Back issuesUncategorized

Volume 11, Issue 3, September 2006

Volume 11, Issue 3 – September 2006

11-3

Full Text | PDF (1,2 MB)

Wouter Holleman: Fishes of the Helcogramma steinitzi species group (Blennioidei: Tripterygiidae) from the Indian Ocean, with descriptions of two new species, pp. 89-104

Abstract

Three species of Helcogramma from the Indian Ocean that form a monophyletic group are recognised: Helcogramma steinitzi Clark (Red Sea and Gulf of Oman), H. rosea n. sp. (Andaman Sea and Sri Lanka) and H. microstigma n. sp. (East African coast and adjacent islands). Helcogramma microstigma is distinguished from the other two species by a head profile of 67°-72° (about 60° in the other two species) and a long orbital cirrus (short and triangular in the other two species) and clusters of micromelanophores on the dorsum at the ends of the second and third dorsal fins of mature males (absent in the other two species). Helcogramma steinitzi has melanophores only on the distal half of the anal fin (in the other two species melanophores cover the entire fin) and a narrow interorbital (16.6 in head length). Helcogramma rosea has a sharper head profile of 56°-62°, similar to that of H. steinitzi, but is distinguished from it by anal fin pigmentation, a wider interorbital (about 15 in head length) and smaller size (maximum SL 33 mm cf. 47 mm for H. steinitzi). The three species in the group share a number of putative synapomorphies including very close-set first two dorsal-fin spines and densely packed micromelanophores on the membrane between these first two spines of both males and females. The close similarity of the species, their distribution, and comparisons to other tripterygiid species groups are discussed.

 

Abstract | Full Text | PDF (416 KB)

Helcogramma-500

 

 

Helcogramma steinitzi, BPBM 35926, male, 33 mm SL, southern Oman, near Marbat. Photo by J. E. Randall


 

John E. Randall: Three new species of the gobiid fish genus Tryssogobius from the western and South Pacific, pp. 105-116

Abstract

The small fishes of the gobiid genus Tryssogobius Larson & Hoese, 2001 are represented by the following five species: T. colini Larson & Hoese, 2001 from Indonesia, Malaysia, and Papua New Guinea in 27-41 m; T. flavolineatus n. sp. from New Guinea and Indonesia in 28-82 m; T. longipes Larson & Hoese, 2001 from Indonesia and Papua New Guinea in 19.5-27 m; T. nigrolineatus n. sp. from Fiji from 73-110 m; and T. quinquespinus n. sp. from Papua New Guinea in 27 m. They are distinguished primarily by fin-ray counts and in colour.

 

Abstract | Full Text | PDF (256 KB)

Tryssogobius-500

 

 

 

Tryssogobius flavolineatus, South Yapen Island, Papua Province, Indonesia. Photo by G. R. Allen

 

 


Ivan Sazima: Theatrical frogs and crafty snakes: predation of visually-signalling frogs by tail-luring and ambushing pitvipers, pp. 117-124

Resumo

Uma espécie de rã-da-cachoeira (Hylodes asper) é presa comum de duas espécies de jararacas (Bothrops jararacussu e B. jararaca) em riachos costeiros da Mata Atlântica do Sudeste do Brasil. As rãs são diurnas e sua coloração lhes confere camuflagem no substrato rochoso. Os machos advertem sua presença com uso de sinais visuais, movendo as pernas. Seus dedos e franjas digitais esbranquiçadas ficam conspícuos contra o substrato rochoso. Ademais, as rãs têm visão acurada, sendo capazes de localizar uma presa à distância de 2,8 m. Embora as jararacas sejam habitualmente noturnas, os juvenis de ambas as espécies capturam as rãs durante o dia. As rãs são tocaiadas ou atraídas por movimentos ondulatórios da cauda, que as jararacas usam para engodar presas ectotérmicas. Jararacas juvenis geralmente apresentam a ponta da cauda esbranquiçada ou amarelada, que sobressai das cores de camuflagem das serpentes enrodilhadas. Sugiro que a tática de engodar com a cauda, das jararacas, seja beneficiada pelo sistema de sinalização visual das rãs, uma vez que estas têm tendência a reagir a movimentos de extremidades de cores claras. Relação similar, entre presa e predador, poderia ocorrer em riachos tropicais que abriguem rãs que advertem visualmente e serpentes que se alimentam de anuros e engodam suas presas com a ponta colorida da cauda. 

Abstract | Full Text | PDF (384 KB)

Hylodes-500

 

 

 

 

A Hylodes asper male on a rock showing its conspicuous white digits. Photos by I. Sazima

 



Gerald R. Allen and Mark V. Erdmann: Cirrhilabrus cenderawasih, a new wrasse (Pisces: Labridae) from Papua, Indonesia, pp. 125-131

Abstract

Cirrhilabrus cenderawasih is described from seven specimens, 38.9-65.1 mm SL, collected at Cenderawasih Bay, Papua, Indonesia. It is closely related to C. walindi from Papua New Guinea and the Solomon Islands, but differs with regards to male colour pattern, particularly the number, shape and position of large dark blotches along the back and adjacent dorsal fin. There are 4-5, irregularly rounded blotches that extend well onto the back in C. cenderawasih in contrast to only two, rectangular blotches for C. walindi that are primarily positioned on the dorsal fin. It is hypothesized that these species arose from a common ancestor that was once widely distributed along the northern margin of the New Guinea-Australian Plate, but land and current barriers formed over the past few million years have facilitated isolation and eventual speciation in the Cenderawasih Bay population.

Abstract | Full Text | PDF (160 KB)

Cirrhilabrus-500

 

 

 

 

Underwater photograph of male Cirrhilabrus cenderawasih, approximately 70 mmTL, 25 m depth, Cenderawasih Bay, Papua. Photo by G. R. Allen


Previous post

Cirrhilabrus cenderawasih, a new wrasse (Pisces: Labridae) from Papua, Indonesia

Next post

Volume 11, Issue 4, October 2006

The Author

Rossella

Rossella

No Comment

Leave a reply