Chirocentrids as engrauloids: evidence from suspensorium, branchial arches, and infraorbital bones (Clupeomorpha, Teleostei)

Abstract

The Chirocentridae is a family of highly specialized large predatory clupeomorphs composed of two species from coastal waters of the Indian and western Pacific Oceans. Peculiarities of the anatomy of these fishes have puzzled ichthyologists who attempted to resolve their phylogenetic relationships. Despite controversy, it is currently accepted that the Chirocentridae is a family of Clupeiformes, included with the Clupeidae in the superfamily Clupeoidea. New data support an alternative hypothesis. Seven previously unreported derived character states from the suspensorium, branchial arches, and infraorbitals strongly indicate a hitherto unsuspected sister group relationship between the Chirocentridae and Engrauloidea, which comprises approximately 140 species of the commercially important fishes known as anchovies. These are character states: (1) the anterior margin of metapterygoid located anterior to the quadrate; (2) the ventral limb of hyomandibula and quadrate not separated by the metapterygoid; (3) the posterodorsal margin of metapterygoid in line with the condyle of articulation of the hyomandibula with the opercle; (4) the presence of a laminar outgrowth of the anterior margin of the quadrate; (5) the endochondral portion of the quadrate in the shape of an isosceles triangle; (6) the presence and arrangement of autogenous tooth plates on ceratobranchials 1 to 3; and (7) posterior region of infraorbital 1 well developed and extending along the ventral margin of infraorbital 2. Three of those character states are further modified and hypothesized as synapomorphies of the Engrauloidea: (1′) a substantial portion of the metapterygoid situated anterodorsal to the quadrate, (2′) articulation between the ventral limb of the hyomandibula and the quadrate, and (7′) infraorbitals 1 and 3 articulating by means of a well-developed laminar process of the posterior region of infraorbital 1. The separation of the dorsal, paired elements of the branchial arches of the Chirocentridae and representative Engrauloidea is apomorphic within the Clupeoidei, and constitutes circumstantial evidence for the sister group relationship between those clades. Microphagy within the Engrauloidea is secondary, homoplastic to the same condition present in other clades of the Clupeiformes. The decomposition of character complexes into discrete morphological characters and its use in phylogenetic inference is discussed. The sister group relationship between the Chirocentridae and Engrauloidea renders the Clupeoidea paraphyletic. A new classification of the Clupeoidei, with the inclusion of the Chirocentridae in the Engrauloidea, is proposed.

Unique occipital articulation with the first vertebra found in pristigasterids, chirocentrids, and clupeids (Teleostei: Clupeiformes: Clupeoidei)

“…On the phylogenetic relationships of the other families in Clupeoidei, there are various hypotheses (Sato 1994;Fig. Di Dario 2002Dario , 2009Lavoué et al 2007Lavoué et al , 2008Li and Ortí 2007). Nevertheless, these hypotheses can be divided into two ideas.…”

“…The occurrence of the W-shaped occipital articulation is not inconsistent with the hypothesis of the close relationship of these two families. Most recently, Di Dario (2009) proposed that chirocentrids are separate from the superfamily Clupeoidea (sensu Grande 1985) and are contained within the Engrauloidea, based on the osteology of the suspensorium, branchial arches, and infraorbitals. However, the occurrence of the W-shaped occipital articulation is inconsistent with this hypothesis.…”

“…The W-shaped occipital articulation is not found in Denticeps as a sister group to the suborder Clupeoidei; therefore, this occipital articulation is obviously thought to be a derived character. Within Di Dario's (2002Dario's ( , 2009 phylogenetic context, this character is interpreted as a synapomorphy of the suborder Clupeoidei, and the condition that the first vertebral neural arch bases do not extend anteriorly in engraulids is regarded as a reversal. In contrast, the occurrence of the W-shaped occipital articulation is congruent with the topology based on the cladistic analysis proposed by Sato (1994) and recent molecular phylogenetic studies (Lavoué et al 2007(Lavoué et al , 2008Li and Ortí 2007).…”

Reassessment and Relationships of †Scutatuspinosus itapagipensis (Teleostei, Clupeomorpha, †Ellimmichthyiformes) from the Neocomian of Recôncavo Basin, Northeastern Brazil

“…Although ancient, †Scutatuspinosus shows many skeletal specializations, some are homoplastically found outside †Ellimmichthyiformes, such as non-triangular abdominal scutes (shared with †Santanaclupea, from the Lower Cretaceous of Araripe Basin, see Maisey 1993) and straight and elongate maxilla (see Di Dario 2009). According to our results, the basal position of the †Scutatuspi-nosus within †Paraclupeidae permits the inference of a minimum age for that group corresponding to the Hauterivian-Barremian interval.…”

A new species of Anchoviella Fowler, 1911 (Clupeiformes: Engraulidae) from the Amazon basin, Brazil

“…According to Whitehead et al (1988) the genus is distinguished in the Engraulidae by a body slightly compressed, the presence of numerous elongate gill rakers (usually more than 15 on the lower branch of the first gill arch) and a short upper jaw (not extending posteriorly to the vertical through the anterior margin of the opercle). Members of the Engraulidae, which includes approximately 140 species, are typically schooling coastal fishes commonly known as anchovies (English) or "manjubas" in the Brazilian Portuguese (Nelson, 2006;Di Dario, 2009). Jordan & Seale (1926) recognized 18 valid species of Anchoviella.…”