Developmental osteology of Sciaenops ocellatus and Cynoscion nebulosus (Teleostei: Sciaenidae), economically important sciaenids from the western Atlantic

Abstract

Kubicek, K. and Conway, K. W. 2016. Developmental osteology of Sciaenops ocellatus and Cynoscion nebulosus (Teleostei: Sciaenidae), economically important sciaenids from the western Atlantic. -Acta Zoologica (Stockholm) 97: 267-301.The adult skeleton in members of the economically important Sciaenidae is well documented, but information on earlier developmental stages is sparse and often focused on a particular character complex. To generate information on skeletal development in sciaenid fishes, we investigated the ontogeny of the entire skeleton in the western Atlantic Sciaenops ocellatus (Red drum) and Cynoscion nebulosus (Spotted seatrout), which are the focus of successful captive rearing programmes within the southern United States. Development of the skeleton (excluding the basisphenoid and sclerotic bones) is complete in S. ocellatus and C. nebulosus at 14.4 mm SL and 13.5 mm SL, respectively. The basisphenoid did not appear until later in development (21.9 mm SL in S. ocellatus and 19.5 mm SL in C. nebulosus), while the sclerotic bones are not present in the material examined. No major differences are identified between the ossification sequences compiled for each species. Cynoscion nebulosus exhibited variation in the presence/absence of two elements, supraneural 1 and the coronomeckelian. Lastly, we compile and compare available information on skeletal development across members of the Sciaenidae and compare the sequence of ossification compiled for S. ocellatus to that available for Danio rerio and Salminus brasiliensis (entire skeleton), and Chanos chanos (cranium only).Acta Zoologica (Stockholm) 97: 267-301 (July 2016)Kubicek and Conway Skeletal ontogeny of Sciaenops and Cynoscion

Ontogenetic change in predicted acoustic pressure sensitivity in larval red drum (Sciaenops ocellatus)

“…The first three ribs were consistently observed to imprint on the bladder surface in the microCT imagery. The microCT imagery supported the findings of Kubicek and Conway (2016) that the ribs are one of the final bones to calcify; the smallest fish (8.5 mm) had only partially calcified ribs compared with the entirely calcified ribs of the larger individuals. If the ribs impede bladder motion, it would most likely occur in larger fish with calcified ribs rather than in smaller fish with ribs of more flexible cartilage.…”

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

“…1, 2a-c). Although the ventral radials are often progressively larger than the dorsal ones in many other percomorphs, this enlargement is much less pronounced than that of polynemids 18,[22][23][24][25][26][27][28][29][30][31][32][33][34][35] . This specialization in polynemids is coupled with a dramatic anteroventral expansion of the posterior facet of the coracoid that articulates with radial 4.…”

“…2a-c). In the vast majority of other percomorphs, including those proposed to be closely related to polynemids (e.g., mugilids, pleuronectiforms, and sciaenids), the posterior facet of the coracoid is much smaller and often lacks a direct association with radial 4 (e.g., 18,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] ). The articulation of the third pectoral radial with the adjacent radials (2 and 4) and with the coracoid may be reinforced by interdigitations ( Fig.…”

Comparative ontogeny of the feeding apparatus of sympatric drums (Perciformes: Sciaenidae) in the Chesapeake Bay

“…The oral jaws function primarily to capture prey whereas the pharyngeal jaws masticate and further process prey items prior to their passage to the posterior portions of the digestive system (Clifton and Motta, ; Grubich and Westneat, ). The development of skeletal elements is often not well described in the ELHSs, even if the morphology of the adults is well described (Kubicek and Conway, ). Therefore, the structural constraints acting on ELHS fishes are not well understood.…”

“…The goal of this article is to identify when during ontogeny these four sciaenid species are able to functionally partition their foraging habitats within the Chesapeake Bay. Pigmentation and external characteristics that are species‐specific have been described for these sciaenids (Richards ; Fahay ) but until recently there has not been much research on the development of skeletal elements (Kubicek and Conway, ), particularly the feeding apparatus (Govoni, ). Although other factors can influence prey selection for ELHS fishes (e.g., behavior, prey availability, sensory development), study of the anatomy and developmental state of the feeding apparatus can help us better understand the foraging habitat that fishes can functionally exploit, as well as provide a baseline for comparison to other fishes (Poling and Fuiman, ; Anto and Turingan, ).…”