Effectiveness of oral Elancobank and Avimix-STk against
Nematopsis (Apicomplexa: Porosporidae) gametocyts infecting
the shrimp Litopenaeus vannamei
Emma J. Fajer-A
´
vila
a,
*
, Marı´a Soledad Morales Covarrubias
a
, Selene Abad-Rosales
a
,
Ana Roque
a,b
, Pablo Meza-Bojo´rquez
a,c
, Crisantema Herna´ndez-Gonza´lez
a
a
Centro de Investigacio´n en Alimentacio´n y Desarrollo, A.C., Unidad Mazatla´n en Acuicultura y Manejo Ambiental. Av. Sa´balo Cerritos s/n,
C.P. 82010, A.P. 711, Mazatla´n, Sinaloa, Me´xico
b
IRTA-Aquaculture Centre. Carr. al Poblenou SN Km 5.5. S. Carlos de la Rapita 43540, Spain
c
Facultad de Ciencias del Mar, Universidad Auto´noma de Sinaloa, Me´xico
Received 8 July 2004; received in revised form 26 October 2004; accepted 2 November 2004
Abstract
Gregarines from Nematopsis genus are a common intestinal parasite infection in the white shrimp, Litopenaeus vannamei,
that is cultured on the Pacific coast of Mexico. Slow growth and mortalities of white shrimp have been associated with
gregarine infections. Control of gregarine infections in Mexican shrimp farms with antibiotics by empirical methods is
becoming increasingly important. However, no effective chemotherapeutic control has been demonstrated. The objective of the
present study was to evaluate the effectiveness of oral administration of sodium monensin, Elancobank and
sulfachloropyrazine, Avimix-STk in removing Nematopsis gametocysts from the intestine of naturally infested cultured
white shrimp (L. vannamei). Four experiments were carried out where different concentrations of antibiotics were administered
to naturally infested shrimp through medicated feed for 5 consecutive days. The experimental system consisted of glass aquaria
containing 8–10 shrimp. Concentrations of antibiotic varied from 2 to 8 g kg
À1
for Elancobank and from 1.5 to 7 g kg
À1
for
Avimix-STk. After 5 days of treatment, both products significantly reduced the mean intensity of Nematopsis gametocysts
when compared to the control. Elancobank treatment reduced Nematopsis gametocysts by 92% and 94% at 5.5 and 6 g kg
À1
,
respectively, and Avimix-STk reduced the numbers of gametocysts by 85% and 83% at 2.5 and 3.5 g kg
À1
, respectively. No
mortalities were recorded for these treatments. The study demonstrates the effectiveness of Elancobank and Avimix-STk used
in medicated feed as a gregarinostats in the control of Nematopsis gametocysts in the white shrimp L. vannamei.
D 2004 Elsevier B.V. All rights reserved.
Keywords: Gregarines; Nematopsis sp; Litopenaeus vannamei; Elancobank; Avimix-STk
0044-8486/$ - see front matter D 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.aquaculture.2004.11.005
* Corresponding author. Tel.: +52 6699 880157(8); fax: +52 6699 880159.
E-mail address: efajer@victoria.ciad.mx (E.J. Fajer-A
´
vila).
Aquaculture 244 (2005) 11 –18
www.elsevier.com/locate/aqua-online