Wednesday, October 19, 2016

[Ichthyology • 2007] Lutjanus alexandrei • A New Species of Snapper (Perciformes: Lutjanidae) from Brazil, with Comments on the Distribution of Lutjanus griseus and L. apodus

Lutjanus alexandrei
 Moura & Lindeman, 2007 

Snappers of the family Lutjanidae contain several of the most important reef-fishery species in the tropical western Atlantic. Despite their importance, substantial gaps exist for both systematic and ecological information, especially for the southwestern Atlantic. Recent collecting efforts along the coast of Brazil have resulted in the discovery of many new reef-fish species, including commercially important parrotfishes (Scaridae) and grunts (Haemulidae). Based on field collecting, museum specimens, and literature records, we describe a new species of snapper, Lutjanus alexandrei, which is apparently endemic to the Brazilian coast. The newly settled and early juvenile life stages are also described. This species is common in many Brazilian reef and coastal estuarine systems where it has been often misidentified as the gray snapper, Lutjanus griseus, or the schoolmaster, L. apodus. Identification of the new species cast doubt on prior distributional assumptions about the southern ranges of L. griseus and L. apodus, and subsequent field and museum work confirmed that those species are not reliably recorded in Brazil. The taxonomic status of two Brazilian species previously referred to LutjanusBodianus aya and Genyoroge canina, is reviewed to determine the number of valid Lutjanus species occurring in Brazil. Twelve species of Lutjanus are now recognized in the western Atlantic, eight of which occur in Brazil (one endemic). A key for the identification of all western Atlantic Lutjanus species and their known distributional ranges is also provided.

Key words: Lutjanus alexandrei new species; snappers; biogeography; Brazil

FIGURE 2. Underwater photograph of Lutjanus alexandrei. Parcel das Paredes (17°53’54”S, 38°57’13”W), Abrolhos Bank, Bahia, Brazil (R.L. Moura).

 FIGURE 3. Early juvenile individual of Lutjanus alexandrei, 27 mm SL, collected in the mouth of Rio Mamucabas, Tamandaré (08°49'S, 035°05'W), State of Pernambuco, Brazil, 1 m depth (Beatrice P. Ferreira & Sérgio Resende, 18 February 2005).

Etymology. The specific name honors the pioneer Brazilian naturalist Alexandre Rodrigues Ferreira (1756–1815), whose many years of field work in Brazil during the late 18th Century remain underrecognized due to the confiscation of his and others’ collections at Lisbon’s Museu da Ajuda in 1808 (Oliveira & Daly 2001). Ferreira collected many specimens that were ultimately described as new without any reference to his efforts. The common name Brazilian snapper is proposed for L. alexandrei.

Distribution, ecology and behavior. The Brazilian snapper, Lutjanus alexandrei is only recorded from the tropical portion of the southwestern Atlantic continental shelf, and has a narrower latitudinal range than other Western Atlantic species of Lutjanus. It is known from the state of Maranhão (00°52’S) to the southern coast of the state of Bahia (18°0’S), Brazil, in areas under the influence of the west-flowing Equatorial Current (northern Brazil) and the south-flowing Brazil Current (northeastern Brazil). It is apparently absent from oceanic islands. Additional collections may show an even broader distributional range for this species, as was the case with 48 other poorly known reef-fish species in the southwestern Atlantic (Moura et al. 1999).

Habitats of the Brazilian snapper include coral reefs, rocky shores, coastal lagoons with brackish water, mangroves and other shallow habitats with a mixture of soft- and hard-bottom. Recorded depths range from intertidal (early stages only) to at least 54 m (Feitoza et al. 2005 — identified as L. apodus). During the day, adults of Lalexandrei were observed on reefs as solitary individuals or in small groups showing restricted activity. Adults can co-occur with L. jocu (see figure on page 40 in MMA 2002, several L. alexandrei were misidentified as L. jocu). These mixed groups are often composed of large (> 20 cm), probably adult, individuals. Similar to several other Lutjanus species, this species appears to be active predominantly during crepuscular and nocturnal periods. Juveniles smaller than 10 cm SL can be common in mangroves and rocky tidepools, sometimes together with L. jocu juveniles, and may also occur in other shallow habitats. Based on available information, early juvenile stages of L. alexandrei are uncommon or rare in deeper, offshore reef habitats, as in many congeners (Lindeman et al. 1998, Lindeman & DeMaria 2005).

Rodrigo L. Moura and Kenyon C. Lindeman. 2007. A New Species of Snapper (Perciformes: Lutjanidae) from Brazil, with Comments on the Distribution of Lutjanus griseus and L. apodus.  Zootaxa. 1422: 31–43.

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