Abundance, Activity, and Trophic Patterns of the Redspotted Catshark, Schroederichthys chilensis, on the Pacific Temperate Coast of Chile Author(s): Jose M. Fariña and F. Patricio Ojeda Source: Copeia, Vol. 1993, No. 2 (May 3, 1993), pp. 545-549 Published by: American Society of Ichthyologists and Herpetologists (ASIH) Stable URL: http://www.jstor.org/stable/1447159 Accessed: 12-12-2017 18:26 UTC JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://about.jstor.org/terms American Society of Ichthyologists and Herpetologists (ASIH) is collaborating with JSTOR to digitize, preserve and extend access to Copeia This content downloaded from 146.155.28.60 on Tue, 12 Dec 2017 18:26:56 UTC All use subject to http://about.jstor.org/terms SHORTER CONTRIBUTIONS: ICHTHYOLOGY 545 port, A. Marconato for drawing the DOUGLAS figure, Y. andSHAPIRO, Department of Biology, D. Goulet and T. Liberman for reviews of the Eastern Michigan University, Ypsilanti, Michigan manuscript. 48197; and AMATZIA GENIN, Hebrew University of Jerusalem, H. Steinitz Marine Biology Labo- LITERATURE CITED ratory, P.O. Box 469, Eilat, Israel. Submitted 7 Feb. 1992. Accepted 19 May 1992. Section DE BOER, B. A. 1978. Factors influencing the distri- editor: W. J. Matthews. bution of the damselfish Chromis cyanea (Poey), Po- macentridae, on a reef at Curarao, Netherlands Antilles. Bull. Mar. Sci. 28:550-565. BRAY, R. N. 7981. Influence of water currents and zooplankton densities on daily foraging movements of blacksmith, Chromis punctipinnis, a planktivorous Copeia, 1993(2), pp. 545-549 reef fish. Fish. Bull. 78:829-841. @ 1993 by the American Society of Ichthyologists and Herpetologists DAVIS, W. P., AND R. S. BIRDSONG. 1,973. Coral reef fishes which -forage in the water column. Helgol. ABUNDANCE, ACTIVITY, AND TROPHIC Wiss. Meeresunters. 24:292-306.' PATTERNS OF THE REDSPOTTED CAT- HAMNER, W. M., M. S. JONES, J. H. CARLETON, I. R. SHARK, SCHROEDERICHTHYS CHILENSIS, HAURI, AND D. M. WILLIAMS. 1988. Zooplankton, ON THE PACIFIC TEMPERATE COAST OF planktivorous fish, and water currents on a wind- ward reef face: Great Barrier Reef, Australia; CHILE.-The Bull. redspotted catshark, Schroeder- Mar. Sci. 42-459-479. ichthys chilensis (Guichenot, 1848), is a common HoBsoN, E. S., ANDJ. R. CHESS. 1978. Trophic inshore re- shark that occurs from Anc6n (central lationships among fishes and plankton in the lagoonPerui) to Chilo6 (southern Chile) (Chirichigno, at Enewetak Atoll, Marshall Islands. Fish. Bull. 1974; 76: Compagno, 1984) at depths from 1-50 133-153. m (Mann, 1954). Despite this species being re- KINGSFORD, M. J., AND A. B. MACDIARMID. 1988. ported as one of the most abundant components Interrelationships between planktivorous reef fish and zooplankton in temperate waters. Mar. of Ecol. the nearshore fish assemblages in central and Prog. Ser. 48:103-117. southern Chilean waters (Bahamonde, 1952; POPPER, D., AND L. FISHELSON. 1973. Ecology Miranda, and 1967), little quantitative information behaviour of Anthias squamipinnis (Peters, has 1855) been gathered on basic aspects of its biology (Anthiidae, Teleostei) in the coral habitat ofand Eilat ecology. Based on a sample of 38 individuals (Red Sea). J. Exp. Zool--184:409-424. from southern Chile (Puerto Montt), Baha- SHAPIRO, D. Y. 1979. Social behavior, group mondestruc- (1952) reported a diet consisting pri- ture, and the control-of sex reversal in hermaph- marily of sipunculans. More recently, Miranda roditic fish. Adv. Study Behav. 10:43-102. (1980) reported a sexual aggregation of this spe- 1. 1980. Serial female sex changes after simul- cies occurring during autumn in a central Chil- taneous removal of males from social groups of a coral reef fish. Science 209:1136-1137. ean locality (San Antonio). In this paper, we -. 1986. Intragroup home ranges in a female- document information about abundance, activ- biased group of a sex-changing fish. Anim. Behav. ity, feeding, and reproductive patterns of the 34:865-870. redspotted catshark based on a two-year study - . 1988. Variation of group composition along and the central Chilean coast. Particular at- spatial structure with group size in a sex-changing tention is given to food habits in order to elu- fish. Ibid. 36:140-149. cidate the ecological role of this species in near- ---, AND R. H. BOULON, JR. 1987. Evenly shore dis- communities and its potential impact on persed social groups and intergroup competition important commercial benthic species currently for juveniles in a coral reef fish. Behav. Ecol. So- ciobiol. 21:343-350. being exploited by local artisanal fisheries. STEVENSON, R. A., JR. 1972. Regulation of feeding behavior of the bicolor damselfish (Eupomacentrus Materials and methods.--Redspotted catsharks, partitus Poey) by environmental factors, p.-S. chilensis,278- were collected at two localities on 302. In: Behavior of marine animals, volume the2: ver- central Chilean coast, Punta de Tralca tebrates. H. E. Winn and B. L. Olla (eds). Plenrum (33035'S; 71042'W) and Quintay (33011'S; Press, New York, New York. 71043'W). The substrate of the subtidal zone in VOGEL, S. 1981. Life in moving fluids. Willard Grant both sites consists of a sloping bedrock with Press, Boston, Massachusetts. large rocks and boulders in its shallower portion YoGO, Y. 1986. Protogyny, reproductive behavior and social structure of the Anthiine fish Anthias (0-6 m depth), with an increasing proportion (Franzia) squamipinnis, p. 964. In: Indo-Pacific fishof sand in its deeper portion (6-18 m depth). biology. T. Uyeno, R. Arai, T. Taniuchi, and Large K. plants of the brown kelp, Lessonia trabecu- Matsuura (eds.). The Ichthyological Society ofJa- lata, form an extensive bed extending from 3- pan, Tokyo. 4 m to about 16 m depth. The catsharks were This content downloaded from 146.155.28.60 on Tue, 12 Dec 2017 18:26:56 UTC All use subject to http://about.jstor.org/terms 546 COPEIA, 1993, NO. 2 FALL 0 : 0.4 0 0.3- 0.2- TOTALS .. Bm 0.1N I -i- FALL WINTER SPRING SUMMER FALL WINTER SPRING 1989 1990 Fig. 1. Seasonal 3-. variation WINTER of the relative abun- dance (CPUE) of redspotted catsharks off the central Chilean coast captured during 1989-90. ND = no 2 data. seasonally sampled from May 1989 to Nov. 1990, except in fall 1990, with three 3 x 30 m ex- perimental gillnets consisting of five panels (graded in mesh size from 10-50 mm) that were randomly set in 14, parallel SPRING on the bottom perpen- dicular to the coastline at depths between 5 and 20 m. These gillnets 10 were usually set within the first hour after sunrise and retrieved one hour before sunset. After all fish were removed, the nets were set again overnight and retrieved in the morning. All specimens captured were sexed, measured (TL) to the nearest mm, and 2 weighed to the nearest 1.0 g. Their stomachs, ra0 . intestines, and gonads were removed and fixed in a 5-10% solution of buffered formalin-sea- water mixture, placed in labeled plastic bags, S and transported to the laboratory for further 10 analysis. In the laboratory, the oviducts were inter- nally inspected for presence or absence of en- z capsulated eggs. The diet was estimated from gut contents. Prey items from each stomach were 2 identified to the finest taxonomic resolution, counted, measured and wet-weighed to the 40 45 50 55 60 65 70 nearest g. The importance of each prey species T ot al L e n g t h (cm) was evaluated by calculating an index of relative importance (IRI; Pinkas et al., 1971), as follows: Fig. 2. Seasonal size frequency distributions of IRI = (n + W) FO, where n = percentage nu- redspotted catsharks off the central Chilean coast cap- tured during 1989-90. merical composition, W = percentage gravi- metric composition, and FO = percentage fre- quency of occurrence. Abundance patterns of this species were de- X2 test for goodness of fit, P < 0.001) suggesting termined by using a catch-per-unit-effort that this species is primarily crepuscular and/ (CPUE) measurement. This index was calculat- or nocturnal. ed as the total number of specimens captured The abundance of this species (expressed as in the nets divided by the total number of sam- CPUE) showed a clear seasonal pattern (Fig. 1) pling hours during each season. with maximum values of about 0.37 individuals per hour during fall, minimum values (~0.11) Results. -A total of 214 specimens of S. chilensis during winter, and intermediate values during ranging in size from 41-66 cm in TL was cap- spring and summer. A significantly greater tured during this study; 157 in Punta de Tralca number of females (n = 144) than of males (n and 57 in Quintay. Most of these specimens = 65) was collected throughout study (x2 = 29.9, were caught during the night (190 versus 24; P < 0.01). Seasonal frequency distributions of This content downloaded from 146.155.28.60 on Tue, 12 Dec 2017 18:26:56 UTC All use subject to http://about.jstor.org/terms SHORTER CONTRIBUTIONS: ICHTHYOLOGY 547 body sizes showed a general increase 80- from fall to summer (Fig. 2). This trend was mainly due to a significant increase of female 60- size from fall to summer (One-way ANOVA; F = 17.0, P < 0.001). No seasonal differences S 40in mean body Lw size were detected among males e 20 - (Fig. 2).