ABSTRACT
Longfin sanddab (Citharichthys xanthostigma) represents a very important fishery resource in Southern and Baja California but are not very well known. The purpose of this study is to provide information on the growth and mortality of longfin sanddab population in the Mexican Pacific Ocean at Baja California, México. Data on growth were obtained for longfin sanddab collected with otter trawls during six cruises off the Western coast of Baja California. A total of 1 017 longfin sanddab were caught over the sampling period, and from 860 specimens, the male to female ratio was 1:1.8. The relationship between total weight (W) and standard length (SL) is described: W=0.00000743 SL3.196 for females and W=0.00000764 SL3.193 for males. Age groups were estimated from length frequency data, and von Bertalanffy annual growth parameters for all fish data combined were the following: L∞=289.2mm SL, k=0.20, t0=-0.73; for males, they were L∞=265.9mm SL, k=0.21, t0=-0.68, and for females, L∞=293.6mm SL, k=0.23, t0=-0.35. Longfin sanddab caught during this study reached a maximum age of 10 years, and at that age, males attained smaller sizes than females. The age groups had a total mortality (Z) rate of 0.82 year-1, a fishing mortality (F) of 0.52 year-1, and a natural mortality (M) of 0.3 year-1. Although the longfin sanddab is not a target species of commercial fisheries, it suffers high mortality as part of the bycatch in the shrimp fishery. Rev. Biol. Trop. 58 (2): 689-705. Epub 2010 June 02.
Se presenta información sobre el crecimiento y mortalidad de la población del C. xanthostigma (lenguado alón) en el Pacífico Mexicano de Baja California, México. Datos sobre su crecimiento fueron obtenidos de peces capturados con red de arrastre durante seis cruceros en la costa Oeste de Baja California, México. Se capturaron 1 017 peces en este periodo. La relación machos:hembras de 860 ejemplares fue de 1:1.2. La relación peso total (W) y longitud estándar (SL) se estimó para hembras: W=0.00000743 SL 3.196 y para machos: W=0.00000764 SL 3.193. La edad de los grupos se calculó con datos de frecuencia por longitud, el crecimiento de von Bertalanffy global fue: L∞=289.2mm SL, k=0.20, t0= -0.73; para los machos: L∞=265.9 mm SL, k=0.21, t0= -0.68 y para las hembras: L∞=293.6mm SL, k=0.23, t0=-0.35, anualmente. La captura de C. xanthostigma durante este estudio alcanzó una edad máxima de 10 años. Los machos alcanzan tallas menores que las hembras a la misma edad. Los grupos de edad tuvieron una tasa de mortalidad total (Z) de 0.82 por año, una mortalidad por pesca (F) de 0.52 por año y mortalidad natural (M) de 0.3 por año. Aunque el C. xanthostigma no es una especie objetivo (comercial), sufre una alta mortalidad indirecta durante la pesca del camarón.
Subject(s)
Animals , Female , Male , Flatfishes/growth & development , Longevity , Mortality , Flatfishes/anatomy & histology , Flatfishes/classification , Mexico , Seasons , SeawaterABSTRACT
Symphurus diabolicus, previously known only from the holotype collected in 501 m west of Isla San Cristobal (Chatham Island), Galápagos Archipelago, is re-described based on the holotype (112.6 mm SL) and 19 additional specimens (61.1-123.5 mm SL) recently collected from deep waters around the Galápagos Archipelago. Symphurus diabolicus is characterized by: an elongate body; narrow head with pointed snout; 1-3-2 ID pattern; 106-110 dorsal-fin rays; 89-96 anal-fin rays; 12 caudal-fin rays; 57-59 total vertebrae; 5 hypurals; extremely small scales; no pupillary operculum; large, prominent eyes, with migrated eye near dorsal margin of head; relatively short postorbital head length; relatively long snout and predorsal lengths; black peritoneum visible through abdominal wall on both sides of body; uniform olive green to dark brown ocular-side coloration with series of prominent, darker brown, elliptical to rectangular, blotches (not usually forming crossbands) along body at bases of dorsal and anal fins; and uniformly whitish or light yellow blind side. Symphurus diabolicus appears to be endemic to the Galápagos Archipelago, and is relatively common (captured at 16 different localities) at depths of 308 to 757 m (observed as shallow as 245 m) in this region. Examination of this expanded series of specimens confirms the validity of S. diabolicus and provides characters to distinguish it from S. microlepis Garman, a similar species known only from the holotype taken at approximately 530 m off Pacific Panama.
Subject(s)
Animals , Male , Female , Flatfishes/classification , Ecuador , Flatfishes/anatomy & histologyABSTRACT
A new eastern Pacific achirid, Trinectes xanthurus, has a distinctive yellow or light caudal fin, without pattern, to contrast with its relatively dark body. This species also has black, posterior margins of the dorsal and anal fins and 21-22 caudal vertebrae, versus 19-20 for its Pacific coast congeners. It usually is found in shallow, continental shelf waters on sand or mud bottoms and ranges from Colombia to El Salvador. The genus Trinectes is represented in the eastern Pacific by four species. A fifth species usually occurs in Pacific slope drainages (freshwater) in Panama. Of these species, only Trinectes fonsecensis is found throughout the tropical eastern Pacific, while the other three coastal species are confined to tropical waters south of the Golfo de Tehauntepec.