Wednesday, February 22, 2017

[Ichthyology • 2016] Pempheris gasparinii • A New Species of Sweeper Fish (Teleostei, Pempheridae) from Trindade Island, southwestern Atlantic


Pempheris gasparinii 
 Pinheiro, Bernardi & Rocha, 2016

Abstract
Pempheris gasparinii sp. n. is described from five specimens, 59.1–68.0 mm in standard length. It is only known to occur in the shallow reefs of Trindade Island, 1200 km east of the Brazilian coast, in the southwestern Atlantic. Pempheris gasparinii is the third recognized species of Pempheris in the Atlantic Ocean. This new species is morphologically similar to its close relative, P. poeyi, differing by the number of lateral-line scales (51–54 in P. gasparinii vs. 47–49 in P. poeyi), scales below lateral line (10–11 vs. 9), circumpeduncular scales (11–12 vs. 13), head and caudal peduncle lengths (2.7–3.3 vs 3.5–4.0 in head length). Moreover, Pempheris gasparinii shows a 4% genetic divergence from P. poeyi at the cytochrome oxidase I locus (COI), consistent with a lineage split at the beginning of the Pleistocene. This new species represents the 12th endemic fish species from Trindade Island.

Keywords: Endemism, COI, Vitória-Trindade Chain, oceanic island, Brazil, reef fish


   

Figure 1. Underwater picture of Pempheris gasparinii sp. n. at the Parcel Pool, Trindade Island (top; photo J.L. Gasparini), and a specimen shortly after death (bottom; photo T. Simon). 

Diagnosis: Pempheris gasparinii differs from its congeners by the following combination of character states: Head 3.2–3.7 in SL; body depth 2.7 in SL; head length 3.2–3.7 in SL; orbit diameter 1.9–2.7 in HL; caudal-peduncle depth 2.7–3.3 in HL; dorsal rays IV, 8–9; anal-fin rays III, 24–25; pectoral rays 15; lateral-line scales 51–54; scales below the lateral line 10–11; circumpeduncular scales 11–12; and gill rakers 23–25. Color in life mostly silvery, darker from mid-body to the lateral line and greenish above; fins are translucent with a darker tail. Color in alcohol light brown to silvery with darker dorsum and translucent fins; caudal fin darker. Additionally, mitochondrial DNA COI sequences show a divergence of at least 4% from all Atlantic congeners.

Etymology: The specific name honors our ichthyologist colleague and friend João Luiz Rosetti Gasparini, one of the pioneers on the study of taxonomy and biodiversity of reef fishes in Brazil and Trindade Island. “Gaspa” has contributed to nearly half of the descriptions of reef-fish species from Brazilian waters in the last two decades. To be treated as a noun in apposition.

Distribution and habitat: Pempheris gasparinii sp. n. is known only from the type locality, Trindade Island, Espírito Santo, Brazil. It has only been found schooling in the very shallow waters of the rocky Parcel pools (Figure 3).

Figure 3. Parcel Pool, Trindade Island, Brazil, type locality of Pempheris gasparinii sp. n. (photo H.T. Pinheiro). 

 Hudson T. Pinheiro, Giacomo Bernardi and Luiz A. Rocha. 2016. Pempheris gasparinii, A New Species of Sweeper Fish from Trindade Island, southwestern Atlantic (Teleostei, Pempheridae). ZooKeys. 561; 105-115. DOI:  10.3897/zookeys.561.7263


No comments:

Post a Comment