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Volume 23, Issue 4 – 15 March 2018

Volume 23, Issue 4 – 15 March 2018
New Scientific publication – started delivery on July 25, 2018

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Dalton Tavares Bressane Nielsen, Mayler Martins, Luciano Medeiros de Araujo, Fabio Origuela de Lira and Amer Faour: Cynolebias akroa, a new species of annual fish (Cyprinodontiformes: Rivulidae) from the rio Preto, São Francisco basin, northeastern Brazil, pp. 113-121

Abstract

A new species of Cynolebias is described from temporary pools from the Rio Preto drainage, São Francisco basin, Bahia, Brazil, within the Caatinga domain. The type-locality is an altered aquatic environment, with the presence of exotic fish species and in contact with a permanent watercourse. Cynolebias akroa sp. n., along with Hypsolebias faouri, that inhabits the same annual pool, are in great danger of extinction. Cynolebias akroa sp. n., appears to be more closely related to Cynolebias parnaibensis, with which it shares several features, than to the remaining species of Cynolebias from the middle Rio São Francisco basin. Cynolebias akroa sp. n. differs from other species of Cynolebias by the male color pattern, relative position of dorsal fin to the anal fin, pelvic-fin rays counts, shape of the urogenital papilla, and cephalic neuro­mast pattern.

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Cynolebias akroa, ZUEC 14768, male, holotype, 75.0 mm SL: Brazil, Bahia, Santa Rita de Cássia. Photo by D. Nielsen

 

Mandy T. Etpison and Patrick L. Colin: Blue Water Spawning by Moorish Idols and Orangespine Surgeonfish in Palau: Is it a “Suicide Mission”?, pp. 121-136

Abstract

Spawning aggregations of the moorish idol (MI) and orangespine surgeonfish (OSS) were found on the western barrier reef of Palau. MI aggregated around the first quarter moon from Dec. to Mar., with largest groups in Jan. and Feb. Fish arrived near the sites in the morning, grouped together and moved up and down the reef face up in late morning attracting the attention of predators. At mid-day they ascend from the reef out into open water away from the reef. Gray reef sharks follow them and attack at the surface in a feeding frenzy. A high percentage of the ascending adults are eaten and few return safely to the reef. OSS aggregated in the same months, but on the last quarter moon with fewer observations being made. The observation of both fishes ascending high above and moving away from the reef to spawn is unusual and is termed “blue water spawning” with only a few similar examples known. Previously the importance of reef sharks in influencing reef fish spawning behavior has been reported as non-existent to “moderate” (a few spawning fish taken by sharks). This example of many individuals being taken by predators represents an extreme only reported previously for a grouper aggregation. The occurrence of sharks at the site during aggregation and spawning is indicative of a close relationship with reef fishes. The apparent high rate of predation on spawning MI and OSS may be specific to these study sites and it is likely individual fishes are generally iteropareous.

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Ascending aggregation of MIs (approximately 544 fish visible in photo) being shadowed by gray reef sharks, as they move towards the surface, Jan 2015. Photo copyright M. T. Etpison..

 

Flávio C. T. Lima and Gilberto N. Salvador: Fooled by a fish: seed camouflage by an Amazonian banjo catfish, Bunocephalus verrucosus (Siluriformes: Aspredinidae), pp. 137-145

Abstract

Seed camouflage (masquerade) by Bunocephalus verrucosus, an aspredinid catfish, is herein reported based on two observations of specimens that folded their caudal peduncle against the side of the body after being captured, in the region of Tefé, Central Amazon, Brazil. This is the second report of seed camouflage for aspredinid catfishes, the first being reported for Amaralia hypsiura. Types of camouflage among aspredinid catfishes are herein reported to range from masquerade, background matching, and disruptive coloration. Many seeds (mostly drupes) of the flooded forest may serve as potential models for Bunocephalus verrucosus across its range, particularly seeds of Chrysobalanaceae.

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Bunocephalus verrucosus, ZUEC 15094, 72.1 mm SL, preserved specimen, in dorsal, lateral, and ventral views. Photo by E. G. Baena.

 

Heiko Bleher: News of some Sicydiinae species from Babelthuap Island on the Palau archipelago, pp. 146-148

23_4_NEWS of some Sicydiinae

 

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