Eleven samples of rose shrimp (Aristeus antennatus) from different areas of the Mediterranean Sea and adjacent Atlantic waters were subjected to morphometric and electrophoretic analyses. The object was to characterize possible population differences that would account for previously reported differences in behavioural patterns observed in commercial fishing activity. Genetic analysis of 27 enzyme systems yielded only fifteen useful loci of which fibre had allele variants, but only two of them were polymorphic within 95%. Morphometric analysis of nine body and appendage measurements revealed significant differences between sampling sites in scaphocerite length, uropodal length, and the length of the articles on the third walking leg. The samples analysed genetically could not be differentiated, but morphological differences were compared between different hydrographic regions of the Mediterranean Basin.

No abstract

Crowth as reíiected by measurcmcnts of diíkrent body parts of thc pink shrimp, Aristerrs nntennatur (abdomen, scaphoceritc, uropods, and segmcnts on thc third and fourth pcrciopods) was rclated to carapacc length by typc-1 regression analysis. Therc wcre diffcrcnccs in the relativc growth of swimming appcndages and pereiopods. For the formcr (abdomcn, uropods, and scaphoccritc) growth was ncgatively allometric at a statistically signilicant levcl, whereas for thc latter (pcrciopod scgmcnts) growth eithcr was isomctric or cxhibitcd a slightly positive allomctry. Comparison of thc measuremcnts bctwccn thc scxes rcvcaled diffcrcnces in growth only for thc iiropods, with thc slopcs of thc rcgrcssion lincs indicating highcr ncgative allomctry in fcmalcs than in males. There was no cvidence of growth discontinuity for any body part ovcr the lifc cycle of individuals of this spccies. Thc results havc bccn comparcd to the findings reported by other investigators working with othcr specics of shrimps, prawns, lobsters, and crabs, and the relativc growth of thc diffcrcnt body parts has bcen rclatcd to the diffcrcnt life stratcgics of cach group. RESUMEN Sc cstudia el crccimicnto rclativo de varias medidas longitudinales dcl cuerpo de la gamba rosada, Aristeus antennatus (abdomen, cscafocerito, uropodos y artc,jos dcl tcrccr y cuarto pcriopodos), rcspecto a la longitud dcl caparazón, mcdiante un análisis de la regresión de tipo-1. Se observan diferencias cn cl crecimiento rclativo dc los apéndiccs natatorios y perciopodos. En los primeros (abdomen, uropodos y escafocerito), el crecimiento fue significativo para una alometria negativa, mientras quc para los scgundos (arte.jos de los pereiopodos), fiic isométrico o con alomctria positiva débil. Comparativamentc entrc scxos, se obscrvan diferencias significativas solo en el crccimicnto de los uropodos, prcscntando las hembras una alomctria negativa más fuerte que los machos. No se obscrvó evidencia dc discontinuidad, en ningún apbndicc, a lo largo del crecimiento de esta cspccic. Los resultados obtenidos se han comparado con los registrados por otros autores en otras especies dc gambas, langostas y cangrejos, dc manera que la discusión se plantea relacionando el crecimiento relativo de estas espccies con las diferentes estrategias vitales de cada grupo.

The objective of this study was to analyze possible morphometric variations in the relationship among various measurements of the body parts of Aristeus antennafus, in the course of a long period of time (30 years). The same appendages were measured in the same way and with the same precision in 1965 and 1995. To avoid differences caused by sexual dimorphism only females were analyzed. The relative growth of the tail appendages of Aristeus anfennatus (telson and externa1 uropod) increased. The scaphocerite and the abdomen length remained practically without change. The length of the articles of the third and fourth pereiopods did not differ, but the total length of the pereiopods was significantly reduced. The existence of possible morphometric changes in the swimming structures in relation to environmental changes is discussed, especially in relation to the decrease of food resource, and to benthic disturbance, caused by increasing fishing pressure. RESUMENEl objetivo del presente estudio es comprobar si existen diferencias morfométricas entre distintas medidas del cuerpo de Aristeus anfennatus, entre dos períodos de tiempo separados 30 años (datos procedentes de 1965 y 1995). Las medidas de los apéndices fueron tomados, en ejemplares hembras, de la misma manera y con la misma precisión en los dos períodos de tiempo. Se observó que el desarrollo de los aptndices caudales, urópodo externo y telson, tienen crecimiento alométrico, aumentando su tamallo relativo con el tiempo. El escafocerito y el abdomen permanencen inalterados, de la misma forma que los artejos de los pereiópodos tercero y cuarto. Estos últimos presentan una ligera tendencia a dismunuir su longitud, aunque de manera no significativa; sin embargo, la longitud total de los pereiópodos presenta una disminución significativa. Se discuten estos cambios de los apéndices natatorios en relación a los cambios ambientales, concretamente en función de la disminución del recurso alimentario y del incremento de la perturbación sobre el sustrato causado por el aumento del esfuerzo pesquero.O Koninklijke Brill NV, Leiden. 1998