Zeiformes: Development and Relationships 



K. A. TiGHE AND M. J. KJEENE 



THE order Zeiformes is diagnosed by a series of derived 

 characters that are not unique to the order (Heemstra. 

 1980): presence of dorsal spines in most forms; presence of anal 

 and pelvic spines in most forms; reduced number of pelvic and 

 caudal rays; absence of orbitosphenoid; absence of subocular 

 shelf; gills 3'/2 (no slit behind last hemibranch); mouth more or 

 less protrusible; no supramaxilla. Other characteristics of the 

 order as presented by Heemstra ( 1 980) are primitive characters 

 that shed little information on the relationships of the order. 

 The literature on Zeiformes is scattered and inadequate. Only 

 the family Zeidae has been examined on a world-wide basis 

 (Bray, 1983). Information on most species is descriptive, with 

 little known about ranges, life history stages, abundance, ecol- 

 ogy, and relationships. Zeiformes are marine and various species 

 occur in the tropical and temperate parts of all oceans in coastal, 

 benthic, epipelagic, mesopelagic, bathypelagic, and bathyben- 

 thic waters (Wheeler et al., 1973). Families are distinguished by 

 presence of vertically elongate or small or no scales, relative 

 body depth, relative mouth size, degree of development of anal 

 and pelvic fin spine(s), number of lateral lines, and morphology 

 of the eye-jaw region. Generic and specific designations are based 

 mainly on morphometnc, meristic, specialized scale, and color 

 characters (Heemstra, 1980). 



The order Zeiformes is presently placed in superorder Acan- 

 thopterygii, near the Beryciformes and other groups that have 

 not attained the perciform level of structural organization. 

 Greenwood et al. (1966) included the Parazenidae, Grammi- 

 colepididae, Zeniontidae, Oreosomatidae, Zeidae, Caproidae, 

 and Macrurocyttidae in the Zeiformes. Heemstra (1980) revised 

 the Zeidae of South Africa and gives a key to all the zeiform 

 families above except the Caproidae which he, like earlier work- 

 ers (Rosen, 1973), feels is only superficially similar to zeiforms 

 and therefore should not be included in the order. He also pro- 

 vides diagnoses for the order and four of the remaining families. 

 Parazen pacificus, not reported from South Africa, is described 

 by Mead (1957). Keys to South African zeids and grammico- 

 lepidids are given by Heemstra ( 1 980), along with a key to adult 

 oreosomatids of the southern Atlantic and Indian Oceans sup- 

 plied to him by Karrer and Eschmeyer. Meristic ranges, number 

 of species, and number of genera for the six families presently 

 in the Zeiformes are given in Table 104. 



Development 



Early life history information on most zeiform species is non- 

 existent (Table 105). There is some information on prejuvenile 

 stages (specialized ontogenetic stages between larvae and ju- 

 veniles) for Oreosomatidae and Grammicolepididae, but none 

 on earlier stages. Early life history data for Zeus faber from egg 

 through juvenile is quite extensive, but such information is 

 incomplete or nonexistent for other zeid species. For the Cap- 

 roidae. larvae of Aniigonia capros and .-1. ruhescens are known, 

 as are all the early stages of Capros aper. Nothing is known for 

 the Parazenidae and Zeniontidae. 



Eggs are known for two species of zeids. They are spherical. 



have a single oil droplet, nonsegmented yolk, and a smooth 

 chorion. Eggs of Zeus faber range from 1 .8-2. 1 mm in diameter 

 with an oil droplet diameter of .32-.40 mm (Sanzo, 1956; De- 

 khnik, 1973; Robertson, 1975a). Those of Zenopsis nebulosus 

 are 2.0-2.25 mm with a droplet of .275-.375 mm (Robertson, 

 1975a). Eggs of Capros aper are about 1.0 mm in diameter, 

 spherical, and have a smooth chorion, unsegmented yolk and 

 a single oil droplet (Arbault and Boutin, 1968a; Sanzo, 1956). 

 Eggs of all other species of zeiform fishes are unknown. 



Newly hatched larvae of Zeus faber were described by Sanzo 

 (1931b). Pigmentation is extensive over body, head and yolk 

 sac with the pigmentation extending to the margin of the dorsal 

 finfold and also on the base of the anal finfold for most of its 

 length (Fig. 212A). Only the tip of the caudal region is unpig- 

 mented. The pectoral and pelvic fin buds are present upon hatch- 

 ing. Preflexion larvae retain the extensive body pigmentation, 

 rapidly become deep-bodied, and show a precocious develop- 

 ment of the pelvic fins (Fig. 212B). Postflexion larvae have 

 almost all fin elements developed (Fig. 212C) and are rapidly 

 assuming the characters of the adult. 



Larval stages are known for both genera in the family Cap- 

 roidae. Newly hatched larvae of Capros aper (Fig. 21 2D) have 

 large stellate melanophores on the dorsal, lateral and ventral 

 surface of the body with a few melanophores on the head and 

 associated with the oil globule. Preflexion larvae (Fig. 212E) 

 become very deep-bodied with an increase in head size. Pig- 

 mentation densely covers the entire body except for the caudal 

 region. A medial serrated ridge occurs on the cranium and other 

 paired serrate ridges develop along the lower jaw and in the 

 supraocular region. Numerous preopercular spines also develop 

 during this stage. Minute spines associated with the developing 

 scales cover the entire body (Fage, 1918). Transformation to 

 the juvenile is gradual and completed by a size of 15-20 mm 

 SL. 



Larvae of Antigonia were described by Uchida (1936) and 

 Nakahara (1962). The larvae are relatively deep-bodied with 

 pigmentation on the peritoneum and head. The median serrate 

 cranial spine, serrate preopercular spines, and serrate ridges on 

 the frontal, mandibular and preopercular regions are character- 

 istic of both A. rubescens and A. capros (Fig. 213A, B), but are 

 totally lost before reaching juvenile sizes of 25 mm. There are 

 several differences between the larvae of the two species but the 

 most obvious is the presence of a vertically directed spine in 

 the occipital region of A. rubescens. 



At least some grammicolepidids exhibit striking proportional 

 changes during growth. Smaller Grammicolepis brachtusculus 

 are very deep-bodied relative to larger ones based on an ex- 

 amination of specimens 70 to 400 mm SL (Quero, 1979). Young 

 Xenolepidichihys dalgleishi also have a relatively deeper body 

 than larger specimens (Myers, 1937) and possess long filamen- 

 tous extensions on some of the dorsal spines and on the first 

 anal spine (Smith, 1949; Fig. 279). These shorten greatly with 

 growth as shown by Myers' (1937) 71 mm SL specimen. 



Oreosomatid adults have mainly overlapping cycloid or cte- 



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