Diet of labrisomid blenny<i>Auchenionchus variolosus</i>(Valenciennes, 1836) (Labrisomidae) during its larval development off central Chile (2012-2013)

2017

Sci. Mar.

The majority of rocky reef fishes have complex life cycles, involving transition from a pelagic to a benthic environment. This means that as they grow, their morphology, behaviour and feeding habits must change. Therefore, shape changes occurring during early development of these fishes will be related to diet changes. The clingfish Sicyases sanguineus was selected for this study, because it displays a noticeable variation in shape from pelagic larvae to juvenile stage, and it is expected that diet composition will change as well. The pattern of shape changes was studied using geometric morphometrics. A set of 9 landmarks were digitized in 159 larval and juvenile fish and the same specimens were used for gut content analysis. Allometric growth was most prominent early in the ontogeny, from 4 to 12 mm. Morphology changed from a thin and hydrodynamic shape to a more robust and deeper body prior to settlement. The diet of the clingfish during larval stages showed preferences for a variety of copepod stages. As individual grows the ingested prey volume increases, but not the number and width of prey. A partial least square analysis showed low covariance between shape changes and diet composition changes in prey number and volume, suggesting that the two processes were temporally decoupled. The biggest shape changes, a lengthening of the visceral cavity and a flattening of the head, occurred up to 12 mm standard length, while the largest feeding differentiation, shifting from copepods to microalgae, occurred after 16 mm. Results suggest that shape changes precede trophic changes in this clingfish species during the transition from a pelagic to a benthic habitat.

Section: Discussioncontrasting

confidence: 71%

Section: Discussionmentioning

confidence: 98%

Feeding variations and shape changes of a temperate reef clingfish during its early ontogeny

Bernal-Durán

2017

Sci. Mar.

“…Marine fish larvae from the Humboldt Current System feed on similar prey items, mainly different stages of calanoid copepods (adults, copepodites, nauplii, eggs) (Valenzuela et al 1995, Llanos-Rivera et al 2004, Vera-Duarte and Landaeta 2016. In our study, larval sandperches, nauplii and copepodites contributed the largest prey number, volume and frequency.…”

Section: Discussionsupporting

confidence: 54%

“…Larvae of cryptic benthic fishes may also feed particularly on gasteropod larvae and cirripede nauplii (clingfish Sicyases sanguineus, Bernal-Durán and Landaeta 2017) and fish eggs (blenny Auchenionchus variolosus) (Vera-Duarte and Landaeta 2016). The inclusion of these types of prey, and also calyptopes, prezoeae and cypris larvae, may explain variations in prey composition among species of sandperches detected by permutation analysis (PERMANOVA).…”

Section: Discussionmentioning

confidence: 99%

Feeding habits and dietary overlap during the larval development of two sandperches (Pisces: Pinguipedidae)

Vera‐Duarte

2017

Sci. Mar.

Summary:Two species of sandperch (Pinguipedidae: Perciformes), Prolatilus jugularis and Pinguipes chilensis, inhabit the coastal waters of the South Pacific. Both species have pelagic larvae with similar morphology, but their diet preferences are unknown. Diet composition, feeding success, trophic niche breadth and dietary overlap were described during larval stages for both species. In the austral spring, larval P. jugularis (3.83-10.80 mm standard length [SL]) and P. chilensis (3.49-7.71 mm SL) during their first month of life had a high feeding incidence (>70%) and fed mostly on copepod nauplii (>80% IRI), Rhincalanus nasutus metanauplii and Paracalanus indicus copepodites. The number of prey ingested was low (mean: 4-5 prey per gut) and independent of larval size; total prey volume and maximum prey width increased as larvae grew. Mouth opening and ingested prey were greater in larval P. jugularis than in P. chilensis, leading to significant differences in prey composition among larval species, in terms of prey number and volume. Pearre's trophic niche breadth was narrow for both species (0.159±0.07 for P. jugularis; 0.156±0.03 for P. chilensis) and independent of larval size. Dietary overlap was high inter-and intra-species in larvae with a mouth gape <900 μm. These results suggest the relative importance of both larval species as primary consumers of the pelagic web in nearshore environments of rocky temperate areas.Keywords: Prolatilus jugularis; Pinguipes chilensis; sandperch, feeding; resource partitioning; Chile.Hábitos alimentarios y superposición de la dieta durante el desarrollo larval de dos blanquillos (Pisces: Pinguipedidae) Resumen: Existen dos especies de blanquillo (Pinguipedidae: Perciformes), Prolatilus jugularis y Pinguipes chilensis que habitan las aguas costeras del Pacífico Sur. Ambas especies tienen larvas pelágicas con morfología similar, pero se desconocen sus preferencias de la dieta. Se describen la composición de la dieta, amplitud del nicho trófico y superposición trófica durante los estados larvales de ambas especies. En primavera, las larvas de P. jugularis (3.83-10.80 mm LE) y P. chilensis (3.49-7.71 mm LE) durante su primer mes de vida tienen alta incidencia alimentaria (>70%) y se alimentan principalmente de nauplii de copépodos (>80%IRI), metanauplii de Rhincalanus nasutus y copepoditos de Paracalanus indicus. El número de presas ingeridas fue bajo (media: 4-5 presas por estómago) e independiente del tamaño larval; el volumen total de presas y el ancho máximo de las presas se incrementó a medida que crecían las larvas de ambas especies. El largo de la mandíbula y el tamaño de las presas fue más grande en larvas de P. jugularis comparado con las de P. chilensis. Esto generó diferencias significativas en la composición de las presas entre especies, en términos de número y volumen de las presas ingeridas. La amplitud del nicho trófico de Pearre fue bajo para ambas especies (0.159±0.07 para P. jugularis; 0.156±0.03 para P. chilensis) e independiente del tamaño larval. La superpos...

“…This suggests resource partitioning between both sympatric species during their pelagic stages. Other marine fish species with pelagic larval stages from central Chile [anchoveta, sandperches (Pinguipedidae), blennies (Labrisomidae)] also fed mostly on early stages of calanoid copepods [eggs, nauplii, copepodites (Balbontín et al ., ; Vera‐Duarte & Landaeta, , )], highlighting the difference in foraging behaviour of larval G. marmoratus .…”

Section: Discussionmentioning

confidence: 99%

Lunar influences in the diet habits and selectivity of larval clingfish Gobiesox marmoratus

Ríos‐Méndez

Kanamori

Journal of Fish Biology

2019

The influence of the lunar cycle on the feeding habits, feeding success and selectivity was tested in situ on larval stages of the clingfish Gobiesox marmoratus (Gobiesocidae). Gobiesox marmoratus larvae and their prey were collected in the water column during the lunar cycle in austral spring 2015 and 2016, in shallow waters (<30 m depth) of El Quisco, central Chile. Feeding incidence was high (80-100%) throughout the moon cycle. The diet was composed of 32 prey items, being gastropod larvae and invertebrate eggs the most important. Prey composition varied among lunar phases with the lowest prey richness during new moon. During 2016, G. marmoratus larvae ingested the lowest number, but the largest prey during new moon. In spring 2015, there were no significant changes in the abundance of each prey taxon in the water column among moon phases, but in spring 2016 there were significant differences in the abundance of cypris and copepod nauplii, particularly between full and new moon. Feeding selectivity index showed that gastropod larvae were positively selected throughout the lunar cycle during spring 2015. In spring 2016, invertebrate eggs were selectively ingested in full moon and third quarter, but at a new moon G. marmoratus larvae selected gastropod larvae. Mean temperature of the water column and its vertical gradient and nocturnal cloud cover influences the feeding success of larval G. marmoratus. Lunar illumination favoured only an increase of richness of prey items. Therefore, nocturnal cloud cover precludes a greater influence of lunar illumination in the larval trophic ecology of this cryptobenthic fish.