Dorsal Fin Spines Research Articles

Precision of Three Structures for Saugeye Age Estimation

AbstractWe evaluated the precision of age estimates obtained from sagittal otoliths, scales, and dorsal fin spines from 341 saugeyes (Walleye Sander vitreus × Sauger S. canadensis) collected from six Kansas reservoirs. Between‐reader agreement was greatest for otoliths, followed by dorsal spines and then scales. Coefficient of variation (CV) values for between‐reader comparisons were 1.3–3.1% for otoliths and 13.8–18.2% for dorsal spines. Between‐reader comparisons for scales were the most variable, with CV estimates between 19.9% and 23.1%. Age estimates from otoliths aligned with age estimates from scales more often than with estimates from dorsal spines, although age estimate comparisons between structures were generally variable. Between‐reader agreement for scales and dorsal spines decreased with increasing estimated age; however, agreement for otoliths generally remained high (i.e., >80%) through age 10. Given greater precision relative to other structures, we recommend the use of sectioned otoliths to estimate ages of saugeyes, especially when sacrificing the fish is not a concern.

A New Record of the Pseudolaguvia nubila (Siluriformes: Erethistidae) from Baandhkhola (Stream) in Central Nepal

In this study, we describe a miniature sisorid catfish of the family Erethistidae, as a new distributional record of Pseudolaguvia nubila from the Baandhkhola (stream), a tributary of Narayani River inCentral Nepal. Pseudolaguvia nubila shows its distribution to Nepal is distinguished from its congeners by combination of characters, such as- two broad and distinct yellowish vertical bands at the origin of dorsal fin and anal fin, smooth outer edge of the dorsal fin spine, dorsal fin spine length 13.23-17.60 % SL, pectoral fin length 24.89-26.27 % SL, pectoral fin spine length 18.39-19.48 % SL and body depth at anus 17.22-18.69 % SL.Int. J. Appl. Sci. Biotechnol. Vol 5(4): 434-441

Chelidoperca tosaensis, a new species of perchlet (Serranidae) from Japan and the Philippines, with geographic range extension of C. stella to the northwestern Pacific Ocean

Chelidoperca tosaensis is described as a new species based on 84 specimens from Japan and the Philippines taken from depths of 60–302 m. The species can be distinguished from all known congeners by having the following combination of characters: scale rows between lateral line and base of spinous dorsal fin 3; pored lateral-line scales 37–42 (modally 39); scale rows in longitudinal series 39–43 (modally 40); no longitudinal dark stripe or row of dark blotches on body side. The new species is additionally characterized by having a combination of numerous, scattered, yellow spots on dorsal and anal fins with red streak or cluster of reddish spots over bases of about 4–6th dorsal-fin spines; large ocellated red spot with pinkish white border present on membrane between opercular spines; pelvic fin with middle area yellow with whitish spine, and whitish first, second and fifth soft rays; caudal fin with about three transverse rows of yellow spots centrally and posteriorly, two fan-shaped rows of red blotches on basal third, and a pair of white blotches with a pair of yellow blotches between white blotches on the base. Diagnostic characters of Chelidoperca stella, previously known only from its type locality in the Andaman Sea, are updated based on 12 specimens from Taiwan, the Gulf of Tonkin, Vietnam and the Philippines. These specimens represent the first records of the species from the Pacific Ocean.

The “Lembeh Frogfish” Identified: Redescription of Nudiantennarius subteres (Smith and Radcliffe, in ) (Teleostei: Lophiiformes: Antennariidae)

The “Lembeh Frogfish” or “Ocellated Frogfish,” a distinct antennariid, known for many years, especially among members of the dive community, and suggested by some to represent an undescribed species, is identified as Nudiantennarius subteres (Smith and Radcliffe). Unique in several ways—including reduced dermal spinules, the body appearing naked; illicium short, about half the length of the second dorsal-fin spine; second dorsal-fin spine unusually long and narrow, without a posterior membrane; pectoral lobe narrow, somewhat detached from the body; membranes between the rays of the paired fins deeply incised; and all pelvic-fin rays simple—the species is redescribed and figured below. Morphological and molecular analyses indicate a close relationship with the Sargassumfish, Histrio histrio.

Review of the Chromis xanthura species group (Perciformes: Pomacentridae), with description of a new species

A taxonomic review of the Chromis xanthura species group, defined here as having 13 dorsal-fin spines, three upper and three lower procurrent caudal-fin rays, two black bands at the preopercular and opercular margins, and a yellow caudal fin when juvenile, resulted in the recognition of three species, Chromis xanthura (Bleeker 1854), Chromis opercularis (Gunther 1867), and Chromis anadema sp. nov. Chromis xanthura and C. opercularis, the Pacific and Indian Ocean paired sister species, respectively, are redescribed, with confirmation of two color types of C. xanthura (having a white or black caudal peduncle and fin) as a single species on the basis of morphological and molecular analyses. Chromis anadema sp. nov., described from the oceanic islands of the Pacific Ocean on the basis of 21 specimens, is characterized by having 28–33 gill rakers; longest dorsal-fin soft ray length 20.0–24.7% of standard length (SL); first anal-fin spine length 5.0–6.1% of SL; caudal-fin length 33.4–43.8% of SL; posterior tips of caudal-fin lobes not filamentous in adults; broad black bands along preopercular and opercular margins, sum width of two bands 28.9–38.7% of head length; distal half of soft-rayed portion of dorsal fin transparent in adults; triangular black blotches at upper and lower caudal-fin base in adults; caudal peduncle and fin bluish black in adults; and body grayish, and all fins (except for pectoral fin) bright yellow in juveniles.

Ostichthys spiniger, a new species of soldierfish from New Ireland, Papua New Guinea, western Pacific Ocean (Teleostei: Holocentridae)

A new species of soldierfish, Ostichthys spiniger, from off northern New Ireland, Papua New Guinea, is described on the basis of a single specimen collected with a trawl at 180-181 m depth near Kavieng. The new species is characterised by the following characters: scales above lateral line to mid-base of spinous portion of dorsal fin 31/2; no half-scale present anterior to first lateral-line scale; dorsal profile of head nearly uniformly convex; anterior end of each nasal bone with a sharp, forwardly directed spine; a strong spine at the corner of preopercle, which is significantly larger than other serrations; pectoral-fin rays 17; lateral-line scales 29; gill rakers 8 + 13; last dorsal-fin spine shorter than penultimate spine; body depth 2.2 in SL; HL 2.4 in SL; snout very short, 6.6 in HL; least depth of caudal peduncle 4.9 in HL. The new species is compared with other species in the genus. A revised key to the species of Ostichthys is presented. The new species is most similar to O. acanthorhinus.

Occurrence of Middle Miocene Fossil Cyprinid Fish in the Northern Qaidam Basin and its Paleoenvironmental Implications

AbstractWith a thick sequence of early Eocene to Pleistocene terrestrial records, the Qaidam Basin on the northern Tibetan Plateau provides an important sedimentary archive for understanding the paleoenvironmental evolution of the northeast Tibetan Plateau. In this study, specimens of fossil fish remains are collected from the late Middle Miocene (Serravallian, ∼12Ma) of the middle member of the Shang Youshashan Formation, Dahonggou (DHG) section, in the northern Qaidam Basin. Based on a systematic study of these materials, the remains have assigned to Cyprinidae, with typical pharyngeal teeth and dorsal fin spines with serrations on the posterior edge. Our discovery improves understanding of the cyprinid fish distribution characteristics in the Qaidam Basin during the Cenozoic. Cooccurrences of terrestrial brackish ostracod species Cyprideis and long chain alkenonesin the layer indicate that the studied cyprinid fish lived in a generally large brackish to saline water body during the late middle Miocene (Serravallian), when the climate of Qaidam Basin was still not sufficiently dry to form an extreme saline water lake.

First record of elasmobranchs from the Lower Cretaceous of Argentina (Neuquén Basin)

The material reported herein comes from the Lower Cretaceous Agrio Formation (Neuquén Basin, west-central Argentina). These fishes dwelled in a Pacific Ocean embayment in southwestern Gondwana before the establishment of the Andean Cordillera. The material consists of an incomplete dorsal fin spine of the widespread Hybodontoidea clade (from upper Valanginian beds) and a partial tooth of one of the earliest known lamniforms (from upper Hauterivian beds).

Two new goatfishes of the genus Upeneus (Mullidae) from Australia and Indonesia

Two new goatfishes of the genus Upeneus (Mullidae) belonging to the putative japonicus species group are described and compared with congeneric species using a large set of meristic, morphometric and colour characters. Upeneus farnis n. sp. Uiblein & Peristiwady is described based on 14 adult specimens (> 65 mm SL) collected at the local fish market of Bitung, NE Sulawesi, Indonesia. Upeneus spottocaudalis n. sp. Uiblein & Gledhill is described based on 16 adult and seven subadult specimens (< 65 mm SL) specimens collected by trawling surveys off NE Australia and one non-type adult specimen collected off southern Indonesia. The new species differ from all other congenerics in the combination of dorsal-fin spine, pectoral-fin ray and gill raker numbers, body and head depth, length of head, snout, barbels and paired fins, height of anal and dorsal fins, eye size, and body, barbel and caudal-fin colour patterns. When compared in detail with the 12 other species of the japonicus group, Upeneus farnis n. sp. can be distinguished by smaller eyes, shallower anal and second dorsal fins, more pectoral-fin rays and gill rakers, and the lower caudal-fin lobe almost completely dark pigmented. Upeneus spottocaudalis n. sp. differs from the other japonicus-group species in larger eyes, higher second dorsal fin, pectoral fin shorter than pelvic fin, and presence of rounded, dark spots on the lower caudal-fin lobe. Subadults differ from adult U. spottocaudalis n. sp. mainly in longer pelvic fins. The high diversity of Upeneus species in relation to divergence in colour patterns and the need of further taxonomic exploration of the genus Upeneus is discussed.

Are Pacific spiny dogfish lying about their age? A comparison of ageing structures for Squalus suckleyi

Historically, Pacific spiny dogfish (Squalus suckleyi) have been aged using dorsal fin spines, a method that was validated through bomb radiocarbon analysis and oxytetracycline tagging. However, ages generated using this method generally have poor precision and require estimation of missing growth bands in eroded spines, prompting a search for improved age determination methods. In the present study, spiny dogfish were aged using the historical spine method and a new method involving stained thin sections of vertebral centra. Results of an inter-laboratory exchange demonstrated the need for readers to calibrate ageing criteria with a reference collection before reading structures, a practice that yielded significant improvements in between-reader precision of spine band pair counts. After calibration, the primary readers examined the full sample set. The two structures yielded similar age estimates for younger animals, but centrum estimates were consistently younger than spine estimates after age-10. Although further work is necessary to fully explore potential reasons for the observed bias, such as centrum size and location within the vertebral column, at the present time centra are not a suitable alternative to dorsal fin spines for age determination of Pacific spiny dogfish >10 years of age.

Morphological and molecular divergence between Crenidens crenidens (Forsskål, 1775) and C. indicus Day, 1873 (Perciformes: Sparidae) and notes on a Red Sea endemic lineage of C. crenidens

Additional data, resulting from examination of newly collected material from the Red Sea, east coast of Africa, Arabian Gulf, Pakistan, and western coast of India, and a phylogenetic analysis of the COI barcoding region, confirms Crenidens crenidens (Forsskal) and C. indicus Day as valid species. The latter species was earlier regarded as a subspecies of C. crenidens. In addition, the analyses herein show that specimens from the Red Sea form a distinct monophyletic sub-clade within C. crenidens, characterized by low genetic divergence from specimens from the southwestern Indian Ocean. Close comparison of 34 morphological characters showed that specimens from South Africa and Mozambique differ from Red Sea specimens only in having slightly longer pelvic fins [4.6–4.9 in standard length (SL) vs. 4.8–6.1 in SL]. Examination of additional specimens of both species provided more assessment of inter- and intraspecific variation in meristic and morphometric characters. A new set of characters that help to distinguish C. indicus from C. crenidens is proposed: the former species has a deeper body and caudal peduncle; more scales between fifth dorsal-fin spine and lateral line; scales on top of head extending forward to vertical through posterior margin of pupil; longer pelvic fins; lips with tiny cirri; caudal fin blackish distally; and usually with obvious black spot at pectoral-fin axil. Crenidens indicus was previously reported from central Oman, Arabian Gulf, to Pakistan; herein its presence from the western coast of India, Gujarat and Mumbai (= Bombay), is confirmed. Descriptions of C. crenidens and C. indicus based on material examined, photographs of alive and fresh fishes and an updated key to the three known species of Crenidens are provided.

Remora cranial vein morphology and its functional implications for attachment

Remora fishes adhere to, and maintain long-term, reversible attachment with, surfaces of varying roughness and compliance under wetted high-shear conditions using an adhesive disc that evolved from the dorsal fin spines typical of other fishes. Evolution of this complex hierarchical structure required extensive reorganization of the skull and fin spines, but the functional role of the soft tissues of the disc are poorly understood. Here I show that remora cranial veins are highly-modified in comparison to those of other vertebrates; they are transposed anteriorly and enlarged, and lie directly ventral to the disc on the dorsum of the cranium. Ancestrally, these veins lie inside the neurocranium, in the dura ventral to the brain, and return blood from the eyes, nares, and brain to the heart. Repositioning of these vessels to lie in contact with the ventral surface of the disc lamellae implies functional importance associated with the adhesive mechanism. The position of the anterior cardinal sinus suggests that it may aid in pressurization equilibrium during attachment by acting as a hydraulic differential.

Hypostomus sertanejo (Siluriformes: Loricariidae), new armoured catfish species from north-eastern Brazil.

A re-evaluation of the armoured catfish species of Hypostomus in the Rio Jaguaribe, north-eastern Brazil, was prompted by the discovery of specimens with pale spots on a dark background collected from that basin c. 1936 and deposited at the Academy of Natural Sciences of Philadelphia. Recent field collections in the Rio Jarguaribe basin confirmed the presence of the pale-spotted specimens and its distinctiveness as a new species. Hypostomus sertanejo n. sp. is diagnosed from other species of Hypostomus by having fins and dermal-plated regions of head and body with pale spots or vermiculations on darker background, teeth slender, asymmetrically bicuspid and numerous (34-75) on dentary and premaxilla, depressed dorsal-fin spine not reaching adipose spine, unbranched pectoral-fin spine longer than unbranched pelvic-fin ray, seven branched dorsal-fin rays and one (rarely two) predorsal plate(s) bordering supraoccipital. Ancistrus salgadae Fowler 1941 is hypothesized to be a junior synonym of Hypostomus carvalhoi (Miranda-Ribeiro, 1937), a dark-spotted Hypostomus described from the Rio Granjeiro, a tributary to the upper Rio Salgado.

Precision and Accuracy of Age Estimates Obtained from Anal Fin Spines, Dorsal Fin Spines, and Sagittal Otoliths for Known-Age Largemouth Bass

Sagittal otoliths are the preferred aging structure for Micropterus spp. (black basses) in North America because of the accurate and precise results produced. Typically, fisheries managers are hesitant to use lethal aging techniques (e.g., otoliths) to age rare species, trophy-size fish, or when sampling in small impoundments where populations are small. Therefore, we sought to evaluate the precision and accuracy of 2 non-lethal aging structures (i.e., anal fin spines, dorsal fin spines) in comparison to that of sagittal otoliths from known-age Micropterus salmoides (Largemouth Bass; n = 87) collected from the Ocmulgee Public Fishing Area, GA. Sagittal otoliths exhibited the highest concordance with true ages of all structures evaluated (coefficient of variation = 1.2; percent agreement = 91.9). Similarly, the low coefficient of variation (0.0) and high between-reader agreement (100%) indicate that age estimates obtained from sagittal otoliths were the most precise. Relatively high agreement between readers for anal fin spines (84%) and dorsal fin spines (81%) suggested the structures were relatively precise. However, age estimates from anal fin spines and dorsal fin spines exhibited low concordance with true ages. Although use of sagittal otoliths is a lethal technique, this method will likely remain the standard for aging Largemouth Bass and other similar black bass species.

Discovery of the oldest Gobius (Teleostei, Gobiiformes) from a marine ecosystem of Early Miocene age

Gobiidae (Gobiiformes, Teleostei) is among the largest families of vertebrates. These fishes are distributed worldwide and contribute significantly to species diversity in marine habitats and reefs. However, their fossil record is sparse prior to the Miocene and little is known about the course of diversification of the clade. Here we report exceptionally well-preserved skeletal remains of the oldest known Gobius from an Early Miocene (Burdigalian) marine ecosystem of Central Europe (Czech Republic). Gobius jarosi Přikryl & Reichenbacher sp. nov. is dated to 19.1–20.4 Ma by biostratigraphical analysis of calcareous nannoplankton from small fragments of the holotype matrix. Gobius jarosi sp. nov. is characterized by a pterygiophore formula of 3-22110 and a premaxilla with a distinctive postmaxillary process, has 11 abdominal and 16–17 caudal vertebrae, six thin spines in the first dorsal fin and one spine and 12 soft rays in the second dorsal fin, one spine and 11 rays in the anal fin, and two anal fin pterygiophores preceding the first haemal spine. Large ctenoid scales cover the body except for its anterior portion and the head. A comparative analysis of meristic and osteological data suggests close affinities between G. jarosi sp. nov. and the extant species G. niger, G. roulei and G. vittatus. Accompanying fish fossils and nannoplankton assemblages indicate that G. jarosi sp. nov., like G. roulei and G. vittatus, lived in an inshore to offshore marine ecosystem. The discovery of such an early member of the lineage leading to the present-day species of Gobius has important implications for the origin and evolution of the Gobiidae, and indicates that diversification of the European Gobiidae began in, but not before, the Early Miocene.http://zoobank.org/urn:lsid:zoobank.org:pub:3229739B-3428-4DFB-9588-4CE875D732D8

A new species of the fangblenny Adelotremus from Indonesia, with supplemental description of A. leptus (Teleostei: Blenniidae: Nemophini).

A new fangblenny, Adelotremus deloachi, is described on the basis of three specimens, 29‒35 mm SL, from Bali and Lembeh Strait, Indonesia. All these specimens were collected in 10‒17 m depth on sandy slopes. The new species differs from Adelotremus leptus, its Red Sea and only congener, in having a pair of mid-dorsal supratemporal pores (vs. a single pore), dorsal-fin spines X (vs. IX) and precaudal and caudal vertebra 12 + 23 (vs. 13 + 19). The discovery of a second species requires slight modification of the diagnosis of the genus. Unlike the five other nemophine genera, Adelotremus differs most notably in having the third infraorbital bone and associated sensory pores absent, and the combination of ventral margin of gill opening opposite the dorsalmost 5th or 6th pectoral-fin ray, total dorsal-fin elements 28‒29 and interorbital pores 2. With a total of four specimens of Adelotremus, it is now apparent that several features of the cephalic pore arrangement of the genus are different from that found in Petroscirtes, its presumed sister genus. Recent color photographs indicate that both species of Adelotremus exhibit marked sexual dichromatism with males having a conspicuous ocellus anteriorly in the dorsal fin that is absent in females.

From body scale ontogeny to species ontogeny: Histological and morphological assessment of the Late Devonian acanthodian Triazeugacanthus affinis from Miguasha, Canada.

Growth series of Palaeozoic fishes are rare because of the fragility of larval and juvenile specimens owing to their weak mineralisation and the scarcity of articulated specimens. This rarity makes it difficult to describe early vertebrate growth patterns and processes in extinct taxa. Indeed, only a few growth series of complete Palaeozoic fishes are available; however, they allow the growth of isolated elements to be described and individual growth from these isolated elements to be inferred. In addition, isolated and in situ scales are generally abundant and well-preserved, and bring information on (1) their morphology and structure relevant to phylogenetic relationships and (2) individual growth patterns and processes relative to species ontogeny. The Late Devonian acanthodian Triazeugacanthus affinis from the Miguasha Fossil-Lagerstätte preserves one of the best known fossilised ontogenies of early vertebrates because of the exceptional preservation, the large size range, and the abundance of complete specimens. Here, we present morphological, histological, and chemical data on scales from juvenile and adult specimens (scales not being formed in larvae). Histologically, Triazeugacanthus scales are composed of a basal layer of acellular bone housing Sharpey’s fibers, a mid-layer of mesodentine, and a superficial layer of ganoine. Developmentally, scales grow first through concentric addition of mesodentine and bone around a central primordium and then through superposition of ganoine layers. Ontogenetically, scales form first in the region below the dorsal fin spine, then squamation spreads anteriorly and posteriorly, and on fin webs. Phylogenetically, Triazeugacanthus scales show similarities with acanthodians (e.g. “box-in-box” growth), chondrichthyans (e.g. squamation pattern), and actinopterygians (e.g. ganoine). Scale histology and growth are interpreted in the light of a new phylogenetic analysis of gnathostomes supporting acanthodians as stem chondrichthyans.

Two new species of short-snouted dogfish sharks of the genus Squalus Linnaeus, 1758, from southern Africa (Chondrichthyes: Squaliformes: Squalidae)

Species composition of the genus Squalus from the eastern Atlantic and western Indian oceans is still poorly known, with three to four species often recognized: S. acanthias, S. megalops, S. blainvillei, and S. mitsukurii. A fifth species, S. acutipinnis, was recently redescribed as valid in the region, although morphological variation was noted among its type specimens that indicated the presence of two different forms. The second form is described herein as Squalus margaretsmithae sp. nov. and distinguished from S. acutipinnis based on external morphological characters. Squalus mahia sp. nov. is also described from southern Africa based mostly on material collected from Madagascar. Squalus mahia sp. nov. stands out from other Squalus species by having a conspicuously slender body, elongate and thin dorsal fin spines, narrow caudal fin, and other external proportions. These two species are often misidentified with the Australian S. megalops because they share a short snout, white postventral caudal margins, lanceolate and unicuspid dermal denticles, and a low number of vertebrae. Comparative analyses are provided here between Squalus margaretsmithae sp. nov., Squalus mahia sp. nov., and morphologically similar species that also share these features, including S. brevirostris, S. crassispinus, S. acutipinnis, S. altipinnis, and S. hemipinnis. A taxonomic evaluation of the nominal species S. megalops and its occurrence in the region is also discussed.

A new species of Otothyropsis (Siluriformes: Loricariidae) from the upper Río Paraná basin, Paraguay, with a discussion of the limits between Otothyropsis and Hisonotus.

Otothyropsis dialeukos is described from Itá creek, tributary to the upper Río Paraná basin, Paraguay. The new species is distinguished from its congeners by having a unique caudal-fin coloration pattern composed of a brown to almost black background with roundish hyaline blotches in the middle of the outermost branched rays and a hyaline posterior border interrupted in middle rays; abdomen entirely covered by enlarged plates, without naked areas; longer pectoral- and dorsal-fin spines; absence of a raised crest of enlarged odontodes on the posterior portion of the parieto-supraoccipital, and other morphometric and meristic features. Morphological traits and geographic distributions of all species of Otothyropsis and Hisonotus are analyzed and a discussion on the limits between those genera is presented.

†Tugenchromis pickfordi, gen. et sp. nov., from the upper Miocene—a stem-group cichlid of the ‘East African Radiation’

ABSTRACT The highly diverse tropical freshwater fish family Cichlidae is sparsely represented in the fossil record. Here we describe the new cichlid †Tugenchromis pickfordi, gen. et sp. nov., from the Upper Miocene (9–10 Ma) of central Kenya. The new taxon possesses a unique combination of characters, including six lateral line foramina on the lacrimal, three lateral line segments, cycloid scales, and a low number of vertebrae (29), dorsal fin spines (13), and dorsal soft rays (9). Its lacrimal morphology and tripartite lateral line suggest an affinity with the present-day Lake Tanganyika tribes Ectodini and Limnochromini, and thus with members of the ‘East African Radiation’ among the African cichlids. To further elucidate the relationships of †T. pickfordi, we used a comprehensive comparative data set comprising meristic data from all present-day tribes of the ‘East African Radiation.’ Principal coordinates analyses support links between the fossil and Ectodini + Limnochromini, and additionally with modern Haplochromini. We conclude that †T. pickfordi could be an extinct lineage within the ‘most ancient Tanganyika tribes,’ or a stem lineage of the ‘ancient Tanganyika mouthbrooders.’ A direct relationship to the Haplochromini is unlikely because its members do not exhibit the derived characteristics of the lacrimal as seen in †T. pickfordi. Because Lake Tanganyika is located in the western branch of the East African Rift System, †T. pickfordi from the eastern branch supports the ‘melting-pot Tanganyika hypothesis,’ which posits that the cichlids of modern Lake Tanganyika are derived from riverine lineages that had already diversified prior to the lake formation. http://zoobank.org/urn:lsid:zoobank.org:pub:37520070-99B3-463C-B8E6-9452D1F62722 SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP. Citation for this article: Altner, M., U. K. Schliewen, S. B. R. Penk, and B. Reichenbacher. 2017 . †Tugenchromis pickfordi, gen. et sp. nov., from the upper Miocene—a stem-group cichlid of the ‘East African Radiation’. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1297819.