was under-exploited.

Представлены результаты исследования влияния присутствия модельного хищника на заботу о потомстве у чернополосой цихлазомы Amatitlania nigrofasciata. Рассмотрены основные различия в родительских функциях самца и самки в семейной группе и их трансформация при наличии потенциальной угрозы для кладки и выводка. Проанализирована динамика родительского поведения на протяжении всего периода заботы о потомстве и влияние на эту динамику присутствия хищника. Показано, что присутствие хищника оказывает сложное трансформирующее влияние на всю структуру родительского поведения в семейной группе чернополосой цихлазомы. При этом наибольшей лабильностью отличается поведение самца в период после перехода молоди к свободному плаванию.

The importance of species recognition to taxonomic diversity among Lake Malawi cichlids has been frequently discussed. Hybridization — the apparent breakdown of species recognition — has been observed sporadically among cichlids and has been viewed as both a constructive and a destructive force with respect to species diversity. Here we provide genetic evidence of a natural hybrid cichlid population with a unique colour phenotype and elevated levels of genetic variation. We discuss the potential evolutionary consequences of interspecific hybridization in Lake Malawi cichlids and propose that the role of hybridization in generating both genetic variability and species diversity of Lake Malawi cichlids warrants further consideration.

A downward kink one or more scales in length at the posterior end of the upper lateral line, leaving only one scale row instead of two between it and the lower lateral line, has been considered a synapomorphy uniting as a monophyletic group all members of both clades of endemic haplochromine cichlids of Lake Malawi. Here, this claim is tested by surveying the character in representatives of all genera of Lake Malawi haplochromines (tribe Haplochromini of the subfamily Pseudocrenilabrinae). Presence of the kink is shown to be variable in most genera, and it was not documented at all in two (Abactochromis, Cyrtocara). Specimens with no kink occur in many genera, and kink presence and length frequently vary on the two sides of the body. Thus, it is difficult to justify the kink as a synapomorphy of the species flock. The two clades differ in kink frequency; a kink occurred on at least one side of the body in 79% of bilaterally assessable specimens in the non-mbuna clade, but in only 53% of those in the mbuna clade (p < 0.0001). When a kink is present, its length is more variable in non-mbuna (1 to 8 scales, mode 2) than mbuna (1 to 4 scales, mode 1). Extension of the upper lateral line backward from the upper flank close to or onto the caudal peduncle, where no scale row is as dorsally situated, is identified as one cause of kink existence; additional factors likely await discovery. Contrary to published statements, the kink is expressed in some specimens of Astatotilapia calliptera, a phylogenetically important nonendemic haplochromine found in Lake Malawi and elsewhere, which may be the sister of the lake's endemic flock. An apparently identical lateral-line kink occurs sporadically in haplochromines in other lakes and in members of three other pseudocrenilabrine cichlid tribes, further refuting the hypothesis that this character is a synapomorphy of the Lake Malawi species flock.

The cichlid fish, Green Chromide [Etroplus suratensis (Bloch)] is an economically valuable food fish and a preferred candidate for brackishwater aquaculture in India. Genetic variation of E. suratensis collected from 11 different geographic locations of Kerala state, India was investigated using microsatellite and mitochondrial DNA markers [cytochrome c oxidase 1 (CO1) and 16S rDNA genes]. Seventeen primers published for two cichlid species were tested to amplify homologous microsatellite loci in E. suratensis. Six primers yielded successful amplification and only one was found to be polymorphic. Microsatellite analysis revealed a low genetic variation with alleles ranging from 1 to 4. The observed heterozygosity and expected heterozygosity ranged from 0.000 to 0.167 and 0.000 to 0.104. The results showed relatively lower variation in Kayamkulam and Vembanad lake populations. Mitochondrial DNA (CO1) analysis revealed 9 haplotypes with very low haplotype and nucleotide diversity. Gen...

A mouthbrooding cichlid which produced offspring of its own? Is that possible? Obviously it is possible because I and my colleagues just published a report on a hybrid Lake Victoria cichlid held in isolation which spawned with itself and produced offspring. Our
detailed analyses showed that she reproduced by self-fertilization or ‘selfing’ as it usually is called among scientists.

Banded jewel cichlid (Hemichromis elongatus, Guichenot 1861) is unintentional introduced fish in Cirata Reservoir. These fish populations have significant increased in the last five years. The objective of this research were to analyze reproductive biological aspects of banded jewel cichlid such as sex ratio, spawning season, length at first maturity, fecundity and distribution of egg diameter. Research was conducted in March, May, July and September 2011. Experimental gillnet segregated into seven different mesh size were used for fish sampling. Banded jewel cichlid samples observed were 316 fishes with sex ratio of 1:1.20. Sex ratio indicated balanced conditions. The fish spawned more than once a year with peak spawning period was occurred at dry seasons, from March until July. Total length at first maturity of banded jewel male was 11.3 cm (range of 10.5 to 12.2 cm), while for the female it was 10.7 cm (range of 10.1 to 11.5 cm). Fecundity of this fish in the ranged of 511 to 4,900 eggs (average of 2,131 eggs), with eggs diameter in the range of 0.28 to 1.58 mm indicating that banded jewel was categorized as partial spawner fish.

KEYWORDS: Reproductive, banded jewel cichlid, Hemichromis elongatus, Cirata Reservoir

Hemitaeniochromis brachyrhynchus, an anatomically distinctive and apparently rare new cichlid, is described and illustrated
from specimens collected at two widely separated localities within Lake Malaŵi. It is easily distinguished from H. urotaenia, type species of the genus, by its narrow lacrimal bone which is only one-third of the orbit length, a character thought to be unique not only in Hemitaeniochromis but among all known Lake Malaŵi cichlids. The genus Hemitaeniochromis Eccles & Trewavas (1989) is redefined to allow provisional inclusion of this new species. Two species placed in Protomelas by Eccles & Trewavas (1989) [P. insignis (Trewavas) and P. spilopterus (Trewavas)] were recently transferred to Hemitaeniochromis by some authors, without much evidence. The generic placement of these controversial taxa, and
of several undescribed species known only from underwater photographs, is briefly reconsidered.

The diversity of fin morphology within and across fish taxa offers great, but still largely unexplored, opportunities to investigate the proximate mechanisms underlying fin shape variation. Relying on available genetic knowledge brought forth mainly by the comprehensive study of the zebrafish caudal fin, we explored candidate molecular mechanisms for the maintenance and formation of the conspicuously elongated filaments adorning the unpaired fins of the East African " princess cichlid " Neolamprologus brichardi. Via qPCR assays, we detected expression differences of candidate genes between elongated and short regions of intact and regenerating fins. The identified genes include skeletogenic and growth factors (igf2b, fgf3, bmp2 and bmp4), components of the WNT pathway (lef1, wnt5b and wnt10) and a regulatory network determining fin ray segment size and junction (cx43, esco2 and sema3d), as well as other genes with different roles (mmp9, msxb and pea3). Interestingly, some of these genes showed fin specific expression differences which are often neglected in studies of model fish that focus on the caudal fin. Moreover, while the observed expression patterns were generally consistent with zebrafish results, we also detected deviating expression correlations and gene functions. The phenotypic diversity of fish is outstanding among vertebrates. One part of this immense diversity is variation in fin shape, which often distinguishes even closely related species (e.g. Xiphophorus platyfish and swordtails, Bodianus lipfish, various gourami and cichlid genera). Although fin shape is connected with swimming performance 1 , fins also serve important signal functions in competitive and sexual interactions. Both courtship and aggressive displays typically involve the presentation of erected fins, and the importance of fin shape in mate choice and male-male competition 2–4 suggests that various selection pressures play a role in fin shape diversification. The developmental mechanisms regulating fin growth and shape have mainly been studied in the zebrafish caudal fin 5. The capability of fish to fully regenerate amputated fins makes them an ideal model in regeneration biology, not least because of the high degree of conservation in developmental patterning between fish fins and the appendages of other vertebrates 5–7. The teleost fin is supported by segmented fin rays, which consist of an inner core of mesenchymal cells, vessels and nerves, shielded by bone (hemirays) and covered with epithelium. The fin rays grow by the addition of bony segments at their distal end, and altered regulation of fin ray growth, including cellular proliferation, differentiation and survival, can be an important source of fin shape variation 8. Regeneration studies showed that after amputation, regeneration of the fin tissue is initiated by the establishment of highly proliferative tissue (blastema) immediately distal to each truncated fin ray. The blastema continues to elongate at the distal edge while the proximal part of the new tissue re-differentiates into the mature fin structures until the original size is restored 5,9. At the molecular level, components of various developmental pathways, such as WNT, FGF, Hedgehog and retinoic acid (RA) signalling, as well as epigenetic, skeletogenic and structural remodelling factors have been identified to orchestrate both ontogenetic and regenerative fin growth 8–10. Recently, candidate effectors (gene products and metabolites) of positional memory, a prerequisite for the regeneration of the proper appendage size and pattern, were described in the zebrafish caudal fin 11. Contrasting with the extensive work in fish models (mainly zebrafish), little use has so far been made of the natural diversity among fishes 12–14. The resources created in zebrafish open countless possibilities to investigate genes, regulatory networks, signalling cascades, etc., for their role in fin shape diversification and to test for

Melanochromis labrosus is the only one of the 800 or so endemic cichlid species in Lake Malawi whose placement with mbuna or non-mbuna has been disputed on morphological grounds. Here, we redescribe M. labrosus using all obtainable specimens collected since its original description. In addition, we extensively survey vertebral counts in the mbuna. To determine if M. labrosus belongs with the mbuna, we review the morphological traits often considered to define the mbuna as a natural group, concluding that none is a uniquely shared specialization. Two features of body coloration (a relatively small number of ocellate spots in the anal fin and a possible polychromatism in one population) suggest that M. labrosus is best considered a species of mbuna. Although its placement within the mbuna group remains somewhat equivocal, we unambiguously demonstrate that M. labrosus is not a Melanochromis, since it lacks the synapomorphic striped color pattern typical of that genus. Melanochromis lab...

Определен и описан новый для ихтиофауны России аллохтонный вид – восьмиполосая цихлазома Rocio octofasciata (Regan, 1903), населяющий оз. Старая Кубань, г. Краснодар. Проведено сравнение условий жизни данного вида в различных регионах: в историческом ареале, в водоемах юга США и в оз. Старая Кубань. Сформулировано предположение, согласно которому вид образовал в озере самовоспроизводящуюся популяцию и полностью натурализовался. Предложены дальнейшие направления исследования популяции этого вида в Старой Кубани.

During the development of the vertebrate feeding apparatus, a variety of complicated cellular and molecular processes participate in the formation and integration of individual skeletal elements. The molecular mechanisms regulating the formation of skeletal primordia and their development into specific morphological structures are tightly controlled by a set of interconnected signalling pathways. Some of these pathways, such as Bmp, Hedgehog, Notch and Wnt, are long known for their pivotal roles in craniofacial skeletogenesis. Studies addressing the functional details of their components and downstream targets, the mechanisms of their interactions with other signals as well as their potential roles in adaptive morphological divergence, are currently attracting considerable attention. An increasing number of signalling pathways that had previously been described in different biological contexts have been shown to be important in the regulation of jaw skeletal development and morphogenesis. In this review, I provide an overview of signalling pathways involved in trophic skeletogenesis emphasizing studies of the most species-rich group of vertebrates, the teleost fish, which through their evolutionary history have undergone repeated episodes of spectacular trophic diversification.

Приведены результаты биоанализа нового для ихтиофауны России чужеродного вида – восьмиполосой цихлазомы (Rocio octofasciata). Указаны основные меристические признаки рыб и их окраска. Приведены первые данные по питанию цихлазом в озере Старая Кубань и значения ряда важнейших морфофункциональных характеристик исследованных рыб. Обсуждены перспективы существования натурализовавшейся популяции восьмиполосой цихлазомы в озере Старая Кубань и основные направления дальнейших исследований.

Background The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC end sequences and ESTs, but comparative genome analysis and maps of quantitative trait loci (QTL) are still limited. Results We have constructed a high-resolution radiation hybrid (RH) panel for the Nile tilapia and genotyped 1358 markers consisting of 850 genes, 82 markers corresponding to BAC end sequences, 154 microsatellites and 272 single nucleotide polymorphisms (SNPs). From these, 1296 markers could be associated in 81 RH groups, while 62 were not linked. The total size of the RH map is 34,...

Feeding is a complex behaviour comprised of satiety control, foraging, ingestion and subsequent digestion. Cichlids from the East African Great Lakes are renowned for their diverse trophic specializations, largely predicated on highly variable jaw morphologies. Thus, most research has focused on dissecting the genetic, morphological and regulatory basis of jaw and teeth development in these species. Here for the first time we explore another aspect of feeding, the regulation of appetite related genes that are expressed in the brain and control satiety in cichlid fishes. Using qPCR analysis, we first validate stably expressed reference genes in the brain of six haplochromine cichlid species at the end of larval development prior to foraging. We next evaluate the expression of 16 appetite related genes in herbivorous and carnivorous species from the parallel radiations of Lake Tanganyika, Malawi and Victoria. Interestingly, we find increased expression of two appetite-regulating genes (anorexigenic genes), cart and npy2r, in the brain of carnivorous species in all the three lakes. This supports the notion that appetite gene regulation might play a part in determining trophic niche specialization in divergent cichlid species, already prior to exposure to different diets. Our study contributes to the limited body of knowledge on the neurological circuitry that controls feeding transitions and adaptations in cichlids and other teleosts.