Facial and gill musculature of polynemid fishes, with notes on their possible relationships with sciaenids (Percomorphacea: Perciformes)

Abstract

The Polynemidae is a family of primarily marine fishes with eight genera and 42 extant species. Many aspects of their morphology are largely unknown, with few reports about their osteology and barely any information on their myology. This paper describes and illustrates in detail all facial and branchial muscles of representative species of polynemids. Our analysis demonstrates the existence of several remarkable and previously unknown specializations in the polynemid musculature. The aponeurotic and completely independent origin of the pars promalaris of the adductor mandibulae is apparently unique among percomorphs. The differentiation of this section into lateral and medial subsections; the total separation of the promalaris from the retromalaris; the differentiation of the pars primordialis of the levator arcus palatini into external and internal subsections are also uncommon features of polynemids that are shared by sciaenids, thus supporting the hypothesis of a closer relationship between these families. K E Y W O R D S anatomy, morphology, myology, Polynemidae, threadfin

Anatomy and evolution of the pectoral filaments of threadfins (Polynemidae)

“…In most percomorphs, the abductor musculature arises solely from the cleithrum and coracoid, and, in only a few cases, small fibers also originate from the radials (e.g., Gadus 21 ). The abductor profundus radii of all examined polynemids has small fibers originating from pectoral radial 3, a condition not found in any of the examined representatives of taxa proposed as possibly closer to polynemids (Mugilidae, Sciaenidae, and Sphyraenidae) based on morphology 3,8,14,[45][46][47][48][49][50] . According to Winterbottom 21 the arrector dorsalis is the first muscle to separate from the whole medial muscle mass during ontogeny.…”

“…Examined specimens are from the following institutions: Academy of Natural Sciences of Drexel University, USA (ANSP); California Academy of Sciences, USA (CAS); Natural History Museum of Los Angeles County, USA (LACM); and Museu de Zoologia da Universidade de São Paulo, Brazil (MZUSP). In total, 25 adult specimens representing 19 polynemid species were double stained for analysis of their skeleton, musculature, and innervation: Eleutheronema tetradactylum (1) 14 . Additionally we examined an ontogenetic series of Polydactylus approximans (LACM 9789-2), ranging from 4 to 21.3 mm standard length (SL).…”

“…Sphyraenidae: Sphyraena tome (1) MZUSP 47,562. Mugilidae: Mugil curema (1) MZUSP 67314 14 . Access to material of these collections and permission for dissections were duly authorized by the respective curators.…”

“…A few generalized aspects of the innervation in a polynemid was provided by Freihofer 13 . Only more recently, Presti et al 14 provided detailed descriptions and illustrations of the facial and gill-arch musculature of several polynemids.…”

Skeletal remains with otoliths in situ of the Miocene croaker Trewasciaena cf. kokeni (Teleostei, Sciaenidae) from the Pannonian of the Vienna Basin

“…Considered to be closely related to the Haemulidae (Trewavas 1977, Schwarzhans 1993, the family Sciaenidae is currently aligned with the Polynemidae based on the shared possession of a suite of muscular and skeletal features (Johnson 1993, Presti et al 2020. Sciaenids can be easily defined based on a number of features that can be regarded as diagnostic of the family (Trewavas 1977, Chao 1978, including large and complex swimbladder and associated well-developed drumming muscles, enlarged lateral-line canals on the head and pores on the snout and lower jaws and extension of the lateral line to the tip of the caudal fin.…”