CARTILAGE AND BONE DEVELOPMENT IN SCOMBROID FISHES 



Thomas Potthoff, Sharon Kelley, and Joaquin C. Javech 1 



ABSTRACT 



Early development of cartilage and bone was examined in representative species of the scombroid fish 

 families Scombrolabracidae, Gempylidae, Trichiuridae, Scombridae, Istiophoridae, and Xiphiidae from 

 cleared and stained larval size series. Development of the dorsal and anal fins and their pterygiophore 

 supports, development of the neural and haemal spines and hypural complex, and ossification of the 

 vertebrae were studied. The first appearance and location of these skeletal elements in cartilage were 

 noted, and then the direction of new additions was observed. Direction of ossification of these elements 

 was also noted. There were three major kinds of verebral column development: The first was shared 

 by Scombrolabracidae, Scombridae in part - Scombrini, Scomberomorini, and Thunnini; the second was 

 shared by Gempylidae, Sarda (Scombridae in part - Sardini), Istiophoridae, and Xiphiidae; the third kind 

 was found in Trichiurus (Trichiuridae). Saddle-shaped ossifications of the vertebrae were found only 

 in the Scombrolabracidae, and Gempylidae, and Scombridae. Four major kinds of fin and pterygiophore 

 development were observed in the scombroid families: Scombrolabracidae and Scombridae in part - Scom- 

 brini shared one kind; Gempylidae, Trichiuridae, and Scombridae in part - Scomberomorini, Sardini, and 

 Thunnini shared another kind, which had some variations for different taxa; Istiophoridae had the third 

 kind; and Xiphiidae had the fourth kind. Initial ossification of the vertebral column started in one place 

 mScombrolabrax, Gempylidae, Trichiurus, and Xiphias, in two places in Scomber omorus, Sarda, Thun- 

 nus, and Istiophorus, and in four places in Scomber and Acanthocybium. From our investigation, we 

 are just beginning to learn about developmental characters and we cannot interpret their full meaning 

 until more developmental work has been accomplished; we can only state that billfish (Istiophoridae, 

 Xiphiidae) are very different from all other scombroids studied and that Scombrolabrax shows affinity 

 with the scombroids. 



In this paper we describe development of selected 

 osteological features of families in the suborder 

 Scombroidei. We believe that this ontogenetic data 

 will be useful in future taxonomic studies to aid in 

 establishing familial relationships. Under current 

 classification the scombroids comprise various num- 

 bers of families. Greenwood et al. (1966) recognized 

 six families in the suborder Scombroidei: Scom- 

 bridae, Gempylidae, Trichiuridae, Istiophoridae, 

 Xiphiidae, and Luvaridae. Gosline (1968), Potthoff 

 et al. (1980), and Collette et al. (1984) included the 

 family Scombrolabracidae in the Scombroidei, but 

 Johnson (in press) removed it recently. Collette et 

 al. (1984), Leis and Richards (1984), and Tyler et 

 al. 2 removed the Luvaridae from the Scombroidei. 

 For this study we examined ontogenetic series of 

 representative genera of the families Scombrola- 

 bracidae, Gempylidae, Trichiuridae, Scombridae 

 (four tribes), Istiophoridae, and Xiphiidae. 



Southeast Fisheries Center Miami Laboratory, National Marine 

 Fisheries Service, NOAA, 75 Virginia Beach Drive, Miami, FL 

 33149. 



2 Tyler, J. C, G. D. Johnson, I. Nakamura, and B. B. Collette. 

 Osteology and relationships of the oceanic fish Luvarus imperialis 

 (Luvaridae): an acanthuroid not a scombroid. Unpubl. manuscr. 

 National Museum of Natural History, Wash., DC 20560. 



Research on the larvae and young stages of scom- 

 broids, particularly tunas (Richards and Klawe 1972) 

 has been extensive. In general, most papers deal 

 with the external description of the larvae and 

 juveniles (Okiyama and Ueyanagi 1978); few exist 

 that address the internal morphology and develop- 

 ment of scombroids and those are mostly on scom- 

 brids. Kramer (1960) described bone development 

 in the mackerel (Pneumatophorus diego = Scomber 

 japonicus). Potthoff and Richards (1970), Matsu- 

 moto et al. (1972), and Richards and Potthoff (1974) 

 published osteological characters for juvenile scom- 

 brids. Cartilage and bone development were de- 

 scribed in Thunnus atlanticus (Potthoff 1975), Scom- 

 brolabrax heterolepis (Potthoff et al. 1980), and 

 Xiphias gladius (Potthoff and Kelley 1982). Kohno 

 et al. (1984) described fin and cartilaginous fin sup- 

 port development in Scomber japonicus. To our 

 knowledge no developmental studies of cartilage and 

 bone have been made for the scombroid families 

 Istiophoridae and Gempylidae, although a part of 

 the research presented here was published in Col- 

 lette et al. (1984). Since Collette et al. (1984), we 

 have conducted additional research and have dis- 

 covered several errors in our published observations. 

 We have added developmental series of Scomber 



Manuscript accepted February 1986. 

 FISHERY BULLETIN: VOL. 84, NO. 3, 1986. 



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