Samstag, 19 Dezember 2020 14:37

BECKMANN-DAHL, R. (2019)

The Sandy Zebra Shark: A New Color Morph of the Zebra Shark Stegostoma tigrinum, with a Redescription of the Species and a Revision of Its Nomenclature.

Copeia, 107(3):524-541 (2019). https://doi.org/10.1643/CG-18-115

Abstract:

The Zebra Shark, in recent years known as Stegostoma fasciatum (Hermann, 1783), is well known for its dramatic ontogenetic change of color pattern, from striped (“zebra”) juveniles to spotted (“leopard”) adults. Nevertheless, many aspects of the species' biology, ecology, and morphology are still unknown or inadequately described, and its nomenclature is contentious. This study introduces a hitherto undescribed color morph of the Zebra Shark and provides an updated diagnosis and redescription of the species. Firstly, we establish that the Zebra Shark remains a single species based on genetic data from mitochondrial COI and ND4 markers. Secondly, through morphological analyses, we conclude that there are two morphs of the species, the known, zebra striped morph and a new, sandy colored morph. Both morphs were studied morphometrically to expose any ontogenetic changes, such as a decrease in the relative length of the tail with increasing total length (TL). The external coloration pattern clearly differentiates the two morphs, and both morphs can be further divided into three stages based on color pattern and size: juveniles (255–562 mm TL), transitionals (562–1395 mm TL), and adults (>1300 mm TL). The transitional sandy morph is dorsally covered by a swirly pattern of thin, dark brown bands edged with freckle-like brown spots. The adults are a uniform sandy beige, partially covered with brown freckles. A mature male of the zebra morph displayed a yet unknown feature of the claspers: a small, triangular spike extruding from the dorsal terminal of the clasper glands. Finally, we reviewed the nomenclature of the species and suggest that the original name Stegostoma tigrinum Forster, 1781, should be used as the senior synonym for the species.

beckmann-biblio

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Mittwoch, 02 September 2020 15:33

MILLER, C. (2020)

Der Aal - ein geheimnisvoller Wanderer.

FAUNA FOCUS Nr. 61. 12 Seiten.
Hrsg.: WILDTIER SCHWEIZ

Verlagstext:

Der europäische Aal ist ein Fisch der Rekorde: Er ist die am weitesten verbreitete Fischart Europas, gleichzeitig zählt er heute zu den am meisten gefährdeten Fischen. Er legt die weitesten Wanderungen zu seinen Laichgewässern zurück. Und schliesslich zählt er zu den geheimnisvollsten Fischarten.
Der aussergewöhnliche Lebenswandel der Aale macht es überaus schwierig sie zu erforschen: Wanderfische, die ihren Laich im Salzwasser ablegen und ihre Fress- und Wachstumsphase im Süsswasser verbringen, gibt es nur wenige. Die meisten wandernden Fische, wie Lachse und Meerforellen, leben im Salzwasser und laichen im Süsswasser.

Weltweit gibt es rund 20 Aalarten, von welchen die meisten weite Wanderungen zurücklegen. Bis heute ist es jedoch nicht gelungen die genauen Wanderrouten auch nur einer Aalart genau nachzuvollziehen. Sobald sie die Küstengewässer hinter sich lassen und in tiefere Meeresschichten abtauchen verliert sich ihre Spur.

miller-biblio

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Montag, 03 August 2020 10:29

CARPENTER, K.E. (ed., 2002)

The living marine resources of the Western Central Atlantic.

Volume 2: Bony fishes part 1 (Acipenseridae to Grammatidae).

FAO Species Identification Guide for Fishery Purposes and American Society of Ichthyologists and Herpetologists Special Publication No. 5.Rome, FAO. 2002. pp. 601-1374.

Summary:

This 3 volume field guide covers the species of interest to fisheries of the major marine resource groups exploited in the Western Central Atlantic. The area of coverage includes FAO Fishing Area 31. The marine resource groups included are the bivalves, gastropods, cephalopods, stomatopods, shrimps, lobsters, crabs, hagfishes, sharks, batoid fishes, chimaeras, bony  fishes, sea  turtles,  nd marine mammals. The introductory chapter outlines the environmental, ecological, and  biogeographical factors influencing the marine biota, and the basic components of the fisheries in the Western Central Atlantic. Within the field guide, the sections on the resource groups are arranged phylogenetically according to higher taxonomic levels such as class, order, and family. Each resource group is introduced by general remarks on the group, an illustrated section on technical terms and measurements, and a key or guide to orders or families. Each family generally has an account  summarizing family diagnostic characters, biological and fisheries information, notes on similar families occurring in the area, a key to species, a checklist of species and a short list of relevant literature. Families that are less important to fisheries include an abbreviated family account and no detailed species information. Species in the important families are treated in detail (arranged alphabetically by genus and species) and include the species name, frequent synonyms and names of similar species, an illustration, FAO common name(s), diagnostic characters, biology and fisheries information, notes on geographical distribution, and a distribution map. For less important spe-cies, abbreviated accounts are used. Generally, this includes the species name, FAOc ommon name(s), an illustration, a distribution map, and notes on biology, fisheries, anddistribution. The final volume concludes with an index of scientific and common names.

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Sonntag, 19 Juli 2020 07:26

DE SANTANA, C. D. et al. (2019)

Unexpected species diversity in electric eels with a description of the strongest living bioelectricity generator.

Nature Communications volume 10, Article number: 4000 (2019). https://www.nature.com/articles/s41467-019-11690-z

Abstract:

Is there only one electric eel species? For two and a half centuries since its description by Linnaeus, Electrophorus electricus has captivated humankind by its capacity to generate strong electric discharges. Despite the importance of Electrophorus in multiple fields of science, the possibility of additional species-level diversity in the genus, which could also reveal a hidden variety of substances and bioelectrogenic functions, has hitherto not been explored. Here, based on overwhelming patterns of genetic, morphological, and ecological data, we reject the hypothesis of a single species broadly distributed throughout Greater Amazonia. Our analyses readily identify three major lineages that diverged during the Miocene and Pliocene—two of which warrant recognition as new species. For one of the new species, we recorded a discharge of 860 V, well above 650 V previously cited for Electrophorus, making it the strongest living bioelectricity generator.

santana-biblio; de santana-biblio

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Donnerstag, 05 April 2018 14:55

YOSHINO, T. & SHIMADA, K. (2001)

Stonogobiops yasha, a new shrimp-associated goby from Japan.

Ichthyol. Res. (2001) 48: 405–408.

Abstract:

A new shrimp-associated goby, Stonogobiops yasha sp. nov., is described on the basis  of  nine  specimens  collected  from  the  Ryukyu  Islands,  Japan.  This  species  is  easily distinguished  from  other  congeneric  species  in  having  reddish-orange  stripes  on  a  white body and only two median cephalic sensory pores on the head.

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Mittwoch, 04 April 2018 10:00

HOESE, D. F. & LARSON, H. K. (1994)

Revision of the Indo-Pacific Gobiid Fish Genus Valenciennea, with Descriptions of Seven New Species.

71 Seiten, 6 Bildtafeln mit 35 Farbfotos, 11 Strichzeichnungen und Verbreitungskarten, 26 Tabellen.
Bishop Museum, Hawaii.

Inhalt:

The Indo-Pacific gobiid genus Valenciennea is distinctive from other gobiids in having completely separate pelvic fins, reduced gill rakers on the first arch, large fleshy flaps dorsally on the gill arch, single row of teeth in the upperjaw, small scales in 62-142 rows, second dorsal and anal rays I,11-19, relatively large adult body size of 30 to about 160 mm SL, and usually with one or more longitudinal stripes on the head and often the body.

Fifteen species are recognized, separable on the basis of scale and fin-ray counts, first dorsal fin shape, and color pattern: V. alleni, n. sp., described from Australia, has 2 stripes on the body, a black spot at the tip of the first dorsal fin, and second dorsal rays usually I,15; V. bella, n. sp. from Japan and the Philippines, has a single head stripe, no body stripes, second dorsal usually I,15, and a high first dorsal fin; V. decora, n. sp. from Australia and New Caledonia, has one or more vertical bars connected to a single ventral stripe, an elongate black bar on the first dorsal fin, and second dorsal I,11; V. helsdingenii, widespread in the Indo-west Pacific, has an elongate black spot on the first dorsal fin, 2 dark stripes on the body, and 2 elongate filaments on the caudal fin; V. immaculata, with a disjunct distribution (China, Western Australia, and southeastern Australia), has 2 stripes on the body, a low rounded first dorsal fin without black spots, and second dorsal usually I,14-17 (it is most similar to V. alleni); V. limicola, n. sp. described from Thailand and Fiji, has 2 stripes on the body, a low rounded first dorsal fin without black spots, and second dorsal usually I,17; V. longipinnis, a widespread species from the eastern Indian Ocean and western Pacific, has a low rounded first dorsal fin, horseshoe-shaped marks on the midside, and second dorsal I,12; V. muralis, similar to and having the same distribution as V. longipinnis, has 3 stripes on the body, a pointed first dorsal fin. with a small black spot at the tip, and second dorsal I,12; V. parva, n. sp., a widespread Indo-west Pacific dwarf species, has longitudinal stripes, a low rounded first dorsal fin, and second dorsal I,12 (juveniles are easily mistaken for V. longipinnis, which has higher scale counts); V. persica, n. sp., endemic to the Persian Gulf, has a single stripe posteriorly on the body, a longitudinal series of spots above the midside, and second dorsal ray counts of I,13-14 (it is most similar to V. puellaris); V. puellaris, a widespread Indo-west Pacific species which varies considerably geographically is distinctive in having a moderately high first dorsal fin without black spots, body with a single stripe and spots or oblique or vertical bars on body, and second dorsal I,12; V. randalli, n. sp. from the western Pacific, has a high first dorsal fin, a single stripe on the body, and second dorsal usually I,l7 (it is similar to V. bella and V. strigata); V. sexguttata, a widespread Indo-west Pacific species, has a pointed first dorsal fin with a black spot at the tip, round spots on the head, a single stripe on the body, and second dorsal I,l2; V. strigata, a widespread Indo-west Pacific species, has a high first dorsal fin without black spots, no stripe on the body, and second dorsal usually I,17-18; V. wardii, a rare, but widespread Indian Ocean and western Pacific species, has a large black spot posteriorly on the first dorsal. a series of vertical bars, no stripe on body, and second dorsal I,12.

Fishes of the genus dig their own burrows and most species occur in male-female pairs. These fishes feed on small invertebrates, particularly copepods, by sifting sand. The species are typically associated with specific types of sediment, and only rarely does more than one species occur in the same habitat.

Considerable geographical variation was found in fin-ray and scale counts in several species, but only V. puellaris, V. sexguttata, and V. wardii showed much variation in coloration.

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Dienstag, 20 März 2018 11:27

PAEPKE, H.-J. & SCHINDLER, I. (2002)

Zur Erstbeschreibung von Pterophyllum scalare (Schultze in Lichtenstein, 1823) (Pisces, Cichlidae).

Mitt. Mus. Natkd. Berl., Zool. Reihe 78 (2002) 1: 177-182.

Abstract:

The present study reports new data concerning the terra typica (lower amazon river eastward of Óbidos including the lower part of Rio Tocantins near Cametá), the collector (Friedrich Wilhelm Sieber), and the authorship of the cichlid species Pterophyllum scalare first described as Zeus scalaris (Schultze in Lichtenstein, 1823). The only type specimen still in existence (ZMB 2833) is described and designated as lectotype.

Volltext (deutsch)

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Dienstag, 13 März 2018 10:48

SCHLIEWEN, U. (2009)

Italienische Süßwassergrundeln der Gattung Padogobius

AKFS-aktuell 24/2009: 1-5.

Artikelanfang:

Eigentlich ist die Sache der aktuellen Literatur nach  klar:  In  Italien  gibt  es  genau  zwei Süßwassergrundeln aus der Gattung Padogobius, P. bonelli (Bonaparte, 1846) und  P. nigricans (Canestrini, 1867) (Miller 2004a). Die meisten irgendwie  an Grundeln interessierten Aquarianer kennen die Art, die im norditalienischen Gardasee vorkommt („Gardasee-Grundel“), wo sie sich ihren Lebensraum unter anderem mit dem Süßwasserschleimfisch Salaria fluviatilis teilt. Diese Art ist P. bonelli, wurde früher aber auch als Gobius  fluviatilis Nardo, 1824, Gobius martensii Günther, 1861 oder ganz falsch als Padogobius panizzai (nicht zu verwechseln mit Knipowitschia panizzae) angesprochen. Gobius martensii ist nach derzeitigem Kenntnisstand aber ein Synonym zu P. bonelli (Kottelat 1997). Die Lagunengrundel Knipowitschia panizzae dagegen ist eine ganz andere Art aus einer völlig anderen  Verwandtschaftsgruppe  und hat mit der „Gardaseegrundel“ gar  nichts zu tun. Padogobius bonelli kommt in der Schweiz und in Italien im Einzug des Po (inklusive Lago di Garda und Lago Maggiore) vor, sowie in vielen  nordadriatischen  kleineren  Flusssystemen von Italien über Slowenien bis nach Kroatien (südlichste  kroatische Population in den Flüssen Zrmanje und  Krka) (Elmiger 2002, Miller 2004b). Die zweite Padogobius-Art, P. nigricans ist ein Endemit Italiens und besiedelt Zuflüsse des Thyrrenischen Meeres (Arno, Ombrone, Tiber und Amaseno-Einzug) (Miller 2004c). Allerdings wurde und wird P. bonelli wohl immer noch mehr oder weniger in ganz Italien durch Besatzmaßnahmen transplantiert und hat sich im Laufe der Zeit zu einer Bedrohung für P. nigricans entwickelt. Zumindest in einigen Flussystemen scheint P. bonelli wesentlich konkurrenzstärker als P. nigricans zu sein, so dass letztere Art oft nur noch in den Oberläufen der besetzten Flusssysteme unbeeinflusst zu finden ist (Miller 2004c). 

Volltext:

http://docplayer.org/71372719-Italienische-suesswassergrundeln-der-gattung-padogobius.html

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Freitag, 02 März 2018 11:43

LOISELLE, P. V. & RODRIGUEZ, D. (2007).

A new species of Bedotia (Teleostei: Atherinomorpha: Bedotiidae) from the Rianila drainage of eastern Madagascar, with redescriptions of Bedotia madagascariensis and Bedotia geayi.

Zootaxa 1520: 1–18. ISSN 1175-5334.

Abstract:

Bedotia  madagascariensis Regan 1903, type species of the genus and B. geayi Pellegrin 1907 are  redescribed from recently collected topotypical material. The two species differ significantly with respect to their life colors, the lengths ofthe head, snout, caudal peduncle and bases of the second dorsal and anal fins as well as their second dorsal and anal finray counts.

The aboriginal range of B. madagascariensis comprises eastward flowing streams from the Ivoloina River southward to Manambolo Creek inclusive of small streams flowing into the coastal lakes of the Pangalanes system situated between them, where it occurs up to an altitude of 30 m above sea level. A naturalized population is present in the westward-flowing Betsiboka drainage. Bedotia geayi is only known from the eastward-flowing Mananjary River, where it can be found in small streams between 300 m and 600 m above sea level. A second species of Bedotia from the Rianilabasin is described.

Bedotia leucopteron sp. nov. is found in shaded streams between 100 m and 850 m above sea level.The wide, iridescent white margins of the unpaired fins taken in combination with a melanophore pattern consisting ofsmall, irregular black spots stochastically distributed over the flanks rather than a distinct midlateral band differentiateliving individuals from all known congeners. Data on the natural history and conservation status of all three species are presented.

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Discovery of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Santa Fe River drainage, Suwannee River basin, USA.

BioInvasions Records (2012) Volume 1, Issue 3: 179–200
doi:  http://dx.doi.org/10.3391/bir.2012.1.3.04

Abstract:

We report on the occurrence of South American suckermouth armored catfishes (Loricariidae) in the Suwannee River basin, southeastern USA. Over the past few years (2009-2012), loricariid catfishes have been observed at various sites in the Santa Fe River drainage, a major tributary of the Suwannee in the state of Florida. Similar to other introduced populations of Pterygoplichthys, there is high likelihood of hybridization. To date, we have captured nine specimens (270-585 mm, standard length) in the Santa Fe River drainage. One specimen taken from Poe Spring best agrees with Pterygoplichthys gibbiceps (Kner, 1854) or may be a hybrid with either P. pardalis or P. disjunctivus. The other specimens were taken from several sites in the drainage and include seven that best agree with Pterygoplichthys disjunctivus (Weber, 1991); and one a possible P. disjunctivus × P. pardalis hybrid. We observed additional individuals, either these or similar appearing loricariids, in Hornsby and Poe springs and at various sites upstream and downstream of the long (> 4 km) subterranean portion of the Santa Fe River. These specimens represent the first confirmed records of Pterygoplichthys in the Suwannee River basin. The P. gibbiceps specimen represents the first documented record of an adult or near adult of this species in open waters of North America. Pterygoplichthys disjunctivus or its hybrids (perhaps hybrid swarms) are already abundant and widespread in other parts of peninsular Florida, but the Santa Fe River represents a northern extension of the catfish in the state. Pterygoplichthys are still relatively uncommon in the Santa Fe drainage and successful reproduction not yet documented. However, in May 2012 we captured five adult catfish (two mature or maturing males and three gravid females) from a single riverine swallet pool. One male was stationed at a nest burrow (no eggs present). To survive the occasional harsh Florida winters, these South American catfish apparently use artesian springs as thermal refugia. In the Santa Fe River, eradication might be possible during cold periods when catfish congregate in spring habitats. However, should Pterygoplichthys increase in number and disperse more widely, the opportunity to eliminate them from the drainage will pass.

Discovery of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Santa Fe River drainage, Suwannee River basin, USA (PDF Download Available). Available from: https://www.researchgate.net/publication/264375985_Discovery_of_South_American_suckermouth_armored_catfishes_Loricariidae_Pterygoplichthys_spp_in_the_Santa_Fe_River_drainage_Suwannee_River_basin_USA [accessed Feb 28 2018].

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© Peter Dollinger, Zoo Office Bern hyperworx